Exhibit 97.1

1.             Introduction

1.1            Adopted. Upon the recommendation of the Compensation Committee of the Board of Directors (the “Board”) of Denison Mines Corp. (the “Company”), the Board has adopted this Clawback Policy effective October 2, 2023 (the “Effective Date”).

1.2            Purpose. The purpose of this Policy is to provide for the recoupment of certain incentive compensation pursuant to Section 954 of the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010, in the manner required by Section 10D of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), Rule 10D-1 promulgated thereunder, and the Applicable Listing Standards (as defined below) (collectively, the “Dodd-Frank Rules”).

1.3            Administration. This Policy shall be administered by the Compensation Committee. Any determinations made by the Compensation Committee shall be final and binding on all affected individuals.

2.              Definitions

2.1            “Accounting Restatement” shall mean an accounting restatement of the Company’s financial statements due to the material noncompliance of the Company with any financial reporting requirement under the securities laws, including any required accounting restatement (i) to correct an error in previously issued financial statements that is material to the previously issued financial statements (i.e., a “Big R” restatement), or (ii) that corrects an error that is not material to previously issued financial statements, but that would result in a material misstatement if the error were corrected in the current period or left uncorrected in the current period (i.e., a “little r” restatement).

2.2            “Affiliate” shall mean each entity that directly or indirectly controls, is controlled by, or is under common control with the Company.

2.3            “Applicable Listing Standards” shall mean Sec. 1003(h) of the NYSE American LLC Company Guide.

2.4            “Clawback Eligible Incentive Compensation” shall mean Incentive-Based Compensation Received by a Covered Executive (i) on or after the Effective Date, (ii) after beginning service as a Covered Executive, (iii) if such individual served as a Covered Executive at any time during the performance period for such Incentive-Based Compensation (irrespective of whether such individual continued to serve as a Covered Executive upon or following the Restatement Trigger Date), (iv) while the Company has a class of securities listed on a national securities exchange or a national securities association in the United States of America, and (v) during the applicable Clawback Period. For the avoidance of doubt, Incentive-Based Compensation Received by a Covered Executive on or after the Effective Date could, by the terms of this Policy, include amounts approved, awarded, or granted prior to such Effective Date.

2.5            “Clawback Period” shall mean, with respect to any Accounting Restatement, the three completed fiscal years of the Company immediately preceding the Restatement Trigger Date and any transition period (that results from a change in the Company’s fiscal year) within or immediately following those three completed fiscal years (except that a transition period between the last day of the Company’s previous fiscal year end and the first day of its new fiscal year that comprises a period of at least nine months shall count as a completed fiscal year).

2.6            “Company Group” shall mean the Company and its Affiliates.

2.7            “Covered Executive” shall mean any “executive officer” of the Company as defined under Applicable Listing Standards.

2.8            “Erroneously Awarded Compensation” shall mean the amount of Clawback Eligible Incentive Compensation that exceeds the amount of Incentive-Based Compensation that otherwise would have been Received had it been determined based on the restated amounts, computed without regard to any taxes paid. With respect to any compensation plan or program that takes into account Incentive-Based Compensation, the amount contributed to a notional account that exceeds the amount that otherwise would have been contributed had it been determined based on the restated amount, computed without regard to any taxes paid, shall be considered Erroneously Awarded Compensation, along with earnings accrued on that notional amount.

2.9            “Exchange” shall mean The NYSE American LLC.

2.10          “Financial Reporting Measures” shall mean measures that are determined and presented in accordance with the accounting principles used in preparing the Company’s financial statements, and all other measures that are derived wholly or in part from such measures. Share price and total shareholder return (and any measures that are derived wholly or in part from share price or total shareholder return) shall for purposes of this Policy be considered Financial Reporting Measures. For the avoidance of doubt, a measure need not be presented in the Company’s financial statements or included in a filing with the U.S. Securities and Exchange Commission (the “SEC”) in order to be considered a Financial Reporting Measure.

2.11          “Incentive-Based Compensation” shall mean any compensation that is granted, earned or vested based wholly or in part upon the attainment of a Financial Reporting Measure.

2.12          “Received” shall mean the deemed receipt of Incentive-Based Compensation. Incentive-Based Compensation shall be deemed received in the Company’s fiscal period during which the Financial Reporting Measure specified in the applicable Incentive-Based Compensation award is attained, even if payment or grant of the Incentive-Based Compensation occurs after the end of that period.

2.13          “Restatement Trigger Date” shall mean the earlier to occur of (i) the date the Board, a committee of the Board, or the officer(s) of the Company authorized to take such action if Board action is not required, concludes, or reasonably should have concluded, that the Company is required to prepare an Accounting Restatement, or (ii) the date a court, regulator or other legally authorized body directs the Company to prepare an Accounting Restatement. 2.1  Denison values the integrity of its relationships with government agencies, officials, political parties, leaders and candidates throughout the world and expects its Employees and every other person or entity representing Denison to conduct themselves properly when dealing with Public Officials.

3.             Recoupment of Erroneously Awarded Compensation

3.1            Policy. Upon the occurrence of a Restatement Trigger Date, the Company shall recoup Erroneously Awarded Compensation reasonably promptly, in the manner described below. For the avoidance of doubt, the Company’s obligation to recover Erroneously Awarded Compensation under this Policy is not dependent on if or when restated financial statements are filed following the Restatement Trigger Date.

3.2            Process. The Compensation Committee shall use the following process for recoupment:

(i)             First, the Compensation Committee will determine the amount of any Erroneously Awarded Compensation for each Covered Executive in connection with an Accounting Restatement. For Incentive-Based Compensation based on (or derived from) share price or total shareholder return where the amount of Erroneously Awarded Compensation is not subject to mathematical recalculation directly from the information in the applicable Accounting Restatement, the amount shall be determined by the Compensation Committee based on a reasonable estimate of the effect of the Accounting Restatement on the share price or total shareholder return upon which the Incentive-Based Compensation was Received (in which case, the Company shall maintain documentation of such determination of that reasonable estimate and provide such documentation to the Exchange).

(ii)            Second, the Compensation Committee will provide each affected Covered Executive with a written notice stating the amount of the Erroneously Awarded Compensation, a demand for recoupment, and the means of recoupment that the Company will accept.

3.3            Means of Recoupment. The Compensation Committee shall have discretion to determine the appropriate means of recoupment of Erroneously Awarded Compensation, which may include without limitation: (i) recoupment of cash or Company shares, (ii) forfeiture of unvested cash or equity awards (including those subject to service-based and/or performance-based vesting conditions), (iii) cancellation of outstanding vested cash or equity awards (including those for which service-based and/or performance-based vesting conditions have been satisfied), (iv) offset of other amounts owed to the Covered Executive or forfeiture of deferred compensation, (v) reduction of future compensation, and (vi) any other remedial or recovery action permitted by law. The Company Group makes no guarantee as to the treatment of such amounts for the Covered Executive’s income tax purposes or with respect to any other statutory withholdings and shall have no liability with respect thereto. For the avoidance of doubt, appropriate means of recoupment may include amounts approved, awarded, or granted prior to the Effective Date. Except as set forth in Section 3.5 below, in no event may the Company Group accept an amount that is less than the amount of Erroneously Awarded Compensation in satisfaction of a Covered Executive’s obligations hereunder. Notwithstanding the foregoing, any Employee can make a payment when demanded to do so if they believe it necessary in order to preserve their health, safety or well-being or that of another Employee. Afterwards, they must properly document the amount of, purpose of, and circumstances surrounding the payment and report it to the Chief Executive Officer who shall report the same to the Audit Committee.

3.4            Failure to Repay. To the extent that a Covered Executive fails to repay all Erroneously Awarded Compensation to the Company Group when due (as determined in accordance with Section 3.2 above), the Company shall, or shall cause one or more other members of the Company Group to, take all actions reasonable and appropriate to recoup such Erroneously Awarded Compensation from the applicable Covered Executive. The applicable Covered Executive shall be required to reimburse the Company Group for any and all expenses reasonably incurred (including legal fees) by the Company Group in recouping such Erroneously Awarded Compensation.

3.5            Exceptions. Notwithstanding anything herein to the contrary, the Company shall not be required to recoup Erroneously Awarded Compensation if one of the following conditions is met and the Compensation Committee determines that recoupment would be impracticable:

(i)            The direct expense paid to a third party to assist in enforcing this Policy against a Covered Executive would exceed the amount to be recouped, after the Company has made a reasonable attempt to recoup the applicable Erroneously Awarded Compensation, documented such attempts, and provided such documentation to the Exchange; or

(ii)            Recoupment would violate home country law where that law was adopted prior to November 28, 2022, provided that, before determining that it would be impracticable to recoup any amount of Erroneously Awarded Compensation based on violation of home country law, the Company has obtained an opinion of home country counsel, acceptable to the Exchange, that recoupment would result in such a violation and a copy of the opinion is provided to the Exchange.

4.            Reporting and Disclosure

4.1            The Company shall file all disclosures with respect to this Policy in accordance with the requirements of the Dodd-Frank Rules.

5.            Administration

5.1            Indemnification Prohibition. Notwithstanding any provisions to the contrary in an employment agreement or indemnification agreement between the Company and a Covered Executive, no member of the Company Group shall be permitted to indemnify any current or former Covered Executive against (i) the loss of any Erroneously Awarded Compensation that is recouped pursuant to the terms of this Policy, or (ii) any claims relating to the Company Group’s enforcement of its rights under this Policy. The Company may not pay or reimburse any Covered Executive for the cost of third-party insurance purchased by a Covered Executive to fund potential recoupment obligations under this Policy.

5.2            Acknowledgment. To the extent required by the Compensation Committee, each Covered Executive shall be required to sign and return to the Company the acknowledgement form attached hereto as Exhibit A pursuant to which such Covered Executive will agree to be bound by the terms of, and comply with, this Policy. For the avoidance of doubt, each Covered Executive will be fully bound by, and must comply with, the Policy, whether or not such Covered Executive has executed and returned such acknowledgment form to the Company.

5.3            Interpretation. The Compensation Committee is authorized to interpret and construe this Policy and to make all determinations necessary, appropriate, or advisable for the administration of this Policy. The Board intends that this Policy be interpreted consistent with the Dodd-Frank Rules.

5.4            Amendment; Termination. The Board may amend or terminate this Policy from time to time in its discretion, including as and when it determines that it is legally required to do so by any applicable securities laws, SEC rule or the rules of any securities exchange or national securities association in the United States of America on which the Company’s securities are listed.

5.5            Other Recoupment Rights. The Board intends that this Policy be applied to the fullest extent of the law. The Board and/or Compensation Committee may require that any employment agreement, equity award, cash incentive award, or any other agreement entered into be conditioned upon the Covered Executive’s agreement to abide by the terms of this Policy. Any right of recoupment under this Policy is in addition to, and not in lieu of, any other remedies or rights of recoupment that may be available to the Company Group, whether arising under applicable law, regulation or rule, pursuant to the terms of any other policy of the Company Group, pursuant to any employment agreement, equity award, cash incentive award, or other agreement applicable to a Covered Executive, or otherwise (the “Separate Clawback Rights”). Notwithstanding the foregoing, there shall be no duplication of recovery of the same Erroneously Awarded Compensation under this Policy and the Separate Clawback Rights, unless required by applicable law.

5.6            Successors. This Policy shall be binding and enforceable against all Covered Executives and their beneficiaries, heirs, executors, administrators or other legal representatives.

Adopted by the Board of Directors on November 8, 2023.

Exhibit A

Denison Mines Corp.

CLAWBACK POLICY

ACKNOWLEDGEMENT FORM

By signing below, the undersigned acknowledges and confirms that the undersigned has received and reviewed a copy of Denison Mines Corp.’s Clawback Policy (the “Policy”). Capitalized terms used but not otherwise defined in this Acknowledgement Form (this “Acknowledgement Form”) shall have the meanings ascribed to such terms in the Policy.

By signing this Acknowledgement Form, the undersigned acknowledges and agrees that the undersigned is and will continue to be subject to the Policy and that the Policy will apply both during and after the undersigned’s employment with the Company Group. Further, by signing below, the undersigned agrees to abide by the terms of the Policy, including, without limitation, by returning any Erroneously Awarded Compensation to the Company Group reasonably promptly to the extent required by, and in a manner permitted by, the Policy, as determined by the Compensation Committee of the Company’s Board of Directors in its sole discretion.

Exhibit 99.1

Denison Mines Corp.

2023 Annual Information Form 

March 28, 2024

About this Annual Information Form

This annual information form (“AIF”) is dated March 28, 2024. Information in this AIF is stated as at December 31, 2023 unless specified otherwise.

In this AIF, references to the “Company” or “Denison” refer to Denison Mines Corp., its subsidiaries and affiliates, or any one of them, as applicable.

This AIF has been prepared in accordance with Canadian securities laws and contains information regarding Denison’s history, business, mineral reserves and resources, the regulatory environment in which Denison does business, the risks that Denison faces and other important information for Denison’s shareholders.

Financial Information

Unless otherwise specified, all dollar amounts referred to in this AIF are stated in Canadian dollars (“CAD”). References to “US$” or “USD” mean United States dollars.

Financial information is generally derived from consolidated financial statements that have been prepared in accordance with International Financial Reporting Standards as issued by the International Accounting Standards Board.

Caution about Forward-Looking Information

Certain information contained in this AIF and the documents incorporated by reference concerning the business, operations and financial performance and condition of Denison constitutes forward-looking information within the meaning of the United States Private Securities Litigation Reform Act of 1995 and similar Canadian legislation.

Generally, the use of words and phrases like “plans”, “expects”, “is expected”, “budget”, “scheduled”, “estimates”, “forecasts”, “intends”, “anticipates”, or “believes”, or the negatives and/or variations of such words and phrases, or statements that certain actions, events or results “may”, “could”, “would”, “might” or “will” “be taken”, “occur”, “be achieved” or “has the potential to” and similar expressions are intended to identify forward-looking information.

Forward-looking information involves known and unknown risks, uncertainties, material assumptions and other factors that may cause actual results or events to differ materially from those expressed or implied by such forward-looking statements. Denison believes that the expectations and assumptions reflected in this forward-looking information are reasonable, but no assurance can be given that these expectations will prove to be correct. Forward-looking information should not be unduly relied upon. This information speaks only as of the date of this AIF, and Denison will not necessarily update this information, unless required by securities laws.

Examples of Forward-Looking Information

This AIF contains forward-looking information in a number of places, including statements pertaining to Denison’s:

Statements relating to “mineral resources” are deemed to be forward-looking information, as they involve the implied assessment, based on certain estimates and assumptions that the mineral resources described can be profitably produced in the future.

Material Risks

Denison’s actual results could differ materially from those anticipated. Management has identified the following risk factors which could have a material impact on the Company or the trading price of its common shares (“Shares”):

The risk factors listed above are discussed in more detail later in this AIF (see “Risk Factors”). The risk factors discussed in this AIF are not, and should not be construed as being, exhaustive.

Material assumptions

The forward-looking statements in this AIF and the documents incorporated by reference are based on material assumptions made by management of the Company, including the following, which may prove to be incorrect:

Cautionary Notes to U.S. Investors Concerning Resource and Reserve Estimates

As a foreign private issuer reporting under the multijurisdictional disclosure system adopted by the United States, the Company has prepared this AIF in accordance with Canadian securities laws and standards for reporting of mineral resource estimates, which differ in some respects from United States standards. In particular, and without limiting the generality of the foregoing, the terms “measured mineral resources,” “indicated mineral resources,” “inferred mineral resources,” and “mineral resources” used or referenced in this AIF are Canadian mineral disclosure terms as defined in accordance with National Instrument 43-101 — Standards of Disclosure for Mineral Projects (“NI 43-101”) under the guidelines set out in the Canadian Institute of Mining, Metallurgy and Petroleum Standards for Mineral Resources and Mineral Reserves, Definitions and Guidelines, May 2014 (the “CIM Standards”). The Securities and Exchange Commission (the “SEC”) recognizes estimates of “measured mineral resources”, “indicated mineral resources” and “inferred mineral resources”. In addition, the SEC’s definitions of “proven mineral reserves” and “probable mineral reserves” are “substantially similar” to the corresponding definitions under the CIM Standards definition that are required under NI 43-101. Investors are cautioned that while the above terms are “substantially similar” to the corresponding CIM Standards definition, there are differences between the definitions under the United States Securities Exchange Act of 1934, as amended (the “U.S. Exchange Act”) and the CIM Standards definition. Accordingly, there is no assurance any mineral reserves or mineral resources that the Company may report as “proven mineral reserves”, “probable mineral reserves”, “measured mineral resources”, “indicated mineral resources” and “inferred mineral resources” under NI 43-101 would be the same had the Company prepared the mineral reserve or mineral resource estimates under the standards adopted under the U.S. Exchange Act. For the above reasons, information contained in the AIF and other documents incorporated by reference herein containing descriptions of mineral deposits may not be comparable to similar information made public by U.S. companies subject to the reporting and disclosure requirements under the United States federal securities laws and the rules and regulations thereunder. Additionally, investors are cautioned that “inferred mineral resources” have a great amount of uncertainty as to their existence, and great uncertainty as to their economic feasibility. Under Canadian rules, estimates of inferred mineral resources may not form the basis of feasibility or other economic studies, except in limited circumstances. It cannot be assumed that all or any part of an inferred mineral resource will ever be upgraded to a higher category. The term “resource” does not equate to the term “reserves”. Investors should not assume that all or any part of measured or indicated mineral resources will ever be converted into mineral reserves. Investors are also cautioned not to assume that all or any part of an inferred mineral resource exists or is economically mineable.

About Denison

Denison Mines Corp. is engaged in uranium exploration, development and mining. The registered and head office of Denison is located at 1100 – 40 University Avenue, Toronto, Ontario, M5J 1T1, Canada. Denison’s website address is www.denisonmines.com.

The Shares are listed on the Toronto Stock Exchange (“TSX”) under the symbol “DML” and on the NYSE American under the symbol “DNN.”

Computershare Investor Services Inc. acts as the registrar and transfer agent for the Shares. The address for Computershare Investor Services Inc. is 100 University Avenue, 8th Floor, Toronto, ON, M5J 2Y1, Canada, and the telephone number is 1-800-564-6253.

Denison is a reporting issuer in each of the Canadian provinces and territories. The Shares are also registered under the U.S. Exchange Act, and Denison files periodic reports with the SEC.

Acknowledgement

Denison respectfully acknowledges that its business operates in Canada on lands that are in the traditional territory of Indigenous peoples. Denison’s activities encompass the entire mining life cycle, from early-stage exploration to advanced project evaluation, construction, operation, closure and restoration – with the potential for activities to span many decades. As such, Denison is committed to collaborating with Indigenous peoples and communities to build long-term, respectful, trusting, and mutually beneficial relationships and aspires to avoid any adverse impacts of Denison’s activities and operations.

Denison has adopted an Indigenous Peoples Policy, which reflects the Company’s recognition of the important role of Canadian business in the process of reconciliation with Indigenous peoples in Canada and outlines the Company’s commitment to take action towards advancing reconciliation. A copy of the Indigenous Peoples Policy is available on Denison’s website, in Déne, Cree, English and French languages.

Denison’s Head Office is located in the traditional territory of many nations, including the Mississaugas of the Credit, the Anishnabeg, the Chippewa, the Haudenosaunee and the Wendat peoples, and is now home to many diverse First Nations, Inuit and Métis peoples. Denison also acknowledges that Toronto is covered by Treaty 13 with the Mississaugas of the Credit.

Denison’s mining and mineral exploration operations in Saskatchewan, including its office in Saskatoon and various project interests in northern Saskatchewan, are located in regions covered by Treaty 6, Treaty 8 and Treaty 10, which encompass the traditional lands of the Cree, Dakota, Déne, Lakota, Nakota, Saulteaux, within the homeland of the Métis and within Nuhenéné.

Denison’s flagship Wheeler River Uranium Project, in particular, is located in northern Saskatchewan within the boundaries of Treaty 10, in the traditional territory of English River First Nation, in the homeland of the Métis and within Nuhenéné.

Denison’s legacy mines operations in the Elliot Lake region of northern Ontario are located within the boundaries of the Robinson Huron Treaty of 1850, signatories to which include the Serpent River First Nation.

Denison’s Team

At the end of 2023, Denison had a total of 64 active employees, all of whom were employed in Canada. None of the Company’s employees are unionized.

Denison’s Structure

Denison conducts its business through a number of subsidiaries and joint arrangements. The following is a diagram depicting the corporate structure of Denison, its active subsidiaries and corporate and partnership joint arrangements as at December 31, 2023, including the name, jurisdiction of incorporation and proportion of ownership interest in each.

JCU (Canada) Exploration Company, Ltd. (“JCU”) is owned by Denison (50%) and UEX Corporation (“UEX”, 50%). Denison and UEX are parties to a shareholders agreement governing the management of JCU and UEX, a wholly-owned subsidiary of Uranium Energy Corp., was appointed manager for JCU pursuant to the terms of such shareholders agreement.

The Waterbury Lake Uranium Limited Partnership (“WLULP”) is held by Denison (69.33%) and Korea Waterbury Uranium Limited Partnership (“KWULP”) (30.65%) as limited partners and Waterbury Lake Uranium Corporation (“WLUC”) (0.02%), as general partner, with Denison’s aggregate interest in the partnership being 69.35%.

The Formation of Denison Mines Corp.

The Denison name has a long history in the Canadian uranium mining industry. Based on company archives, the Company’s involvement in the uranium mining industry dates back to 1954, when a predecessor to modern Denison acquired uranium claims in the Elliot Lake region of Ontario, Canada.

Denison Mines Corp. was established by articles of amalgamation as International Uranium Corporation (“IUC”) effective May 9, 1997 pursuant to the Business Corporations Act (Ontario) (the “OBCA”). On December 1, 2006, IUC combined its business and operations with Denison Mines Inc. (“DMI”), by plan of arrangement under the OBCA (the “IUC Arrangement”). Pursuant to the IUC Arrangement, all of the issued and outstanding shares of DMI were acquired in exchange for IUC’s shares. Effective December 1, 2006, IUC’s articles were amended to change its name to “Denison Mines Corp.”

Denison subsequently completed a plan of arrangement with Energy Fuels Inc. in 2012 and filed articles of amalgamation on January 1, 2014, July 1, 2014 and July 3, 2014 in connection with Denison’s acquisitions of JNR Resources Inc. and Fission Energy Corp. (“Fission”).

Denison Overview

Uranium Exploration and Development

Denison’s uranium property interests are held directly by the Company and/or indirectly through DMI, Denison Waterbury Corp. and Denison AB Holdings Corp.

Toll Milling

Denison is a party to a toll-milling arrangement through its 22.5% interest in the MLJV, whereby ore is processed for the Cigar Lake Joint Venture (“CLJV”) at the McClean Lake processing facility (the “Cigar Toll Milling”). In February 2017, Denison completed a transaction (the “Ecora Transaction”) with Ecora Resources PLC (“Ecora”), formerly known as Anglo Pacific Group PLC, and its wholly owned subsidiary Centaurus Royalties Ltd. to raise gross proceeds to Denison of $43,500,000. The Ecora Transaction monetized Denison’s future share of the Cigar Toll Milling, providing Denison with the financial flexibility to advance its interests in the Athabasca Basin, including the Wheeler River project.

While the Ecora Transaction monetized certain future toll milling receipts from the Cigar Toll Milling, Denison retains a 22.50% strategic ownership stake in the MLJV and McClean Lake processing facility. See “Denison’s Operations – Cigar Lake Toll Milling – Ecora Transaction”.

Developments Over the Last Three Years

2021…

Project Developments – Proposed Phoenix ISR Operation

In February, Denison announced completion of its 2021 assessments and de-risking plans for the in-situ recovery (“ISR”) mining method planned for Wheeler River’s Phoenix deposit (“Phoenix”). The Wheeler River Joint Venture (“WRJV”) approved a $24.0 million budget for 2021 (100% basis, Denison’s share $19.4 million), to fund activities including the advancement of engineering studies, metallurgical testing, and a 2021 ISR field program. The budget also supported the resumption of activities related to the Environmental Assessment process (the “EA”) for Wheeler River being undertaken in accordance with the requirements of the Canadian Environmental Assessment Act, 2012 and the Saskatchewan Environmental Assessment Act, which had been temporarily suspended in 2020 amidst the significant social and economic disruption resulting from the COVID-19 pandemic and the Company’s commitment to ensure employee safety, support public health efforts to limit transmission of COVID-19, and exercise prudent financial discipline. The results of the 2021 ISR field program supported the permitting and preparation of the FFT (defined below) and the EA and FS processes.

In July, Denison announced, as part of its 2021 ISR field program, it had completed the installation of a five-spot large-diameter commercial scale well (“CSW”) test pattern in the Phase 1 area of Phoenix Zone A (“Phase 1”), to facilitate further hydrogeologic testing and assessment of down-hole permeability enhancement tools. In addition, nine of eleven planned monitoring wells (“MWs”) were installed within the Phase 1 area, to facilitate ongoing observation of the current and future hydrogeological test work – allowing for detailed hydrogeological assessment and water quality sampling.

In August, Denison reported positive interim results from the ongoing ISR metallurgical test program. Test work consistently supported an ISR mining uranium head-grade for Phoenix in excess of the 10 g/L assumed in the Pre-Feasibility Study for the Wheeler River project completed in 2018 (“2018 PFS”). Accordingly, the Company adapted its plans for the remaining metallurgical test work to reflect a 50% increase in the head-grade of uranium bearing solution (“UBS”) to be recovered from the ISR mining wellfield, of 15 grams per litre (“g/L”).

In October, the Company announced the initial results of the highly successful ISR field test program. The program results were highlighted by: (a) achieving commercial-scale production flow rates consistent with those assumed in the 2018 PFS; (b) demonstrating hydraulic control of injected solution during the ion tracer test; (c) establishing breakthrough times between injection and recovery wells consistent with previously prepared estimates; and (d) demonstrating the ability to remediate the five-spot CSW test pattern.

Given consistently positive results from field and laboratory testing, Denison and the WRJV approved the initiation of the formal FS report process for the Phoenix ISR project, and appointed Wood Canada Limited (“Wood”) as independent lead author of the FS.

For further information, see “Mineral Properties - Wheeler River - Evaluation Activities” below.

Project Developments – Wheeler River Regional Exploration

In January, the Company reported the results from its 2020 regional exploration program at Wheeler River, which included the discovery of new high-grade unconformity-hosted uranium mineralization along the K West conductive trend on the western side of the Wheeler River property, approximately four kilometers north-northwest of Phoenix. The uranium mineralization discovered is interpreted to straddle the unconformity contact of the underlying basement rocks and the overlying Athabasca sandstone. In addition to high-grade uranium, the assay results were highlighted by the presence of high-grade nickel.

In February, the Company reported the results from the 2020 exploration and expansion drilling program focused on the area proximal to Phoenix. As part of this program, 19 drill holes were completed for a total of approximately 7,400 metres – all of which were located at, but outside of the extents of the mineral resources currently defined for, Phoenix. The results from the program were highlighted by the intersection of high-grade uranium mineralization in Zone C, where no mineral resource is currently estimated, including: 5.69% U3O8 over 5.0 metres in WR-328D1, located approximately 22 metres northeast of historical mineralized hole WR-368 (1.59% U3O8 over 2.0 metres); and 8.84% U3O8 over 2.5 metres in WR-767D1, located approximately 35 metres to the northeast of WR-328D1.

In July, drill hole GWR-045 was completed as part of the ISR field test program as a MW to the northwest of the CSW test pattern. Based on the mineral resources currently estimated for Phoenix, GWR-045 was expected to intersect low-grade uranium mineralization on the northwest margin of the deposit, approximately 5 metres outside of the boundary of the Phoenix Zone A high-grade resource domain. However, the drill hole intersected a thick interval of high-grade unconformity-associated uranium mineralization grading of 22.0% eU3O8 over 8.6 metres. See “Developments Over the Last Three Years – 2022…” for detail of follow-up drilling results.

Other Project Developments

In April, Denison announced that new high-grade unconformity-hosted uranium mineralization was discovered during the winter 2021 exploration program completed at McClean Lake. The exploration program was operated by Orano Canada, 77.5% owner and operator of the MLJV. Three of the final four drill holes completed during the winter 2021 program returned uranium mineralization at the McClean South target area. Based on subsequently received assay results, the results were highlighted by drill hole MCS-34, which returned 8.67% U3O8 over 13.5 metres (including 78.43% U3O8 over 1.1 metres).

In November, Denison and Orano Canada announced the successful completion of a five-year test mining program deploying the patented Surface Access Borehole Resource Extraction (“SABRE”) mining method on the McClean Lake property. The program was highlighted by the completion of the final stage of the program from May to September 2021 with four mining cavities successfully excavated to produce approximately 1,500 tonnes of high-value ore ranging in grade from 4% U3O8 to 11% U3O8. The program was concluded with no safety, environmental or radiological incidents and confirmed the ability to achieve key operating objectives associated with the test program – including targets for cavity diameter, rates of recovery, and mine production rates. The majority of the ore recovered from the test mining program was transferred to the McClean Lake mill, resulting in the production of approximately 176,000 pounds of U3O8 (Denison’s share: approximately 40,000 pounds of U3O8) in the fourth quarter of 2021.

Financing Developments

In February, the Company completed a public offering (the “February 2021 Offering”) by way of a prospectus supplement to the June 2020 short form base shelf prospectus filed with the securities regulatory authorities in each of the provinces and territories of Canada and a registration statement on Form F-10, as amended (SEC File No. 333-238108) filed with the United States Securities and Exchange Commission (the “2020 Prospectus”). The February 2021 Offering was of 31,593,950 units of the Company at US$0.91 per unit for gross proceeds of approximately US$28.8 million, including the full exercise of the underwriters’ over-allotment option, accounting for 4,120,950 units. Each unit consisted of one Share and one-half of one transferable common share purchase warrant of the Company. Each full warrant was exercisable to acquire one Share of the Company at an exercise price of US$2.00 for 24 months after issuance. Proceeds of the February 2021 Offering were used to fund evaluation and environmental assessment activities in support of the advancement of the proposed Phoenix ISR uranium mining operation at Wheeler River, as well as for general working capital purposes.

In March, the Company completed a private placement of 5,926,000 Shares that qualify as “flow-through shares” for purposes of the Income Tax Act (Canada) at a price of $1.35 per share for gross proceeds of approximately $8 million, the proceeds of which were used on the Company’s exploration activities in 2021 and 2022. The income tax benefits of this issue were renounced to subscribers with an effective date of December 31, 2021.

And in March, the Company announced the completion of a public offering by way of a prospectus supplement to the 2020 Prospectus of 78,430,000 units of the Company at US$1.10 per unit for gross proceeds of approximately US$86.3 million, including the full exercise of the underwriters’ over-allotment option, accounting for 10,230,000 units (the “March 2021 Offering”). Each unit consisted of one common share and one-half of one transferable common share purchase warrant of the Company. Each full warrant was exercisable to acquire one Share of the Company at an exercise price of US$2.25 for 24 months after issuance. Net proceeds of the March 2021 Offering were used to fund the strategic purchase of physical uranium as an investment to support the potential future financing of the advancement and/or construction of Wheeler River and for general, corporate and administrative purposes. Denison ultimately acquired 2.5 million pounds U3O8, at a weighted average price of $36.67 (US$29.66) per pound U3O8 (including purchase commissions of $0.05 (US$0.04) per pound U3O8) and a total cost of approximately $91.675 million. The uranium spot price appreciated to $53.25 (US$42.00) per pound U3O8 by December 31, 2021, resulting in a fair value gain on the Company’s physical uranium holdings of approximately $41.4 million for the year ended December 31, 2021.

In connection with the March 2021 Offering, the aggregate issuances pursuant to prospectus supplements under the 2020 Prospectus neared the 2020 Prospectus limit for aggregate issuance price of securities qualified for issuance by the 2020 Prospectus. Accordingly, Denison terminated its November 2020 equity distribution agreement with Cantor Fitzgerald Canada Corporation, Scotia Capital Inc., Cantor Fitzgerald & Co. and Scotia Capital (USA) Inc., providing for an at-the-market (“ATM”) equity offering program (the “2020 ATM Program”). In 2021, the Company issued 4,230,186 Shares under the 2020 ATM Program at an average price of $0.93 for aggregate gross proceeds of $3,914,000. The Company incurred issue expenses of $466,000, including commissions of $78,000, resulting in net proceeds after commissions of $3,836,000.

In September, the Company filed a short form base shelf prospectus (“2021 Prospectus”) with the securities regulatory authorities in each of the provinces and territories of Canada and a registration statement on Form F-10, as amended (SEC File No. 333-258939) was filed with the SEC. The 2021 Prospectus qualified the public offering for sale of certain securities and combinations of securities, for an aggregate offering amount of up to $250 million during the 25-month period beginning September 16, 2021.

And in September, the Company announced it had entered into an equity distribution agreement with Cantor Fitzgerald Canada Corporation, Scotia Capital Inc., Cantor Fitzgerald & Co. and Scotia Capital (USA) Inc. (“EDA”) providing for a new ATM equity offering program (the “2021 ATM Program”). The intention of the 2021 ATM Program was to allow Denison to, through the agents and from time to time, offer and sell, in Canada and the United States by means of ordinary brokers’ transactions through the facilities of the TSX and/or NYSE American, such number of Shares as would have an aggregate offering price of up to US$50 million. The sale of Shares through the 2021 ATM Program were made pursuant to and qualified by a prospectus supplement to the 2021 Prospectus. In 2021, the Company issued 3,840,000 Shares under the 2021 ATM Program at an average price of $2.08 per Share for aggregate gross proceeds of $7,975,000. The Company incurred issue costs of $748,000, including $160,000 of commissions and $588,000 associated with the set-up of the 2021 Prospectus and 2021 ATM Program, resulting in net proceeds after commissions of $7,815,000.

In October, the Company sold, by private agreement, 32,500,000 common shares of GoviEx Uranium Limited (“GoviEx”), previously held by Denison for investment purposes, and 32,500,000 common share purchase warrants, entitling the holder to acquire one additional common share of GoviEx owned by Denison at an exercise price of $0.80 for a term that expired on April 26, 2023. Denison received gross proceeds of $15.6 million on the sale of the shares and warrants.

Corporate Developments

In January, the Company amended and extended its credit facility with the Bank of Nova Scotia (the “Credit Facility”) to January 31, 2022.

In March, the Company entered into a Participation and Funding Agreement and Letter of Intent with the English River First Nation (“ERFN”) in connection with the advancement of the proposed ISR mining operation at Wheeler River, as well as an Exploration Agreement in respect of Denison’s exploration and evaluation activities within the ERFN traditional territories (the “ERFN Exploration Agreement”). These agreements reflect Denison’s desire to operate its business in a progressive and sustainable manner that respects ERFN rights and advances reconciliation with Indigenous peoples. The agreements provide ERFN with economic opportunities and other benefits, and establish a foundation for future collaboration between Denison and ERFN in an authentic, cooperative, and respectful way.

And in March, the Company announced its inclusion in the S&P/TSX Composite Index – the headline index for the Canadian equity market – effective prior to the open of trading on Monday March 22, 2021.

In May, in connection with the Annual General Meeting of Shareholders, changes were made to the composition of the Company’s Board of Directors, with Mr. Jack Lundin and Ms. Catherine Stefan not standing for re-election at the meeting, and shareholders approving the appointment to the Board of Mr. David Neuburger and Ms. Jennifer Traub. In addition, Mr. Ron Hochstein was appointed Chair of the Board.

In July, Uranium Participation Corporation (“UPC”) completed an arrangement with Sprott Asset Management LP (“Sprott”) and certain affiliates, pursuant to which UPC was acquired by the Sprott Physical Uranium Trust. On completion of that transaction, Sprott became the manager of the Sprott Physical Uranium Trust, and the management services agreement (“MSA”) between Denison and UPC was terminated. In accordance with the terms of the MSA, Denison received a cash payment of approximately $5.8 million in connection with the termination.

In August, Denison completed the acquisition of 50% of JCU from UEX for cash consideration of $20.5 million (the “JCU Acquisition”) following UEX’s acquisition of 100% of JCU from Overseas Uranium Resources Development Co., Ltd. (“OURD”) for $41 million. JCU currently holds a portfolio of 12 uranium project joint venture interests in Canada, including a 10% interest in Wheeler River, a 30.099% interest in the Millennium project (Cameco Corporation (“Cameco”) 69.901%), a 33.8118% interest in the Kiggavik project (Orano Canada 66.1882%), and a 34.4508% interest in the Christie Lake project (UEX 65.5492%).

In December, Denison formally adopted an Indigenous Peoples Policy (“IPP”), which reflects the Company’s recognition of the important role of Canadian business in the process of reconciliation with Indigenous peoples in Canada and outlines the Company’s commitment to take action towards advancing reconciliation. See “Environmental, Health, Safety and Sustainability Matters – Indigenous Peoples Policy and Reconciliation Action Plan” for more details.

2022…

Project Developments – Wheeler River

In February, Denison announced that it completed three drill holes during the fall of 2021 to follow up on the discovery of high-grade uranium mineralization in drill hole GWR-045 at Phoenix, which was located outside of the previously defined extent of the high-grade domain of Phoenix Zone A. All three follow-up holes returned intervals of high-grade uranium mineralization. The results were highlighted by drill hole GWR-049, which was expected to intersect a narrow high-grade interval according to then-current modeling, but instead returned 24.9% eU3O8 over 4.2 metres.

In July, Denison announced that it received approval from the Province of Saskatchewan to prepare, construct, and operate the facilities required to carry out the ISR Feasibility Field Test (“FFT”) planned for the Phoenix deposit. The FFT was designed to use the existing commercial-scale ISR test pattern to perform a combined assessment of the Phoenix deposit’s hydraulic flow properties along with the leaching characteristics that had been assessed through the metallurgical core-leach testing program. The approval was granted by the Saskatchewan Minister of Environment and authorizes Denison to operate “pollutant control facilities”, which is typical for mining operations and allows for the management of material recovered from mineral extraction through to wastewater treatment, discharge, and storage (as applicable). The approval followed the completion of a process involving the review of and consultation on the Company’s permit application and supporting materials related to the FFT.

In August, the Company announced that it had received a Licence to Possess, Use, Store and Transfer a Nuclear Substance from the Canadian Nuclear Safety Commission (“CNSC”). With the receipt of this approval, the Company was fully permitted to operate the FFT facility and carry out the process of recovering a uranium bearing solution from the Phoenix ore body.

Also in August, Denison announced the substantial completion of extensive metallurgical test work to define the mechanical components for the planned Phoenix processing plant as part of the FS underway for Wheeler River. The test work confirmed the ability to produce a yellowcake product that meets industry standard ASTM C967-13 specifications.

In September, the Company reported the completion of the construction and wet commissioning of the lixiviant injection system for the FFT and commencement of the leaching phase of the FFT.

In October, the Company announced that it had successfully recovered uranium bearing solution from the ISR FFT at targeted rates and grades, indicating that the hydrogeological system at Phoenix was responding as expected with pH trends, flow characteristics, and uranium recovery meeting expectations. The preliminary results demonstrated the successful acidification of the test pattern and recovery of uranium using the ISR mining method. Given the highly successful results of the FFT, lixiviant injection ceased, and operations at the Phoenix FFT site transitioned from the leaching phase of the FFT to the neutralization phase.

Also in October, Denison announced a significant regulatory milestone for Wheeler River with the submission of the draft Environmental Impact Statement (“EIS”) to the Saskatchewan Ministry of Environment and the CNSC. The EIS submission outlines the Company’s assessment of the potential effects, including applicable mitigation measures, of the proposed ISR uranium mine and processing plant planned for Wheeler River, and reflects several years of baseline environmental data collection, technical assessments, plus extensive engagement and consultation with Indigenous and non-Indigenous interested parties.

In November, Denison announced the CNSC had completed its conformity review of the draft EIS submitted for the proposed ISR uranium mine and processing plant. The CNSC determined the draft EIS met the requirements for the advancement of the EA process, and the federal technical review of the EIS commenced.

In December, Denison announced highly successful results from long-term core leach metallurgical testing completed to further support the establishment of ISR production and recovery curves to be used in the Phoenix FS. The Company completed a long-term test of a representative intact core sample using specialized equipment to replicate in-situ leaching conditions of the Phoenix deposit. The results were highlighted by: (a) overall recovery of uranium in excess of 97%, demonstrating excellent recovery of uranium from intact high-grade core without the use of permeability enhancement; (b) average recovered solution uranium head grade of 18.3 g/L, exceeding the assumed 15 g/L uranium head grade being used in plant designs; (c) continuous intact core leach testing over a period of 377 days, with uranium recovery head grades consistently maintained above 5 g/L during the final stages of the production curve and then declining during the ramp-down stage; and (d) maximum recovered solution uranium head grade of 49.8 g/L achieved using similar lixiviant concentrations as to those used during the FFT.

And in December, Denison reported that the neutralization phase of the FFT had been successfully completed, advising that sampling of MWs around the FFT site confirmed the successful restoration of the leaching zone to environmentally acceptable pH conditions, as outlined in the applicable regulatory approvals for the FFT. The neutralization phase was initiated in mid-October, following the highly successful completion of the leaching phase of the FFT, and was designed to confirm certain environmental assessment assumptions and verify the efficiency and effectiveness of the neutralization process planned for ISR mining at Phoenix. The FFT was highlighted by the recovery of 14,400 pounds of U3O8 dissolved in solutions generated during the leaching and neutralization phases of the test. The final phase of the FFT, involving the management of the recovered solution, was undertaken in 2023.

Other Project Developments

In January, the Company announced that the CNSC approved an amendment to the operating licence for the MLJV and MWJV operations, which allows for the expansion of the McClean Lake Tailings Management Facility (“TMF”) and accepts the associated revised Preliminary Decommissioning Plan (“PDP”) and cost estimate. See “Denison’s Operations – McClean Lake Mill & Cigar Lake Toll Milling – Mill Licence” for more information.

In March, Denison reported that multiple new high-grade intercepts of unconformity-hosted uranium mineralization were discovered in the final three drill holes completed during the winter 2022 exploration program at the Waterfound property, operated by Orano Canada. Denison holds an effective 24.68% ownership interest in Waterfound through its direct interest in the joint venture and its 50% ownership of JCU. The results were highlighted by drill hole WF-68, which returned a broad zone of uranium mineralization, including a peak interval of 5.91% eU3O8 over 3.9 metres (0.05% eU3O8 cut-off) with a sub-interval grading 25.30% eU3O8 over 0.7 metres, located approximately 800 metres west, along the La Rocque Conductive Corridor, of the previously discovered high-grade mineralization (including 4.49% U3O8 over 10.53 metres) at the Alligator Zone.

In April, Denison completed the sale of 40,000 pounds of U3O8, representing the Company’s share of production from the SABRE test mining program completed at the MLJV in 2021. The uranium was sold at a price of $74.65 (US$59.25) per pound U3O8.

In September, Denison announced that assays received from exploration drilling completed at McClean Lake during the winter of 2022 resulted in a significant expansion of the high-grade unconformity-hosted zone of uranium mineralization discovered in 2021 between the McClean South 8W and 8E pods. Ten drill holes completed during 2022 by Orano Canada returned notable uranium mineralization, including drill hole MCS-58, which returned 2.96% U3O8 over 15.5 metres, including 24.49% U3O8 over 1.5 metres, located approximately 54 metres to the southeast of drill hole MCS-34, which was completed in 2021 and returned a mineralized interval of 8.67% U3O8 over 13.5 metres. Overall, the results from 2022 have successfully expanded the footprint of the mineralized zone to approximately 180 metres in strike length.

Also in September, Denison announced that uranium mineralization was encountered in three of the seven drill holes completed during the summer exploration program at Waterfound, highlighted by drill hole WF-74A, which intersected 4.75% eU3O8 over 13.3 metres, including a sub-interval grading 25.23% eU3O8 over 0.5 metres. The mineralized intersection from WF-74A represents the best mineralized hole drilled on the Waterfound property to date and highlights the potential for the discovery of additional high-grade uranium mineralization further along strike to the west of the Alligator Zone.

Financing Developments

During 2022, the Company issued 11,042,862 Shares under the 2021 ATM Program. The Shares were issued at an average price of $1.83 per share for aggregate gross proceeds of $20,200,000. Denison also recognized issue costs of $599,000 related to the 2021 ATM Program Share issuances which includes $404,000 of commissions and $195,000 other costs associated with the maintenance of the 2021 ATM Program. See “Denison’s Securities – ATM Program Activity”.

Corporate Developments

In January, the Company amended and extended its Credit Facility to January 31, 2023.

Also in January, the Company executed a Repayment Schedule Agreement (the “Repayment Agreement”) with Uranium Industry a.s. (“UI”) pursuant to which the parties negotiated the repayment of the debt owing from UI to Denison with respect to the contingent proceeds of Denison’s sale to UI of its interest in the Gurvan Saihan Joint Venture in Mongolia in 2015 (the “Mongolia Transaction”). In accordance with the Repayment Agreement, the Company received aggregate installment payments in 2022 of US$4,800,000.

And in January, Denison announced the appointment of Ms. Laurie Sterritt to the Board of Directors and the appointment of Mr. Kevin Himbeault as the Company’s Vice President Plant Operations & Regulatory Affairs.

In February, Mr. Jun Gon Kim resigned from the Board. Mr. Yun Chang Jeong joined the Board in early March, filling the vacancy created by Mr. Kim’s resignation.

In April, Denison released its inaugural ESG Report regarding the Company’s environmental, social and governance initiatives and demonstrating its ongoing commitment to sustainability and transparency. Denison’s ESG Reports focus on key ESG topics including the Company’s objective to maintain excellence in corporate governance practices, “best in class” engagement with communities potentially impacted by its activities, diversity in the Company’s workforce, and robust assessments of the environment and biodiversity in the regions within which it operates.

And in April, in connection with the updated PDP and related decrease in the financial assurances required for the MLJV and MWJV reclamation obligation, the Company entered into a further amendment with respect to the Credit Facility pursuant to which the pledged amount of cash required under the Credit Facility was decreased and the additional cash collateral was released.

In May, at Denison’s Annual General Meeting of Shareholders, Mr. Bob Dengler did not stand for re-election to the Board.

In June, Denison and Kineepik Métis Local #9 (“KML”) entered into a Participation and Funding Agreement (the “KML PFA”), which expresses Denison’s and KML’s mutual commitment to the co-development of an agreement supporting the advancement of the Phoenix ISR project. The KML PFA builds on an existing letter agreement between Denison and KML with respect to the support of KML’s contributions to, and participation in, the Federal and Provincial EA process. The parties also entered into an Exploration Agreement (the “KML Exploration Agreement”) in respect of Denison’s exploration and evaluation activities within KML’s land and occupancy area. These agreements reflect Denison’s commitment to the principles set out in the Company’s IPP and advancing reconciliation through taking action.

In October, Denison announced that it entered into an exploration agreement (the “YNLRO Exploration Agreement”) with the Ya’thi Néné Lands and Resources Office (“YNLRO”), Hatchet Lake Denesułiné First Nation, Black Lake Denesułiné First Nation, Fond du Lac Denesułiné First Nation (collectively, the “Athabasca Nations”) and the Northern Hamlet of Stony Rapids, the Northern Settlement of Uranium City, the Northern Settlement of Wollaston Lake and the Northern Settlement of Camsell Portage (collectively, the “Athabasca Communities”) in respect of Denison’s exploration and evaluation activities within the traditional territory of the Athabasca Nations (the “Nuhenéné”). The YNLRO Exploration Agreement expresses the parties’ intention to build a long-term relationship between Denison and the YNLRO, Athabasca Nations, and Athabasca Communities. Denison wishes to conduct and advance its exploration activities in a sustainable manner that respects the Athabasca Nations’ Indigenous rights, advances reconciliation with Indigenous peoples, and provides economic opportunities and other benefits to the Athabasca Communities in an authentic, cooperative and respectful way.

In December, the Company amended the terms of the Credit Facility to extend the maturity date to January 31, 2024, and to increase the credit available under the facility to cover additional standby letters of credit with respect to environmental obligations associated with the FFT activities at Wheeler River.

And in December, Mr. David Bronkhorst retired from his position as Vice President Operations of Denison, remaining with the Company in a technical advisory role. Concurrently therewith, Mr. Himbeault became Vice President Operations & Regulatory Affairs.

2023…

Project Developments – Wheeler River

In August, Denison filed a technical report summarizing the results of (i) the feasibility study completed for ISR mining of the high-grade Phoenix uranium deposit (the “Phoenix FS”); and (ii) a cost update to the 2018 PFS for conventional underground mining of the basement-hosted Gryphon uranium deposit (“Gryphon PFS Update”). The results of the respective studies illustrated that both deposits have the potential to be competitive with the lowest cost uranium mining operations in the world. See “Mineral Properties – Wheeler River” for more details.

In August, reflective of the extensive efforts undertaken by and for the Company, the CNSC deemed complete the Company’s responses to approximately 250 EIS information requests from the Federal Indigenous Review Team (“FIRT”). In November 2023, a subsequent round of information requests was received from the CNSC, seeking additional details for responses not fully accepted by the FIRT. Following the successful resolution of the outstanding information requests, the Company expects to be in position to submit a final version of EIS for consideration at a future hearing of the CNSC. See “Government Regulation – Environmental Assessments – Wheeler River” for more details.

In September, Denison announced the signing of a Shared Prosperity Agreement (“SPA”) with ERFN supporting the development and operation of the Wheeler River project. The SPA received support from a substantial majority of ERFN members who participated in a ratification vote on its key terms. The signing of the SPA follows years of active engagement, including a four-month-long ERFN-led community consultation process ahead of the ratification vote, and represents a significant milestone in the history of both Denison’s relationship with ERFN and the Wheeler River project. See “Environmental, Health, Safety and Sustainability Matters – Indigenous Peoples Policy and Reconciliation Action Plan” for more details.

In October, the Saskatchewan Ministry of Environment confirmed its satisfaction with Denison’s comment responses and proposed EIS updates. The confirmation indicates that Denison is able to finalize the EIS for the purpose of obtaining a Provincial EA approval, however this would delink the currently coordinated Provincial – Federal EA process, which is not expected to provide a meaningful schedule advantage for the Phoenix project. Denison plans to submit one version of the final EIS to both authorities once the FIRT information requests have been resolved.

In November, the Company announced the successful completion of the recovered solution management phase of the ISR FFT. The solution recovered during the FFT was stored on site and this final phase of the FFT involved the treatment of the recovered solution via an on-site purpose-built treatment system. Following treatment, a uranium precipitate product and a treated effluent were produced. The mineralized precipitates were recovered from the process with over 99.99% efficiency. The treated effluent was tested to ensure compliance with permit conditions before being injected into a designated subsurface area.

Other Project Developments

In April, Denison announced the completion of an internal conceptual mining study examining the potential application of the ISR mining method at the Midwest project. The concept study was prepared by Denison during 2022 and formally issued to the MWJV in early 2023. Based on the positive results of the concept study, the MWJV approved the completion of additional ISR-related work for Midwest in 2023 and 2024.

And in April, Denison reported the discovery of high-grade sandstone hosted uranium mineralization approximately 30 metres above the unconformity in drill hole MS 23-10A, which was completed as part of the 2023 winter exploration program at the Moon Lake South property. The intersection in MS 23-10A returned 2.46% U3O8 over 8.0 metres, including a sub-interval grading 3.71% U3O8 over 4.5 metres. This result represents the best drill hole completed on the Moon Lake South property to date.

In November, the Company announced the completion of an inaugural ISR field test program at THT on the Waterbury Lake property. The program included (i) the installation of an eight well ISR test pattern designed to collect an initial database of hydrogeological data, (ii) testing of a permeability enhancement technique, (iii) the completion of hydrogeologic test work, highlighted by the achievement of hydraulic conductivity values consistent with those from the Waterbury PEA, and (iv) the execution of an ion tracer test which established a 10 hour breakthrough time between the injection and extraction wells, while also demonstrating hydraulic control of the injected solution. Overall, the program successfully achieved each of its planned objectives.

Financing Developments

In October, Denison completed a bought deal equity financing resulting in the issuance of 37,000,000 shares at a price of $2.03 (US$1.49) per share for total gross proceeds of $75.1 million (US$55.1 million). The Company intends to use the net proceeds from the offering to fund (1) the advancement of the proposed Phoenix ISR uranium mining operation through the procurement of long lead items (including associated engineering, testing and design) identified during the ongoing Front End Engineering Design (“FEED”) process and the Phoenix FS; (2) exploration and evaluation expenditures; and (3) general corporate and administrative expenses, including those in support of corporate development activities, and working capital requirements.

And in October, the Company completed a $15 million strategic investment in F3 Uranium Corp. (“F3”) with the acquisition of unsecured convertible debentures (the “Debentures”), which carry a 9% coupon and will be convertible at Denison’s option into common shares of F3 at a conversion price of $0.56 per share. F3 has the right to pay up to one third of the quarterly interest payable by issuing common shares. F3 will also have certain redemption rights on or after the third anniversary of issuance of the Debentures and/or in the event of an F3 change of control.

In 2023, the Company sold 200,000 pounds U3O8 at an average selling price of $99.50 per pound U3O8 (US$73.38 per pound U3O8), representing a realized gain on sale of $12.6 million (US$8.8 million), based on Denison’s average acquisition cost of $36.67 per pound U3O8 (US$29.66 per pound U3O8). As at December 31, 2023, the Company’s remaining uranium portfolio had increased in value by 228% since acquisition, to $120.35 per pound U3O8 (US$91.00 per pound U3O8), for an aggregate value of approximately $276.8 million (US$209.3 million).

During 2023, the Company issued 19,786,160 shares under the 2021 ATM Program. The Shares were issued at an average price of $1.91 per share for aggregate gross proceeds of $37,877,000. The Company also recognized costs of $845,000 related to the maintenance of the 2021 ATM Program and Share issuances, which includes $757,000 of commissions, for net proceeds after commissions of $37,130,000. See “Denison’s Securities – ATM Program Activity”.

Corporate Developments

In February, Mr. Yun Chang Jeong resigned from the Board. Mr. Byeong Min An joined the Board in early March, filling the vacancy created by Mr. Jeong’s resignation.

In September, Ms. Elizabeth Sidle was appointed Interim Chief Financial Officer of the Company, in addition to her current role as Vice President Finance, in connection with the leave of absence and subsequent departure from the Company of Mr. McDonald, former Executive Vice President & Chief Financial Officer. Ms. Sidle was appointed Chief Financial Officer in December.

In December, Mr. Geoff Smith joined Denison in the position of Vice President Corporate Development & Commercial, focused on supporting Denison’s investor and customer engagement, the evaluation and execution of growth opportunities and financing arrangements, and the development and oversight of the Company’s uranium sales and contracting strategies.

And in December, the Company amended and extended its Credit Facility to January 31, 2025.

2024 Recent Developments…

In January, Denison and Orano Canada announced that the MLJV has approved a restart of uranium mining operations using the joint venture’s patented SABRE mining method. Mining is planned to commence at the McClean North deposit in 2025, with 2024 activities expected to focus on preparations necessary to ready the existing SABRE mining site and equipment for continuous commercial operations, as well as the installation of pilot holes for the first mining cavities planned for excavation.

And in January, Denison entered into an agreement with Grounded Lithium Corp. (“Grounded Lithium”) with respect to the Kindersley Lithium Project (“KLP”) in Saskatchewan. The agreement includes a series of earn-in options, with each earn-in option being comprised of a cash payment to Grounded Lithium as well as project expenditures to advance KLP. Should Denison complete all three earn-in options, it will have made cumulative cash payments to Grounded Lithium of $3.2 million and have funded $12 million in project expenditures to earn a 75% working interest in the KLP. Upon funding the total amounts of each earn-in option phase, Denison has the right to either exercise the earn-in option and acquire the working interest associated with that phase or move on to the ensuing option phase. The agreement terminates on the earliest of: (i) Denison electing to acquire its working interest and convert to a formal joint venture or to terminate, (ii) June 30, 2028, or (iii) a date as otherwise agreed between the parties.

Also in January, Denison finalized an agreement to sell 100,000 pounds of U3O8 at a price of US$100.00 per pound for delivery in April 2024.

In February, the Company announced its acquisition of fixed and mobile MaxPERF Tool Systems from Penetrators Canada Inc. (“Penetrators”). The MaxPERF Tool Systems have been successfully deployed several times as a method of permeability enhancement in ISR field studies conducted on the Company’s potential ISR mining projects, including at the Phoenix deposit. Penetrators has also agreed to work exclusively with Denison for a 10-year period with respect to the use of the MaxPERF Tool Systems for uranium mining applications, and related services, in Saskatchewan.

In March, Mr. Byeong Min An resigned from the Board. Mr. Jong Ho Hong joined the Board in March, filling the vacancy created by Mr. An’s resignation.

And in March, Denison signed a Sustainable Communities Investment Agreement (the “SCIA”) with the municipalities of the Northern Village of Beauval, the Northern Village of Île-à-la Crosse, the Northern Hamlet of Jans Bay, and the Northern Hamlet of Cole Bay (the “Communities”). The SCIA reflects a common goal of facilitating qualified businesses and workers in benefitting from opportunities associated with the development of the Wheeler River project. The SCIA establishes commitments for funding to support community development initiatives, focused on with consideration towards contributing to the current and future economic prosperity and sustainability of the Communities by promoting economic development and investments in capital projects, job creation and training, housing, education, and other initiatives. In consideration for such contributions to the Communities’ initiatives, the Communities have provided their consent and support for the Wheeler River project and have committed, amongst other things, to support all regulatory approvals issued for the Wheeler River project related to exploration, evaluation, development, operation, reclamation, and closure activities.

The Uranium Industry 2023

In 2023, both the uranium spot price and long-term price continued their upward trend. In the spot market, the price of uranium started the year at US$48.00 per pound U3O8 and closed the year at the annual high of US$91.00 per pound U3O8 – a ~90% increase year over year. A material price increase was also observed in the long-term market, with the long-term price steadily increasing throughout the year from US$51.00 per pound U3O8 at December 31, 2022 to US$68.00 per pound U3O8 at December 31, 2023. This US$17.00 per pound U3O8 increase in the long-term price is the largest annual gain since 2007.

Positive momentum in uranium markets has continued in early 2024. In January 2024, the spot price for uranium surpassed US$100 per pound U3O8, a level viewed by market commentators as an important threshold. Prior to 2024, the spot uranium price had not been above US$100 per pound U3O8 since 2008. The Company believes the current uranium market environment demonstrates notable similarities to the last time prices reached these levels. In the early 2000s, highly enriched uranium (“HEU”) and other former Soviet Union supplies remained a market hangover from the Cold War with elevated inventory levels weighing on prices for years with limited new supply coming online. Ultimately, this period of low prices, compounded by supply shocks, created a favourable environment for uranium prices in future years when paired with significant expected demand growth driven by ambitious plans for nuclear power in China. Meaningful new sources of supply were scarce, due to years of under investment, at a time of rapid demand growth. The Japanese tsunami and associated Fukushima nuclear incident in 2011 disrupted the market and set in motion a similar period of low prices and excess inventories. Given the sudden shut-down of the Japanese nuclear fleet and other reductions in demand, excess uranium inventories and excess enrichment capacity, which provided the ability to create additional uranium supply, catalyzed a downward shock to price. During this extended period, prices were below the cost of production for many producers, leading to the shutdown of multiple mines and a sharp reduction in investment in new exploration and development activities across the sector. After years of supply discipline, and the accumulation of physical uranium positions amongst financial investors, the market reached an inflection point followed by four consecutive years of price increases between 2020 and 2023, reflective of a market transitioning to be driven by the cost of future production rather than by the availability of surplus inventories. Looking ahead, the Company believes the increasing demand for nuclear energy, coupled with a prolonged period of limited investment in new supply creates supply-demand dynamics that are supportive of strong uranium prices for the foreseeable future.

Uranium Demand

There is global focus on the importance of nuclear power in enabling the achievement of carbon emission goals. At COP28 in Dubai in December 2023, this recognition was further enshrined as over 20 nations pledged to triple nuclear energy generation capacity by 2050 in an effort to avert the adverse consequences of climate change. The Company believes this wide-spread government support for nuclear energy represents a paradigm shift that is expected to favourably impact nuclear demand fundamentals and ultimately supports the Company’s expectations for robust uranium markets.

In addition to the renewed commitment to nuclear from powerhouse nations like Japan, Korea, France, and the United States in recent years, multiple governments in 2023 adopted stances increasingly supportive of nuclear power generation, including Belgium, Italy, and Sweden.

Positive nuclear demand developments occurred in many nations in 2023. Three notable nuclear reactor projects that had been in construction for a decade reached commercial operations in 2023 including Vogle 3 in the United States, Olkiluoto in Finland, and Kakrapar in India. In China, additional reactors reached commercial operations and construction began on a further five reactors. China continues to be a major source of growth for nuclear energy, with UxC LLC (“UxC”) expecting that over half of the 76 reactors builds it is currently projecting to be completed by 2030 will be in China. In Canada, Ontario Power Generation announced refurbishment plans for its Darlington nuclear plant and ongoing refurbishment continued at the Bruce Power nuclear facility in Ontario. Additionally, small modular reactors are being advanced in both Ontario and Saskatchewan. In Japan, two reactors were restarted in 2023, breaking a streak of two years without a restart. Taken together, forecasts from UxC for global reactor units and nuclear capacity in 2035 is 532 units and 504 gigawatts electrical (“GWe”) installed capacity (estimated as of Q4’2023) – representing a 29% increase in global nuclear power generation from 433 units producing 392 GWe in 2023. With expected growth accelerating, UxC’s base case estimate of global uranium demand in 2035 increased 6%, from 240 million pounds U3O8 estimated as of Q4’2022, to 254 million pounds U3O8 estimated as of Q4’2023.

While spot uranium prices increased significantly during 2023, the impact on price from physical uranium funds appears to be significantly less than in 2022. UxC estimates that physical uranium funds net additions to inventory levels were 5 million pounds U3O8 in 2023 compared to secondary sources of demand, including physical uranium funds, acquiring at least 20 million pounds U3O8 in 2022, and an estimated 53 million pounds U3O8 in 2021.

UxC estimates total utility demand for 2023 at 198 million pounds U3O8 representing a 3% increase over 2022 demand levels.

Primary Uranium Supply

On the supply side, UxC estimates uranium production for 2023 at 141 million pounds U3O8, which represents a 9% increase over 2022 production levels, largely due to the ramp-up of the McArthur River mine and a modest production increase at Olympic Dam. On balance, 2023 is expected to result in a significant primary supply shortfall of approximately 29% of total demand, or 57 million pounds U3O8.

In Q4’2023 UxC estimated 2024 primary production to increase to 162 million pounds U3O8, with the production increase being supported by increasing production from Kazatomprom in Kazakhstan offset by lower production from Orano’s Arlit mine in Niger. However, in early 2024, Kazatomprom announced 2024 production is expected to be lower than previous guidance due to scarce availability of sulphuric acid in the region as well as delays in completing construction for newly developed production areas. Additionally, UxC estimates secondary supplies for 2024 are projected at 34 million pounds of U3O8 equivalent (“U3O8e”), which is a significant reduction from 56 million pounds U3O8e of secondary supplies estimated in 2023, 65 million pounds U3O8e in 2022, and 98 million pounds U3O8e in 2021. Strong secondary demand in past years has accelerated the process of drawing down these secondary sources of supply. With this rapid decline in secondary supplies, the market is expected to continue its shift from an inventory-driven market to a production-driven market in the coming years.

Nuclear sentiment also continues to be supported by an increased focus on energy security in the aftermath of Russia’s invasion of Ukraine. While the Russian invasion continues to be the most impactful geopolitical event, the importance of security of supply was further magnified in July of 2023, as a military coup was waged in Niger which led to the withdrawal of foreign embassy personnel, and a temporary shutdown of Orano’s uranium mining operations. In 2022, Niger ranked as the seventh largest uranium producing country. The Russian invasion of Ukraine in February 2022 continues to cause significant turmoil in the global nuclear fuel market. Russia is a significant supplier of enriched uranium to the rest of the world, operating 46% of the world’s uranium enrichment capacity. In 2021, Russian enrichment comprised 31% of European Union enrichment purchases and 28% of US utility enrichment purchases. While deliveries of material from Russia to Western utilities continue, increased demand for non-Russian supply has led to significantly increased prices for uranium processing services. From December 2021 to December 2023, the long-term price of conversion and enrichment services increased by 94% and 148%, respectively. In the short- to medium-term, in order to increase enriched uranium production in the supply-constrained Western enrichment market, Western enrichers are expected to input more UF6 (overfeed) into their centrifuges in order to maximize production capacity. As a consequence, Western utilities in aggregate will require more natural uranium feedstock to produce the same quantity of enriched uranium (i.e., new enrichment contracts require higher tails assay levels). In 2023, US and European utilities demonstrated a path towards reduced reliance on Russian nuclear fuel supply and are understood to be increasingly favouring Western supply chains. In December 2023, a US bill to curb imports of Russian uranium was approved by US Congress. While the bill awaits approval by the US Senate, the bill is indicative of an ongoing shift of uranium supply chains away from Russia, which increasingly favours North American uranium supply.

Russia is also a major player in uranium logistics, with significant quantities of uranium from Central Asia typically transported through Russia to Russian ports for delivery to Western uranium conversion facilities. UxC estimates Kazakhstan and Uzbekistan combined for 45% of global primary uranium production in 2023. As a result, logistics of uranium shipped through Russia remains an item of concern to uranium end users. Some uranium has been successfully shipped from Kazakhstan to Canada via the Trans-Caspian International Transport Route, which does not include transit through Russia; however, reports indicate that this route is subject to operational limitations.

Outlook

Overall, nuclear demand growth appears poised for acceleration led by a shifting energy mix towards reliable decarbonized energy at a time when limited investment over the past decade has supported bringing new uranium mine supply online. While some idled or curtailed production from existing uranium mining operations has retuned to the market, it is expected that (i) production costs associated with further potential restart projects will be higher than previous levels due to inflation and labour shortages, and (ii) lag times to bring on much of the potential new or greenfield mine supply remains several years away.

The accelerated decline in secondary sources of uranium supply in recent years, the depletion of existing mines, the expectation of rising tails assay at Western enrichment plants, and growing future reactor demand, point to larger supply deficits during the second half of this decade that will be difficult to balance without considerable and rapid investment in new large-scale uranium mining projects. Given that uncovered utility uranium requirements for the period from 2024 to 2040, not including typical inventory building or restriction on existing supply agreements with Russia, are estimated at 2.2 billion pounds U3O8, it is evident that the necessary new future sources of supply required by the market have not yet been secured by utilities, and that the response from incumbent suppliers that have signed significant long-term supply contracts in recent years has not satisfied the needs of utility customers, meaning that there is good reason to expect further phases of utility procurement directed at incentivizing new projects to meet long-term demand needs.

Competition

The uranium industry is small compared to other commodity or energy industries. Uranium demand is international in scope, but supply is characterized by a relatively small number of companies operating in only a few countries. Primary uranium production is concentrated amongst a limited number of producers and is also geographically concentrated with 83% of the world’s production in 2024 projected to be coming from only four countries: Kazakhstan, Canada, Namibia and Australia. Producers compete for market share and commercial terms necessary to support project economics. This is complicated by the influence of state-owned-enterprises that operate within the uranium mining industry, often producing uranium supply as part of a vertical integration strategy that may be less sensitive to uranium pricing than those operating uranium mines as a commercial business.

Competition is somewhat different amongst exploration & development companies focused on the discovery or development of a uranium deposit. Exploration for uranium is being carried out on various continents, but in recent years development activities by public companies have been generally concentrated in Canada, Africa and Australia. In Canada, exploration has focused on the Athabasca Basin region in northern Saskatchewan. Explorers have been drawn to this area by the high-grade uranium deposits that have produced some of the most successful uranium mining operations in recent history. Within the Athabasca Basin region, exploration is generally divided between activity that is occurring in the eastern portion of the Basin and the western portion of the Basin. The eastern portion of the Basin is a district that is defined by rich infrastructure associated with existing uranium mines and uranium processing facilities. Infrastructure includes access to the provincial power grid and a network of provincial all-weather highways. By comparison, in the western portion of the Basin, there are no operating uranium mines or processing facilities and access to the provincial power grid is not currently available. Several uranium discoveries have been made in the Athabasca Basin region in recent years, and competition for capital, high-quality properties, and professional staff can be intense.

Mineral Reserves and Mineral Resources

NI 43-101 requires mining companies to disclose mineral reserve and resource estimates using the subcategories of proven mineral reserves, probable mineral reserves, measured mineral resources, indicated mineral resources and inferred mineral resources.

Each of Chad Sorba, P.Geo, Denison’s Vice President Technical Services and Project Evaluation, and Andy Yackulic, P.Geo., Denison’s Vice President Exploration, is a “Qualified Person” in accordance with the requirements of NI 43-101, and has reviewed and approved all disclosure of scientific or technical information in this AIF.

Denison Mineral Reserves and Mineral Resources

The following tables show the Company’s current estimates of mineral reserves and mineral resources as at December 31, 2023. For more information about the Company’s material properties, see “Mineral Properties”.

Proven Mineral Reserve Estimates (1,15)

Probable Mineral Reserve Estimates (1,2,3,4,15)

Measured Mineral Resource Estimates (1,5,7,15)

Indicated Mineral Resource Estimates (1,5,7,15)

Inferred Mineral Resource Estimates (1,6,15)

Historical Estimates

A qualified person has not done sufficient work to verify and classify these historical estimates as current mineral resources for the Company or confirm their reporting of resources is in accordance with NI 43-101 categories, though the Company has no reason to believe the information is not relevant or reliable. The Company is not treating this information as current mineral resources. As these do not represent material properties for the Company at this time, the Company does not currently have any plans to conduct work to verify the historical estimates.

JCU Estimates

Historical Indicated Mineral Resource Estimates (15)

Historical Inferred Mineral Resource Estimates (15)

McClean South

McClean South Historical Estimates (16)

Notes to Mineral Resource and Mineral Reserve & Historical Estimates Tables:

Mineral Properties

Denison’s mineral property interests are located in the Athabasca Basin region of northern Saskatchewan, the majority of which are located in the eastern portion of the Athabasca Basin, which is host to considerable existing infrastructure including uranium mines and mills, and provincial powerlines and highways (see location map, below). As at December 31, 2023, Denison has direct interests in 34 mineral properties in the Athabasca Basin, comprised of 228 claims covering approximately 385,000 hectares. Denison holds additional indirect interests in various uranium project joint ventures in Canada through its 50% ownership interest in JCU.

Denison’s exploration and evaluation operations in Saskatchewan, including its office in Saskatoon and various project interests in northern Saskatchewan, are located in regions covered by Treaty 6, Treaty 8 and Treaty 10, which encompass the traditional lands of the Cree, Dakota, Déne, Lakota, Nakota, Saulteaux, within the homeland of the Métis and within Nuhenéné.

Location Map of Denison’s Athabasca Basin Mineral Properties

Athabasca Basin Overview

The Athabasca Basin covers an area of approximately 100,000 square kilometres in northern Saskatchewan and northeastern Alberta. The Athabasca Basin is one of the principal uranium-producing districts in the world and is host to the world’s highest-grade and some of the world’s largest uranium mines and deposits, including the McArthur River mine and Cigar Lake mine located in the eastern Athabasca Basin.

The uranium deposits are classified as unconformity-associated (also unconformity-related and –type) deposits owing to their spatial association with a major unconformable contact between a relatively undeformed Proterozoic sedimentary basin (the Athabasca Basin) and underlying metamorphosed and deformed Archean to Palaeoproerozoic basement rocks.

A broad variety of unconformity-associated deposit shapes, sizes, and compositions have been discovered. Two distinct varieties have been classified; 1) ‘egress-style’ polymetallic lenses at and above the unconformity, with variable and often highly elevated base metal and rare earth elements (“REE”) contents, and 2) ‘ingress-style’ vein sets within basement rocks, with typically lower base metal and REE contents.

Egress-style deposits can occur in the sandstone, directly above the unconformity (e.g., Cigar Lake, Sue A and B), straddling the unconformity (e.g., Phoenix, Collins Bay B Zone, Midwest Main, Midwest A, McClean North, Key Lake) or perched high above the unconformity (certain zones at McClean Lake, Midwest, Cigar Lake). Ingress-style deposits are located in the basement rocks (e.g., Gryphon, Huskie, Eagle Point, Sue C, Sue E, Millennium, Arrow, Triple R); however, the Millennium deposit and, to an extent, the Gryphon deposit also contain subordinate mineralization at and above the unconformity. The Shea Creek deposits contain mineralization in the basement, deep in the basement, at the unconformity, and perched in the sandstone. In some deposits, there is a plunge to the mineralized pods from sandstone-hosted to basement-hosted within deposit–scale strike lengths (e.g., the Rabbit Lake-Collins Bay-Eagle Point trend, Sue trend deposits, McClean North).

The Athabasca unconformity-associated deposits are typically related to graphite-bearing structural zones within the metamorphosed and deformed Archean to Palaeoproerozoic basement rocks, which are often termed ‘corridors’ or ‘trends’. Alteration ‘halos’ or ‘envelopes’ tend to surround the mineralization, most notably in the overlying sandstone, and provide an enlarged exploration target through the detection of diagnostic alteration clays and geochemical pathfinder elements. Empirical exploration for the deposits typically involves mapping of structural corridors/trends by geophysical methods (dominantly electromagnetics, resistivity, or magnetics), followed by drill testing, given the buried or blind nature of the deposits below glacial cover or Athabasca sandstone, respectively. Drill core is subject to a variety of sampling and analytical methods to determine possible vectors toward mineralization, and downhole surveying is commonplace to test for elevated radioactivity or reconcile geophysical responses. The significant number of Athabasca uranium discoveries to date has also led to the development of numerous exploration models which are commonly used to facilitate interpretations and prioritize target areas.

Historical uranium production in the Athabasca Basin region used conventional open pit mining methods, such as the operations at Rabbit Lake, Cluff Lake, Key Lake and McClean Lake. Later in the mine life of Cluff Lake and Rabbit Lake, there was a transition to underground mining of other deposits on those properties.

The discovery of high-grade deposits such as Midwest, McArthur River and Cigar Lake in the 1980s did not immediately lead to production. The combination of challenging ground conditions (most notably the friable and water-saturated Athabasca sandstone conditions above the mineralization), depth, and the high-grade nature of the deposits, required extensive research and development to design safe extraction methods before production was possible. Production from McArthur was achieved in the early 2000s, while Cigar Lake only initiated production in 2014. Production from these mines was only made possible by their unique combination of high grades (average grades > 10% U3O8) and large scale (>300 million lbs U3O8), as well as the development of innovative mining techniques, including ground freezing combined with either raise-bore mining or the use of the jet-boring mining system (“JBS”). The Midwest deposits are smaller in size than McArthur River and Cigar Lake, and remain undeveloped.

In terms of mineral processing, each historical mining operation included a dedicated processing plant: Cluff Lake, Key Lake, Rabbit Lake and McClean Lake operations included on-site processing plants. Due to the rising cost of construction for such facilities and the availability of highways and other infrastructure in Saskatchewan’s North, processing of ores has transitioned to toll milling at existing facilities. McArthur River ore production is toll milled at the Key Lake mill, while Cigar Lake production is toll milled at the McClean Lake mill. With the suspension of operations at Rabbit Lake in 2016 and McArthur River in 2018, in part due to a prolonged slump in the global uranium market, only the Cigar Lake mine and the McClean Lake mill continued to operate and produce yellowcake in Saskatchewan during 2021.

In response to the COVID-19 pandemic, the Cigar Lake Joint Venture, operated by Cameco, temporarily suspended production at the Cigar Lake mine from the end of March 2020 until September 2020, and then again from the end of December 2020 until April 2021. Coordinated therewith, the MLJV suspended operations at the McClean Mill for the duration of the suspended production.

In February 2022, Cameco announced its intention to restart uranium production at its McArthur River uranium mine and Key Lake uranium mill in 2022 — while at the same time outlining its intention to, together with Orano, continue to limit overall production at McArthur River and Cigar Lake well below full production rates. In February 2023, Cameco announced that due to improved uranium market conditions, Cigar Lake will instead target operating at its licensed capacity of 18 million pounds U3O8 and the plan will be for McArthur River to increase production to 18 million pounds U3O8 per year starting in 2024. In February 2024, Cameco announced that it produced 15.1 million pounds U3O8 at Cigar Lake and 8.3 million pounds U3O8 at McArthur River in 2023 and reiterated plans to produce 18 million pounds U3O8 at each of Cigar Lake and McArthur River in 2024.

In January 2024, Denison and Orano Canada announced that the MLJV has approved a restart of uranium mining operations using the joint venture’s patented SABRE mining method. Mining is planned to commence at the McClean North deposit in 2025, with 2024 activities expected to focus on preparations necessary to ready the existing SABRE mining site and equipment for continuous commercial operations, as well as the installation of pilot holes for the first mining cavities planned for excavation.

Wheeler River

The Wheeler River project is the largest undeveloped uranium project in the infrastructure-rich eastern portion of the Athabasca Basin region, in northern Saskatchewan. The project is host to the high-grade Phoenix and Gryphon uranium deposits, discovered by Denison in 2008 and 2014, respectively, and is a joint venture between Denison (90%) and JCU (10%). Denison is the operator/manager of the project.

In June 2023, Denison announced the results of (i) the Phoenix FS completed for ISR mining of the high-grade Phoenix deposit and (ii) the Gryphon PFS Update for conventional underground mining of the basement-hosted Gryphon deposit.

The results of the Phoenix FS and Gryphon PFS Update were summarized in the technical report entitled “NI 43-101 Technical Report on the Wheeler River Project, Athabasca Basin, Saskatchewan, Canada”, filed on August 9, 2023 with an effective date of June 23, 2023 (the “Wheeler Report”), authored by David Myers P.Eng., Lorne Schwartz P.Eng., and Paul O’Hara P.Eng. of Wood Canada Limited (“Wood”); Gordon Graham P.Eng. of Engcomp Engineering and Computing Professionals Inc. (“Engcomp”), Mark Hatton P.Eng. of Stantec Consulting Ltd., Dan Johnson P.E., RM SME, then of WSP USA Environment and Infrastructure Inc., Gregory Newman P.Eng. of Newmans Geotechnique Inc., Jeffrey Martin P.Eng. of Ecometrix Incorporated, Mark Mathisen C.P.G. SLR International Corporation (“SLR”), William McCombe P.Eng. of Hatch Ltd., Cliff Revering P.Eng. of SRK Consulting (Canada) Inc. (“SRK”), and Geoffrey Wilkie P.Eng. of CanCost Consulting Inc. The Wheeler Report is available on the Company’s website, under its profile on the SEDAR+ website at www.sedarplus.ca and on EDGAR at www.sec.gov/edgar.shtml.

The Phoenix FS reflects several design changes and the results of a rigorous technical de-risking program completed by Denison following the publication of the 2018 PFS and confirms robust economics and the technical viability of an ISR uranium mining operation with low initial capital costs and a high rate of return. Highlights of the Phoenix FS include:

The Gryphon PFS Update was targeted at the review and update of capital and operating costs. Mining and processing plans remain largely unchanged from the 2018 PFS aside from minor scheduling and construction sequencing optimizations. The key points include:

The Wheeler River project description is a summary supported by the Wheeler Report. The Wheeler Report is recommended to be read in its entirety for a more fulsome understanding of the technical aspects of the Wheeler River project. The conclusions, projections and estimates included in this description are subject to the qualifications, assumptions and exclusions set out in the Wheeler Report and in the “Risk Factors” set forth below; in particular, any advancement or development of the Wheeler River project is subject to attainment of any required approvals, agreements or resources, including capital funding.

Property Description, Location and Access

Project Area and Location

Wheeler River is located in the eastern Athabasca Basin, approximately 600 km north of Saskatoon, 260 km north of La Ronge, and 110 km southwest of Points North Landing, in northern Saskatchewan. Wheeler River is comprised of a total of 19 contiguous mineral claims covering 11,720 ha and hosts the Phoenix Deposit and Gryphon Deposit. The Gryphon Deposit is located approximately 3 km northwest of the Phoenix Deposit. The centre of the Wheeler River property is located approximately 35 km northeast of the Key Lake mill and 35 km southwest of the McArthur River mine along Provincial Highway 914.

The Wheeler River property is located within the boundaries of Treaty 10 (entered into between the Government of Canada and the First Nations People of Saskatchewan and Alberta). It is also located within the traditional territory of the English River First Nation, within the homeland of the Métis and within Nuhenéné.

Location Map, Showing Regional and Proposed Infrastructure.

Permits, Environmental Liabilities, Royalties and other Encumbrances

For the conduct of its work on the Wheeler River property to-date, Denison has obtained all permits known to be required. The advancement of Wheeler River will be subject to comprehensive permitting, approvals and licensing processes. Environmental and permitting considerations for future work are discussed in detail in Section 20 of the Wheeler Report. See “Risk Factors” for more information on this and other potential risks that may affect access, title or the right or ability to perform work on the property.

Wheeler River is subject to royalties on mineral sales and profits levied by the Province of Saskatchewan in accordance with Part III of The Crown Mineral Royalty Regulations. See “Government Regulation - Canadian Royalties” for further details. There is also a 10% Net Profits Interest associated with the property held by the WRJV in proportion to the ownership interests of each WRJV participant, of which Denison is also a beneficiary. There are no other back-in rights or third-party royalties applicable to this property.

Denison has recognized certain environmental liabilities associated with the Wheeler River project in connection with historical and current operations, including without limitation, exploration activities, camp facilities and the feasibility field test conducted at Phoenix in 2022 and 2023.

Access

Access to Wheeler River is by road, helicopter, or fixed-wing aircraft. Vehicle access to Wheeler River is by Highway 914, which terminates at the Key Lake mill. The Wheeler River Project is well located with respect to all-weather roads. The haul road between the Key Lake and McArthur River operations lies within the eastern part of the Wheeler River property.

In 2021, Denison resurfaced the 7.2 km access road from km36 (turn off from Highway 914) to the Phoenix site to facilitate regular vehicle travel and heavy equipment mobilization and demobilization from the site. The sand and gravel used to resurface the road were sourced in very close proximity to the property. The Fox Lake Road between Key Lake and McArthur River provides access to most of the northwestern side of the Wheeler River property. Gravel and sand roads and drill trails provide access by either four-wheel-drive or all-terrain vehicles to the rest of the property.

Climate / Operating Season

The climate is typical of the continental sub-arctic region of northern Saskatchewan, with temperatures ranging from +32°C in summer to -50°C in winter. Winters are long and cold, with mean monthly temperatures below freezing for seven months of the year. Winter snowpack averages 70 to 90 cm. Field operations are possible year-round, except for limitations imposed by lakes and swamps and the periods of break-up and freeze-up. Freezing of surrounding lakes, in most years, begins in November, and break-up occurs around the middle of May. The average frost-free period is approximately 90 days.

The average annual precipitation for the region is approximately 450 mm, of which 70% falls as rain, with more than half occurring from June to September. Snow may occur in all months but rarely falls in July or August. The prevailing annual wind direction is from the west, with a mean speed of 12 km/h.

It is expected that any future mining operations will operate year-round. Field operations currently operate year-round and are conducted from Denison’s Wheeler River camp, 4 km south of the Gryphon Deposit and 3 km southwest of the Phoenix Deposit.

Sufficiency of Surface Rights, Power, Water, Personnel

There are sufficient surface rights for the planned future mining operations, including sufficient land to construct various facilities, including potential waste disposal areas and the process plant.

The site currently generates its own power. The Wheeler River property is also well located with respect to the provincial power grid. Fuel and miscellaneous supplies are stored in the existing warehouse and tank facilities at the Wheeler River camp. Abundant water is available from the numerous lakes and rivers in the area.

To support the local economy, Denison has made a commitment to utilize local businesses whenever possible. Many of these local businesses are also Indigenous-owned. However, given the nature of Denison’s remote operations, mining supplies and labour will also need to be sourced from major centres such as Saskatoon, Regina, and possibly others.

Topography, Elevation, Vegetation

The Wheeler River Project is characterized by a relatively flat till plain with elevations ranging from 477 to 490 metres above sea level (“masl”). Throughout the area, there is a distinctive north-easterly trend to landforms resulting from the passage of Pleistocene glacial ice from the northeast to the southwest. The topography and vegetation at the Wheeler River Project are typical of the taiga forest common to the Athabasca Basin area of northern Saskatchewan.

The area is covered with overburden from 0 to 119 m in thickness. The terrain is gently rolling and characterized by forested sand and dunes. Vegetation is dominated by black spruce and jack pine, with occasional small stands of white birch occurring in more productive and well-drained areas. Lowlands are generally well drained but can contain some muskeg and poorly drained bog areas with vegetation varying from wet, open, non-treed vistas to variable density stand of primarily black spruce and tamarack, depending on moisture and soil conditions. Lichen growth is common in this boreal landscape, mostly associated with mature coniferous stands and bogs.

Significant Risks

Reference should be made to the “Risk Factors” and the factors and risks described in the Wheeler Report for more information.

History

Ownership

The Wheeler River Project was staked on July 6, 1977 and was vended into the WRJV pursuant to the Wheeler River joint venture agreement dated December 28, 1978 (the “Wheeler JV Agreement”), among AGIP Canada Ltd. (“AGIP”), E&B Explorations Ltd. (“E&B”), and Saskatchewan Mining Development Corporation (“SMDC”), with each holding a one-third interest.

On July 31, 1984, all parties divested a 13.3% interest in the WRJV and allowed Denison Mines Limited, a predecessor company to Denison, to earn a 40% interest. On December 1, 1986, E&B allowed PNC Exploration (Canada) Co. Ltd. (“PNC”) to earn a 10% interest from its 20% interest. In the early 1990s, AGIP sold its 20% interest to Cameco (successor to SMDC), resulting in Cameco holding 40%. In 1996, Imperial Metals Corporation (successor to E&B), sold its remaining 8% interest to Cameco and 2% interest to PNC. Participating interests became Cameco 48%, PNC 12%, and Denison 40%.

In late 2004, Denison earned a further 20% interest from the other parties to the WRJV, after which the participating interests were Denison 60%, Cameco 30%, and JCU (a successor to PNC) 10%. Since November 2004, Denison has been the operator of the WRJV.

In January 2017, Denison executed an agreement with the partners of the WRJV to fund 50% of Cameco’s ordinary share of joint venture expenses in 2017 and 2018 in exchange for a transfer of a portion of Cameco’s interest. Based on spending during 2017, Denison increased its interest in the WRJV to 63.3%. In October 2018, Denison acquired all of Cameco’s remaining interest and the WRJV became Denison (90%) and JCU (10%).

In August 2021, Denison acquired an additional 5% indirect interest in the Wheeler River Project through the acquisition of a 50% ownership interest in JCU. Denison currently has an effective 95% ownership interest in the WRJV.

Development History

The Phoenix project is still at the advanced exploration stage and, except in connection with the FFT, no production has occurred on the property to-date.

Geological Setting, Mineralization and Deposit Types

Regional, Local and Property Geology

Wheeler River is located near the southeastern margin of the Athabasca Basin in the southwest part of the Churchill Structural Province of the Canadian Shield. The Athabasca Basin is a broad, closed, and elliptically shaped cratonic basin with an area of 425 km east-west by 225 km north south. The bedrock geology of the Athabasca basin area consists of Archean and Paleoproterozoic gneisses unconformably overlain by up to 1,500 m of flat-lying unmetamorphosed sandstones and conglomerates of the mid-Proterozoic Athabasca Group.

Wheeler River is located near the transition zone between two prominent litho-structural domains within the Precambrian basement, namely the Mudjatik Domain to the west and the Wollaston Domain to the east. The Mudjatik Domain is characterized by elliptical domes of Archean granitoid orthogenesis separated by keels of metavolcanic and metasedimentary rocks. The Wollaston Domain is characterized by tight to isoclinal, northeasterly trending, doubly plunging folds developed in Paleoproterozoic metasedimentary rocks of the Wollaston Supergroup, which overlie Archean granitoid orthogenesis identical to those of the Mudjatik Domain. The area is cut by a major northeast-striking fault system of Hudsonian Age. The faults occur predominantly in the basement rocks but often extend up into the Athabasca Group due to several periods of post-depositional movement.

Local geology is very much consistent with the regional geology.

Phoenix

Phoenix was discovered in 2008 and can be classified as an unconformity-associated deposit of the unconformity-hosted variety. The deposit straddles the sub Athabasca unconformity approximately 400 m below surface and comprises three zones (A, B, C and D) which cover a strike length of about 1.1 km. The Phoenix deposit’s zones A and B comprise an exceptionally high-grade core, averaging 46.0% and 22.3% U3O8, respectively. A lower-grade shell surrounds the high-grade core. The basement mineralization at Zone A occurs within local dilation zones near both ends of the deposit associated with the interpreted cross faults. No mineral resources have been estimated for either Zone C or Zone D.

Phoenix is interpreted to be structurally controlled by the WS Shear, a prominent basement thrust fault which occurs footwall to a graphitic-pelite and hanging wall to a garnetiferous pelite and quartzite unit. A minor amount of basement, fracture-hosted mineralization occurs within local dilation zones near both ends of the deposit associated with the interpreted cross faults.

The mineralization within the Phoenix deposit is dominated by massive to semi-massive uraninite associated with an alteration assemblage comprising hematite, dravitic tourmaline, illite and chlorite. Secondary uranium minerals, including uranophane and sulphides, are trace in quantity. Average nickel, cobalt, and arsenic concentrations are at the low end of the range found in other uranium deposits in the Athabasca basin.

Phoenix Zones A and B exhibit elevated concentrations of certain rare earth elements. While there is a strong correlation between the REEs and uranium mineralization, the correlation between heavy rare earth elements and the high-grade uranium domains is comparatively stronger than the correlation between high-grade uranium mineralization and light rare earth elements.

Gryphon

Gryphon was discovered in 2014 and can be classified as an unconformity-related deposit of the basement-hosted variety. The deposit occurs within southeasterly dipping crystalline basement rocks of the Wollaston Supergroup below the regional sub-Athabasca Basin unconformity. The deposit is located from 520 to 850 m below surface, has an overall strike length of 610 m and dip length of 390 m, and varies in thickness between 2 and 70 m, depending on the number of mineralized lenses present.

A series of 24 stacked lenses referred to as the A, B, C, D and E-series are controlled by reverse fault structures, which are largely conformable to the basement stratigraphy and dominant foliation. The A, B and C series of lenses comprise stacked, parallel lenses which plunge to the northeast along the G-Fault which occurs between hangingwall graphite-rich pelitic gneisses and a more competent pegmatite-dominated footwall. A ubiquitous zone of silicification (Quartz-Pegmatite Assemblage) straddles the G-Fault and the A, B and C series of lenses occur in the hangingwall of, within, and in the footwall of the Quartz-Pegmatite Assemblage, respectively. The D series lenses occur within the pegmatite-dominated footwall along a secondary fault zone (Basal Fault) or within extensional relay faults which link to the G Fault. The E series lenses occur along the G-Fault, up-dip and along strike to the northeast of the A and B series lenses, within the upper basement or at the sub-Athabasca unconformity. The E series of lenses differ from the remaining sets of lenses as they are the only ones to not follow the local scale plunge of the deposit, rather the mineralization is located planar to foliation and tight to the unconformity. To date, the E series lenses are the only lenses to host unconformity mineralization at Gryphon.

Mineralization within the Gryphon deposit lenses is dominated by massive, semi-massive or fracture-hosted uraninite associated with an alteration assemblage comprising hematite, dravitic tourmaline, illite, chlorite and kaolinite. Secondary uranium minerals, including uranophane and carnotite, and sulphides are trace in quantity.

Gangue mineralogy is dominated by alteration clays (illite, kaolinite, chlorite), dravite and hematite with minor relict quartz, biotite, graphite, zircon, and ilmenite. Only trace concentrations of sulphides are noted, comprising galena, chalcopyrite, and pyrite. Notable concentrations of molybdenum and lithium are also noted within and around the mineralization, represented visually as lepidolite and molybdenite, respectively.

Mineral Deposit Type

The Phoenix and Gryphon Deposits are classified as an Athabasca Basin unconformity-associated (also unconformity-related and -type) uranium deposit. Phoenix straddles the unconformity contact between the Athabasca sandstone and underlying basement, signifying the unconformity as a major fluid pathway for uranium mineralization. Gryphon is primarily hosted in the basement rocks, with minor portions of the deposit situated at the unconformity.

Unconformity-associated uranium deposits are pods, veins, and semi-massive replacements consisting of mainly uraninite, close to basal unconformities, in particular those between Proterozoic conglomeratic sandstone basins and metamorphosed basement rocks.

The uranium deposits in the Athabasca Basin occur below, across, and immediately above the unconformity, which can lie within a few metres of surface at the rim of the Basin to over 1,000 m deep near its centre. The deposits are formed by extensive hydrothermal systems occurring at the unconformity’s structural boundary between the older and younger rock units.

Two end-members of the deposit model have been defined: (1) a sandstone-hosted egress-type model (i.e., Midwest A deposit) involved the mixing of oxidized, sandstone brine with relatively reduced fluids issuing from the basement into the sandstone; and (2) a basement-hosted, ingress-type deposits (i.e., Rabbit Lake deposit) formed by fluid-rock reactions between oxidizing sandstone brine entering basement fault zones and the local wall rock.

Unconformity-type uranium deposits are surrounded by extensive alteration envelopes. In the basement, these envelopes are generally relatively narrow but become broader where they extend upwards into the Athabasca Group for tens of metres to even 100 m or more above the unconformity. Hydrothermal alteration is variously marked by chloritization, tourmalinization (high boron, dravite), hematization (several episodes), illitization, silicification/desilicification, and dolomitization. Modern exploration for these types of deposits relies heavily on deep-penetrating geophysics and down-hole geochemistry.

Recently, basement-hosted deposits have become more recognized as a viable exploration target through the development of Eagle Point mine and the discovery of deposits such as Millennium, Triple R, and Arrow. Exploration typically requires the recognition of significant fault zones within basement metasediments (often associated with graphite) with associated clay and geochemical alteration haloes.

Exploration

Excluding the years 1990 to 1994, exploration activities comprising airborne and ground geophysical surveys, geochemical surveys, prospecting, and diamond drilling have continuously been carried out on the Wheeler River property from 1978 to present.

After the discovery of the Key Lake mine in 1975/1976, the Key Lake exploration model has emphasized the spatial association between uranium deposition at, immediately above, or immediately below the unconformity with graphitic pelitic gneiss units in the basement subcrop under the basal Athabasca sandstone. The graphitic pelitic gneiss units are commonly intensely sheared and are highly conductive in contrast to the physically more competent adjoining rock types that include semipelitic gneiss, psammite, meta-arkose, or granitoid gneiss. From the late 1970s to the present, the Key Lake model has helped discover blind uranium deposits throughout the Athabasca Basin, although it is worth noting that the vast majority of EM conductors are unmineralized.

Following the Key Lake exploration model, EM techniques were the early geophysical methods of choice for the Wheeler River Project area from 1978 to 2004. More than 152-line km of electromagnetic (“EM”) conductors have been delineated on the Wheeler River Project to depths of 1,000 m through the quartz-rich Athabasca Group sandstones that are effectively transparent from an EM perspective. These conductors or conductor systems were assigned a unique designation, and follow-up exploration drilling successfully identified several zones of uranium mineralization.

Since 2004, Denison has completed ground geophysical surveys over the Wheeler River property, including the DC resistivity surveys that identified the drilling target that led to the discovery of the Phoenix deposit in 2008. In 2004, an airborne survey GEOTEM EM and magnetic survey collected data covering the entire Wheeler River Project while a FALCON airborne gravity gradiometer survey in 2005 targeted the unconformity uranium mineralization. A helicopter-borne versatile time-domain electromagnetic (“VTEM”) magnetic-radiometric survey was conducted over the Wheeler River Project in 2013 in attempt to remove noise in the interpretation of a previous survey.

Drilling

Diamond drilling has been the principal method of exploration and delineation of uranium mineralization after initial geophysical surveys. Drilling can generally be conducted year-round. Since 1979, over 1,000 diamond drill holes and 84 reverse circulation (“RC”) drill holes totalling in excess of 490,000 m have been completed on the Wheeler River property.

Phoenix

Since 2008, 315 drill holes totalling 145,982 m have delineated the Phoenix deposit. The Phoenix deposit area has been systematically drill tested over approximately 1 km of strike length at a nominal spacing of 25 to 50 m northeast-southwest by 10 m northwest-southeast (perpendicular to strike). Delineation diamond drilling at Phoenix was primarily done with NQ sized core (47.6 mm diameter) in holes WR-249 through WR-275 and HQ sized core (63.5 mm diameter) reducing to NQ at 350 m in holes thereafter, with most holes successfully penetrating into the basement. Some additional infill holes were drilled primarily to test the spatial continuity of the mineralization. The bulk of the flat-lying high-grade mineralization is positioned at and sub-parallel to the unconformity.

Phoenix Drilling Completed by Denison

Gryphon

The first exploration drilling in the Gryphon area began in 1988 and continued intermittently through 2013. In 2014, Denison completed a drilling campaign of 23 holes for 16,666 m which included the Gryphon discovery hole WR-556. Following the discovery of Gryphon, definition drilling has been carried out on all lenses (A through E series). To date, Denison and predecessor companies have drilled 278 holes, totalling 156,600 m, in the immediate Gryphon deposit area, of which 216, totalling 119,720 m drilled between 1985 and 2017, have delineated the Gryphon deposit. Diamond drilling at Gryphon was primarily done with NQ sized core (47.6 mm diameter) with most holes angled between 60° and 79° to the northwest.

Gryphon Drilling Completed by Denison

Sampling, Analysis and Data Verification

See “Athabasca Exploration: Sampling, Analysis and Data Verification” for details.

Mineral Processing and Metallurgical Testing

Phoenix

Test programs, including various forms of leaching tests, process plant circuit tests, and effluent and solid waste streams treatment steps, have been conducted on the Phoenix deposit before and during the Phoenix FS. The results of the tests indicate the ability to leach uranium using in-situ techniques, allow a representative recovery curve to be assembled, and indicate geochemistry requirements for subsurface remediation.

Leaching testwork for Phoenix has included:

The main objective of the FFT was to demonstrate injection of lixiviant and recovery of uranium bearing solution from the CSW test pattern. The FFT was a full-scale proof of concept of the ISR method in a thick and high-grade area of the deposit likely to be targeted for initial production.

The following process plant testwork has been conducted on the Phoenix deposit. The results informed the criteria and design of the process plant described in the Phoenix FS, with specific attention paid to environmental requirements for waste streams and to end-product quality.

Gryphon

In 2017, Denison undertook a metallurgical testwork program at SRC Geoanalytical Laboratories, directly managed by Denison. Denison also completed a parallel test program at the Orano Service d’Études de Procédés et Analyses (“SEPA”) laboratories at Bessines-sur-Gartempe, France. SRC and SEPA are ISO 17025 certified. The objectives of the testwork programs were to further develop the optimum processing conditions and collect additional data to support engineering design, including confirming the adequacy of the McClean Lake mill for processing Gryphon ore:

Mineral Resource and Mineral Reserve Estimates

Mineral resources are reported in accordance with CIM Definition Standards (CIM, 2014) and prepared in accordance with the CIM Estimation of Mineral Resources and Mineral Reserves Best Practice Guidelines (CIM, 2019).

The estimates for Phoenix are presented assuming ISR extraction. The estimates for Gryphon are presented assuming underground mining methods.

Denison is not aware of any environmental, permitting, legal, title, taxation, socio-economic, marketing, political, or other relevant factors that could materially affect the mineral resource estimate, other than what is described in this AIF and the Wheeler Report. See “Risk Factors”.

Phoenix Mineral Resource Statement, Effective Date June 23, 2023

Notes:

Due to the high-grade nature of the Phoenix deposit, additional infill drilling related to installation of an ISR well field will provide further definition of the high-grade uranium mineralization within the deposit footprint, leading to possible changes in the estimated uranium content. However, it is estimated that, given the current drill density within the deposit, any possible changes to the estimated uranium content would not be material based on the current geological understanding of the deposit.

Phoenix Mineral Reserve Statement, Effective Date June 23, 2023

Notes:

The aggregate mine feed to the plant has been estimated to contain 56.7 million pounds U3O8. This represents 80.6% recovery of the measured and indicated mineral resource available for in-situ recovery and is the mineral reserve estimate determined from this study.

The FS analysed the varying recovery rates amongst hydrogeological units (“HGUs”) and was a significant step in the definition of ISR efficacy for this deposit. Recovery varies based on the permeability and geochemistry of the HGUs and their interaction with adjoining units. To characterize the behaviour of ISR, a hydraulic tomography model was developed to estimate permeabilities in three dimensions throughout the deposit. These values were used in a hydrogeologic simulation to calculate in-situ flows between injection and recovery wells through the HGUs. The resulting flow field was input to a geochemical model to simulate recovery per well, per HGU. This recovery result was used to revise the well layout and individual flows in the hydrogeologic model. Several iterations of this modelling system were run to realize the optimized result.

The recovery curve used as a basis for the geochemical model was obtained empirically from metallurgical testing.

In determining the conversion of mineral resources to mineral reserves for the application of the ISR mining method to a heterogeneous unconformity style deposit, several modifying factors were considered. These include, but were not restricted to, mining, processing, metallurgical, infrastructure, economic, marketing, legal, environmental, social, and government factors. While a significant portion of the Phoenix mineral resource is classified as measured, demonstrating the highest degree of confidence in relation to geologic parameters, the cumulative assessment of all modifying factors supports the classification of probable mineral reserves for a large portion of the deposit, with a requirement of higher confidence in the modifying factors achieved through operating experience.

Estimated proven mineral reserves are based on the 2022 FFT, which provided additional confidence in the ISR method and ability to recover U3O8 within the tested region of the deposit. A stockpile of 14,400 lb U3O8 in uranium bearing solution was recovered to surface during the FFT, representing the initial ramp-up of a leach recovery curve. To calculate the proven mineral reserves, the recovery determined through computer modelling for Phase 1 was applied to the estimated in situ mass contacted during the FFT.

Gryphon Mineral Resource Statement, Effective Date August 7, 2018

Notes:

Gryphon Mineral Reserve Statement, Effective Date September 1, 2018

Notes:

The mineral reserve for Gryphon is estimated at 49.7 Mlb U3O8 (1.2 Mt grading at 1.8% U3O8) as summarized in the above table.

The mine design and mineral reserve estimate have been completed to a level appropriate for a PFS. The Gryphon block model did not include any measured mineral resource material. All mineral reserves were converted from indicated mineral resources and are classified as probable mineral reserves. The inferred mineral resources contained within the mine design are considered as waste.

Mining Operations

Phoenix

The uranium ISR process, as proposed for Phoenix, involves the preparation of an acidic mining solution in the process plant that is transferred to the injection solution handling system at the wellfield to cause the dissolution of uranium compounds from the targeted mineralized zone. The acidic solution will dissolve and mobilize the uranium, allowing the dissolved uranium to be pumped to the surface as uranium bearing solution (“UBS”). UBS is recovered from the wellfield and transferred to the nearby process plant for uranium precipitation, drying, and packaging.

Containment of the solution is a requirement in ISR operations to ensure recovery of the uranium and to minimize regional groundwater infiltration into the mineralized zone and associated dilution of the mining solution. For Phoenix, it is proposed that artificial ground freezing will be implemented around the perimeter of the mineralized zone creating a vertical hydraulic barrier between the ISR zone and the external natural hydrogeology. The freeze wall will be established by drilling a series of vertical cased holes from surface and keying them into the basement rock. Circulation of a low temperature brine solution in the holes will remove heat from the ground, freezing the natural groundwater, and establishing an impermeable frozen wall around the deposit.

Benefits of ISR operations relative to traditional mining methods generally include:

The Company’s evaluation of the ISR mining method at Phoenix, as detailed in the Wheeler Report, has identified several significant environmental and permitting advantages, particularly when compared to the impacts associated with conventional uranium mining in Canada. The proposed ISR mining operation for Phoenix is expected to produce a low tonnage of solid waste relative to conventional uranium mill tailings, generate very small volumes of waste rock, and has the potential for low volumes of treated water discharge to surface water bodies, as well as the potential to use the existing power grid to operate on a near zero carbon emissions basis.

The planned use of ground freezing to isolate the ISR operation, has the potential to streamline the mining process, minimize interaction with the environment, and facilitate controlled reclamation of the site at decommissioning.

Taken together, ISR mining at Phoenix has the potential to achieve a superior standard of environmental sustainability when compared to conventional mining and milling operations.

Gryphon

The planned mining method for Gryphon is conventional longhole stoping with backfill. Longhole stoping is a widely used conventional mining method applied in both the Canadian uranium industry as well as in the broader mining industry for the extraction of base metals, gold, and other commodities.

According to the planned approach, access to the Gryphon deposit will be established through two shafts. The primary shaft will provide for movement of personnel and supplies, ore/waste hoisting, and fresh air to the underground operations. The second shaft will be solely for exhaust air and secondary egress. Heated fresh air will be delivered via the production shaft, with return air exhausted up the ventilation shaft. Both shafts will be excavated through blind boring methods. Blind bored shafts have been selected for vertical access in favour of typical full-face shaft sinking with cover grouting or freeze curtain protection. Blind bored shafts offer more competitive costs and construction schedules, and a reduced risk profile while sinking through saturated ground conditions. A composite steel/concrete liner will be installed over the full length of the shaft and grouted into basement rock. The main mine dewatering system will consist of a clean water pumping system that will pump decanted water to surface via piping in the ventilation shaft.

Access from the production shaft to the mine workings will be via a single ramp located on the hangingwall. Stope overcut and undercut drifts will include 100% shotcrete coverage and 150 mm of ballast on the floor to reduce the potential for radiation exposure.

The mine has been divided into five mining blocks, E Zone, Lower D, Upper and Lower Main, and Upper SW. Each mining block will be mined from the bottom up. Ore will be truck hauled to a rockbreaker/grizzly station and hoisted to surface. The mine is expected to produce approximately 605 t/d of ore and an average of 330 t/d of waste rock during the steady state operating period.

The Gryphon PFS Update assumes that the ore will be hoisted to surface and transported to the McClean Lake mill for processing. A two-year ramp-up to full production is planned, with the full production rate set at 9 million pounds U3O8 per year. Processing at the McClean Lake mill will require the negotiation and execution of a toll milling agreement, which is not currently established, and will also require regulatory approvals, which have not been obtained.

Processing and Recovery

Phoenix

The uranium bearing solution from the Phoenix wellfield will be directed to a self-contained processing facility located adjacent to the wellfield. The process design was developed from the process plant testing campaigns, using UBS column leach test solution as feed.

In the process plant, the first step is removal of impurities such as iron and radium from the UBS as solids in the stage 1 (Fe/Ra) precipitation circuit. The stage 1 solids are placed as filter cake in totes on a storage pad, for shipment offsite. Next, the purified leach solution (“PLS”) feeds the stage 2 (YC) precipitation circuit, producing uranyl peroxide YC product solid, which is then dried and packaged for shipment.

The barren leach solution (“BLS”) from stage 2 (YC) precipitation feeds the effluent treatment (ET) circuit, comprised of three stages. The first ET stage (ET stage 1) is low pH neutralization, which precipitates most of the remaining radionuclides. The resulting solids are placed as filter cake in totes along with the process plant stage 1 (Fe/Ra) precipitation circuit cake product. The second stage (ET stage 2) is high pH neutralization, which removes most of the remaining dissolved solids, forming a waste solids stream composed mainly of gypsum. This is pumped as slurry to a disposal pond for consolidation. The third ET stage neutralization (ET stage 3) targets selenium removal and adjusts final pH to near neutral. A small selenium-bearing waste solids stream is blended with the gypsum waste for disposal.

The different types of chemical reagents will be stored, used, and managed to ensure worker and environmental safety, in accordance with standards developed by regulatory agencies and vendors.

Uranium recovery was estimated by evaluating the losses of the individual circuits and combining into an overall steady state recovery. The final mass balance recovery is estimated to be 96.5%, as shown in the following table:

Phoenix Process Plant Steady State Recovery

It is estimated that during the ramp-up period for production recovery will be lower, resulting in a Year 1 recovery of 93.4% and a life of mine (“LOM”) process plant recovery of 96.3%.

The majority of the Fe/Ra and ET losses end up in the process precipitate solids (“PPS”). Preliminary estimate for recovery of uranium from reprocessing the PPS is 90%. The recovery from the PPS potentially increases the overall Phoenix recovery by 2.7%. The LOM recovery is summarized in the following table:

Phoenix Life of Mine Recovery

Gryphon

The Gryphon PFS Update assumes that Gryphon ore will be transported to the McClean Lake mill for processing. The mill is currently processing material from the Cigar Lake mine; however, it has additional licensed processing capacity to a total annual production of up to 24 million pounds U3O8.

The mine plan for Gryphon aligns well with expected available capacity at the McClean Lake mill. Proposed Gryphon Deposit production scenarios do not exceed McClean Lake’s production capacity given certain assumptions regarding future production from the Cigar Lake mine. Gryphon ore is expected to be milled in parallel to Cigar Lake Phase 2 production, assumed in the Wheeler Report to be up to 15 million pounds U3O8 per year, allowing for Gryphon ore processing at a peak of 9 million pounds U3O8 per year.

Processing the Gryphon Deposit will require certain modifications to the McClean Lake mill. These modifications include expansion of the leaching circuit, the addition of a filtration system to complement the counter current decantation circuit capacity, the installation of an additional tailings thickener, and expansion of the acid plant. Various other upgrades will also be required throughout the mill to permit production at the full licensed capacity.

Infrastructure, Permitting and Compliance Activities

Phoenix Infrastructure

The Phoenix site layout is reasonably compact around the deposit, and working within the natural terrain where practical, to limit environmental disturbance. Modular or temporary facilities are planned where practical to reduce impact and simplify site closure. The camp is designed for 100 occupants and for expansion to 150 if and as needed.

Phoenix Indicative Site Plan

The site plan is organized into radiological areas for control purposes. The wellfield, plant and nearest ponds are designated site locations where radioactive materials may be used or stored. Unauthorized persons are prohibited from entering radiation areas. The camp and operations facilities south of the production area are deemed non-radiation areas. Non-Radiation areas are areas where no radioactive materials are used or stored. The main site road will form a tertiary barrier between the radiation and non-radiation areas.

The planned infrastructure includes a gravel road from Highway 914 to site and an electrical power line from existing SaskPower distribution. A new airstrip and domestic and construction waste management areas are also included in site infrastructure plans.

Water is drawn from Whitefish Lake to the east. Well water is also available, which will be used to prepare potable water in the treatment plant near the camp. Domestic wastewater is sent to a mechanical treatment plant which produces water usable in the wellfield, and solids that are disposed in the industrial landfill.

Phoenix Permitting and Compliance Activities

Environmental studies of the Phoenix ISR operation are significantly advanced. Baseline environmental data collection, technical assessments, plus extensive engagement and consultation with Indigenous and non-Indigenous interested parties have been completed with sufficient rigor to support development and submission of the Draft EIS, and associated technical documents, to the provincial and federal regulators in 2022. The draft EIS outlines the Company’s assessment of the potential effects, including applicable mitigation measures, of the proposed ISR uranium mine and processing plant planned for Wheeler River.

Based on the information and related evaluation and assessment of effects, results show that the ISR operation can be constructed, operated, and decommissioned in a manner that is not likely to cause significant residual adverse effects to the biophysical or human environments, on its own or cumulatively with existing and reasonably foreseeable developments. Importantly, the Phoenix FS designs and plans incorporate learnings and mitigation measures identified through the EA process.

See “Government Regulation – Environmental Assessments” for more information.

In addition to the EA process, Denison will be required to obtain construction and operations permits from the Saskatchewan Ministry of Environment and Licences from the CNSC. While some overlap between the EA process and licensing/permitting is possible, generally licensing and permitting is expected to be completed following the EA process.

Denison recognizes the importance of early engagement and has been developing relationships with key interested parties since 2016. Amongst Denison’s guiding principles is the utmost respect for Indigenous communities, Indigenous Rights, and traditional knowledge. Denison wishes to work in partnership to return meaningful benefits from the Wheeler River project to potentially impacted Rights holders, communities, and/or groups.

Denison understands the importance of protecting the area in which it is working, including the land, the water, the animals, the air and culture. Denison welcomes input from all interested parties through regulatory engagement and consultation. Processes have been established with and for interested parties to work directly with Denison to express comments (positive or negative) or recommendations regarding its activities so the input can be incorporated into project plans, designs, and decisions.

Since 2016, Denison has engaged with Interested Parties to develop meaningful relationships and facilitate a collaborative approach to engagement and the advancement of the Wheeler River Project. Denison has developed and implemented an engagement plan to guide and structure such engagement activities. Engagement activities for Interested Parties are tailored to comply with both federal and provincial regulatory legislation and, importantly, meet the expectations of the parties.

To support its engagement and consultation activities for the Wheeler River project, Denison has developed practices to (1) ensure that employment opportunities are established for residents from the communities of interest; (2) procure goods and services from suppliers from the communities of interest and/or Indigenous-owned suppliers, to support continued exploration and evaluation activities; (3) support important community-led activities related to wellness and/or the preservation of traditional knowledge; and (4) solicit input through engagement and consultation activities into aspects of project designs (for example, selection of mining methods, access road routing, and selection of preferred treated water discharge locations).

While the engagement to date has focused on the Phoenix Project, the activities are also generally relevant to the Gryphon Project. Engagement to date has been extensive, and Denison’s approach with respect to consultation has been thorough and responsive to the requests of the public, Indigenous groups, and regulatory agencies.

See “Environmental, Health, Safety & Sustainability Matters” for further details.

Gryphon

A conceptual layout of the plan view of the Gryphon site surface facilities shows the relative scale and nominal footprint size of major infrastructure items, including shafts, ore stockpile, waste rock storage, backfill plant, water treatment plant, water treatment and management ponds, fuel and propane storage, explosive storage and operations centre. It is assumed the Phoenix camp will be used during Gryphon mine development and production.

Gryphon Indicative Site Plan

Gryphon is approximately 3 km northwest of the Phoenix deposit. Access to the Gryphon site will be via a 2 km road extension from the Phoenix site development. It will also be accessible by the airstrip northeast of the Phoenix deposit. Production from the Gryphon site will be trucked to the existing McClean Lake mill to the northeast, via existing Provincial Highway 914, including approximately 50 km of new road between the McArthur River mine and the Cigar Lake mine.

Gryphon Permitting and Compliance Activities

Although the current EIS and licensing efforts are not focused on the Gryphon Project, significant baseline information has been gathered through the EA programs completed on the Wheeler River property. It is likely that additional and confirmatory baseline data collection will be required to complete the environmental approval process for the Gryphon Project. As a result of a change in Federal legislation in 2019, the Gryphon Project will undergo an EA to meet the requirements of the Saskatchewan Environmental Assessment Act; however, no Federal EA will be required.

Based on the existing understanding of the proposed Gryphon Project, there is no reason to assume the Gryphon Project could not successfully complete an environmental assessment which could be acceptable to the federal and provincial regulatory regimes and the Gryphon Project’s stakeholders.

Additional regulatory approvals will be similar to those of the Phoenix ISR operation, whereby a Provincial permit and a CNSC licence will be prerequisites ahead of Gryphon Project construction and operation. When Gryphon moves forward, while consultation for Phoenix is relevant, consultation specific to Gryphon will be undertaken.

The decommissioning and reclamation plan for Gryphon will need to be reviewed and developed in more detail as the Gryphon Project is advanced.

Phoenix Capital and Operating Costs and Economic Analysis

Capital Costs

The estimated initial capital cost of the Phoenix Project is $419.4 million expressed in first-quarter 2023 Canadian dollars. This estimate falls under the AACE International Recommended Practice No. 47R-11 Class 3 Classification Guideline, with an expected accuracy to be within -15%/+25% of the Phoenix Project’s final cost, including contingency. The costs include construction of the initial ground freezing plant and wells, the first phase of production wells, and the ISR process plant and infrastructure required for first production.

Additional pre-commitment costs of $67.4 million are necessary to advance the Phoenix Project definition for regulatory purposes, and specifically to support a licence to construct satisfying the Canadian Uranium Mines and Mills Regulations SOR/2000-206. Once a licence to construct has been obtained the Phoenix Project will be considered de-risked sufficiently to enable the final investment decision (“FID”). The pre-commitment work includes engineering advancement, additional testwork, early procurement items, grid power design and execution, and management of these activities. Some of this work is in progress.

Sustaining capital is estimated to be $234.1 million and considers expansion of the wellfield and ground freezing system, and development of the injection solution system as the wellfield advances, expansion of the gypsum storage pad and modification to the process plant to accommodate well remediation.

Phoenix Initial Capital Cost Estimate

Note: Figures may not sum due to rounding.

Operating Costs

The operating costs over the Phoenix LOM is estimated at $478.1 million. Average operating costs are estimated at $8.51/lb U3O8 (US$6.28/lb U3O8) produced. Operating costs during the first five years of production are expected to be $6.64 (US$4.90) per pound U3O8, benefitting from increased scale of operations and higher concentrations of uranium contained in recovered UBS. During the remaining years of production, operating costs are expected to be $13.69 (US$10.10) per pound U3O8.

Phoenix Operating Costs

Note: Figures may not sum due to rounding.

Economic Analysis

The financial evaluation of Phoenix generates positive before and after-tax results.

Phoenix Summary of Economic Results

Notes:

The financial analysis was carried out using a discounted cash flow methodology. Net annual cash flows were estimated to project yearly cash inflows (or revenues) and subtract projected cash outflows (such as capital and operating costs, royalties, and taxes). These annual cash flows were assumed to occur at mid-year and were discounted back to the date of FID to proceed with construction. Discounted cash flows were totalled to determine the NPV of the Phoenix Project at a discount rate of 8%.

The Phoenix Project is most sensitive to fluctuations in the U3O8 price and feed grades and less sensitive to changes in capital costs and least sensitive to changes in operating costs.

Gryphon Capital and Operating Costs and Economic Analysis

Capital Costs

The estimated initial capital cost for the Gryphon Project is $737.4 million, expressed in third-quarter 2022 Canadian dollars. Costs developed from first principles in the 2018 study were escalated by 36% based on the Chemical Engineering Plant Cost Index for equipment and materials. Labour, subcontract, equipment rental and contractor indirect costs were escalated by 10%, and other materials were escalated by 20%.

This estimate falls under the AACE International Recommended Practice No. 47R-11 Class 4 Classification Guideline, with an expected accuracy to be within -15% to -30% and +20% to +50% of Gryphon Project’s final cost including contingency. The costs include shaft construction, underground development and mobile equipment, and McClean Lake mill upgrades.

Gryphon Initial Capital Cost Estimate

Note: Figures may not sum due to rounding.

Additional pre-commitment costs of $56.5 million are estimated necessary to advance the Gryphon project definition for regulatory purposes, and specifically to support a licence to construct satisfying the Canadian Uranium Mines and Mills Regulations SOR/2000-206. Upon receipt of licence to construct, Gryphon will be considered de-risked sufficiently to enable the FID. The pre-commitment work includes a feasibility study, environmental assessment, engineering advancement, additional testwork, early procurement items, grid power design and execution, and management of these activities.

Sustaining capital is estimated to be $98.7 million and considers underground development, construction and equipment.

Operating Costs

The operating costs over the LOM is estimated at $843.2 million. Average operating costs are estimated at $17.27/lb U3O8 (US$12.75/lb U3O8) produced.

Gryphon Operating Costs

Note: Figures may not sum due to rounding.

Economic Analysis

The financial analysis was carried out using a discounted cash flow methodology. Net annual cash flows were estimated to project yearly cash inflows (or revenues) and subtract projected cash outflows (such as capital and operating costs, royalties, and taxes). These annual cash flows were assumed to occur at mid-year and were discounted back to the date of FID to proceed with construction. Discounted cash flows were totalled to determine the NPV of the Gryphon Project at a discount rate of 8%.

The financial evaluation of the Gryphon Project using the updated cost estimate generates positive before and after-tax results. The results show a base case after-tax NPV of $864.2 million at a 8% discount rate, an IRR of 37.6% and a payback period of 22 months.

The Gryphon Project is most sensitive to fluctuations in the U3O8 price and feed grades and less sensitive to changes in capital costs and least sensitive to changes in operating costs.

Current and Contemplated Exploration, Development, and Production Activities

Phoenix

The results of the Phoenix FS indicate that Denison’s proposed uranium project is technically feasible and economically viable under the assumptions presented in the Wheeler Report. The Phoenix FS is considered sufficiently reliable to guide Denison in a decision to advance to the next phase of project development through front-end engineering design and detailed design to advance Phoenix to a point where the project is de-risked sufficiently to enable the FID. This includes field and laboratory testing, front-end engineering and design, detailed design, and early commitments for long-lead items to enable design and planning.

Gryphon

Pursuant to the Wheeler Report, the qualified persons who have reviewed Gryphon have set out a recommended program to prepare the Gryphon project to be advanced to the feasibility study stage of analysis. This includes infill and delineation drilling to advance the understanding of geology, mineralization controls and mineral resource for the Gryphon deposit, further metallurgical test work to further validate the performance of processing Gryphon ore at the McClean Lake mill, geotechnical requirements and recommendations for further advancement of Gryphon in subsequent stages, feasibility hydrogeological testing at Gryphon, and the collection of additional environmental baseline information.

Waterbury Lake

The Waterbury Lake property interests are owned by the WLULP, which is a partnership between Denison (69.33%) and KWULP (30.65%), as limited partners, and WLUC (0.02%), as general partner. Denison holds a 60% interest in WLUC (KWULP, 40%) and, in aggregate, holds a 69.35% interest in the WLULP through its limited partner and general partner ownership interests (KWULP, 30.65%). Denison is operator of the project.

In November 2020, Denison completed a preliminary economic assessment for the project (the “Waterbury PEA”), as summarized and reported in the technical report entitled “Preliminary Economic Assessment for the Tthe Heldeth Túé (J Zone) Deposit, Waterbury Lake Property, Northern Saskatchewan, Canada” effective October 30, 2020 (the “Waterbury Report”).

The Waterbury Report, completed in accordance with NI 43-101 and filed on December 30, 2020, evaluates a THT ISR operation estimated to produce total mine production of 9.7 million pounds of U3O8 (177,664 tonnes at 2.49% U3O8) over an approximate six year mine-life with final processing occurring at Denison’s 22.5% owned McClean Lake mill with a base case pre-tax NPV of $177 million (8% discount rate), IRR of 39.1%, and initial capital expenditures of $111.6 million, excluding pre-construction evaluation and development costs. The base-case economic analysis assumes uranium sales are made at UxC’s forecasted annual “Composite Midpoint” spot price from the Q3 2020 Uranium Market Outlook, stated in constant dollars (from ~US$49/lb U3O8 to US$57/lb U3O8). The Waterbury PEA was prepared on a project (100% ownership) and pre-tax basis, as each WLULP partner is subject to different tax and other obligations.

This project description is based on the Waterbury Report, a copy of which is available on the Company’s website, under its profile on the SEDAR+ website at www.sedarplus.ca and on EDGAR at www.sec.gov/edgar.shtml. The conclusions, projections and estimates included in this description are subject to the qualifications, assumptions and exclusions set out in the Waterbury Report. The Waterbury Report is recommended to be read in its entirety for a more fulsome understanding of the technical aspects of the project.

Property Description, Location and Access

The Waterbury Lake property is located within the eastern part of the Athabasca Basin in Northern Saskatchewan, which is within Treaty 10, in Nuhenéné / Athabasca Denesųłiné territory, and within the Métis Homeland.

The Waterbury Lake project, as of December 31, 2023, is comprised of thirteen (13) mineral dispositions, covering 40,256 ha. and contains two deposits: the THT deposit and Huskie deposit. The deposits are located within the property near its eastern edge. All dispositions have sufficient approved assessment credits to maintain the ground in good standing until at least 2033.

The project dispositions are approximately 750 km by air north of Saskatoon and about 420 km by road north of the town of La Ronge. Points North Landing, a privately-owned service centre with accommodations and an airfield, is located near the eastern edge of the property. Several uranium deposits are located nearby including the Roughrider, McClean Lake, Midwest Main, and Midwest A deposits.

Location of the THT (formerly J Zone) and Huskie Deposits on the Waterbury Lake project

Any uranium produced from the Waterbury Lake property is subject to uranium mining royalties in Saskatchewan in accordance with Part III of The Crown Mineral Royalty Regulations. See “Government Regulation – Canadian Royalties”. Denison has a 2% net smelter return royalty on the portion of the project that it does not own. There are no other contractual royalties on the property.

There are no known environmental liabilities associated with the Waterbury Lake property, and there are no other significant factors and risks that may affect access, title, or the right or ability to perform work on the property.

History

Uranium exploration activities have been conducted over various portions of the Waterbury Lake mineral claims over the past 50 years. The current Waterbury Lake mineral claims were originally staked by Strathmore Minerals Corp. in 2004. Strathmore subsequently spun out its Canadian assets to Fission in 2007. On January 30, 2008, KWULP and Fission entered into an earn-in agreement for the Waterbury Lake property, pursuant to which Fission granted KWULP the exclusive rights to earn up to a 50% interest in the Waterbury Lake property by funding $14,000,000 of expenditures on or before January 30, 2011. Additionally, Fission retained an overriding royalty interest in the property of 2% of net smelter returns. On April 29, 2010, KWULP had fully funded its $14 million of expenditures and consequently earned a 50% interest in the property. Fission and KWULP subsequently formed the WLULP in December 2010 with each party owning an equal interest. In April 2011, Fission exercised a back-in option right and increased its interest in the WLULP to 60%.

Effective April 26, 2013, Denison acquired Fission and all of Fission’s rights and entitlements to the Waterbury Lake property, including the 2% net smelter returns royalty. Denison became manager of WLULP and operator of Waterbury Lake. KWULP has not funded spending programs of the WLULP since January 2014 and, as a result, Denison has increased its interest in the WLULP while KWULP has diluted.

The THT uranium deposit was discovered during the winter 2010 drill program. The second drill hole of the campaign, WAT10-063A, was an angled hole drilled from a peninsula extending into McMahon Lake. It intersected 10.5 metres of uranium mineralization grading 1.91% U3O8, including 1.0 metre grading 13.87% U3O8 as well as an additional four meters grading at 0.16% U3O8. Subsequent drilling led Fission to focus on a significant mineralized trend immediately adjacent to the southeastern boundary of disposition S-107370. The maiden mineral resource estimate for THT was issued by Fission in 2011.

Denison first discovered mineralization for the Huskie deposit in summer 2017 drill hole WAT17-466A, which intersected 9.10% U3O8 over 3.7 metres, including 16.78% U3O8 over 2 metres, from 306.5 to 310.2 metres depth. Further drilling in 2017 and 2018 resulted in a maiden mineral resource estimate in December 2018.

Geological Setting, Mineralization and Deposit Types

The Waterbury Lake property is located near the southeastern margin of the Athabasca Basin in the southwest part of the Churchill Structural Province of the Canadian Shield. The Athabasca Basin is a broad, closed, and elliptically shaped, cratonic basin with an area of 425 km east-west by 225 km north-south. The bedrock geology of the area consists of Archean and Paleoproterozoic gneisses unconformably overlain by flat-lying, unmetamorphosed sandstones and conglomerates of the mid-Proterozoic Athabasca Group.

The Waterbury Lake property is located near the transition zone between two prominent litho-structural domains within the Precambrian basement, the Mudjatik Domain to the west and the Wollaston Domain to the east. The Mudjatik Domain is characterized by elliptical domes of Archean granitoid orthogenesis separated by keels of metavolcanic and metasedimentary rocks, whereas the Wollaston Domain is characterized by tight to isoclinal, northeasterly trending, doubly plunging folds developed in Paleoproterozoic metasedimentary rocks of the Wollaston Supergroup, which overlie Archean granitoid orthogenesis identical to those of the Mudjatik Domain. The area is cut by a major northeast-striking fault system of Hudsonian Age. The faults occur predominantly in the basement rocks but often extend up into the Athabasca Group due to several periods of post-depositional movement.

The basement geology beneath the Waterbury Lake project is comprised of approximately northeast-trending corridors of metasediments wrapping around orthogneissic domes. Locally, within the Discovery Bay trend, an east-west trending corridor of metasediments bounded to the north and south by thick zones of orthogneiss that, based on interpretation of aeromagnetic images, may represent two large dome structures. The metasediments and the orthogneiss domes are interpreted to be Paleoproterozoic and Archean in age, respectively.

The THT deposit is hosted within an east-west trending faulted package of variably graphitic and pyritic metasediments bounded by orthogneiss to both the north and south. The metasedimentary assemblage, which ranges in thickness from 90 to 120 metres and is moderately steep dipping to the north consists of, from north to south, a roughly 50 metre thick pelitic gneiss underlain by a 20 metre thick graphitic pelitic gneiss, underlain by a 10 to 15 metre thick quartz-feldspar wedge, followed by a 20 metre thick graphitic pelitic gneiss, underlain by a 15 to 25 metre thick pelitic gneiss, then back into a footwall orthogneiss. There are discontinuous offsets at the unconformity that range from a few metres to as much as ten metres.

THT is currently defined by 268 drill holes intersecting uranium mineralization over a combined east-west strike length of up to 700 metres and a maximum north-south lateral width of 70 metres. The deposit trends roughly east-west (80°) in line with the metasedimentary corridor and cataclastic graphitic fault zone. A 45 metre east-west intermittently mineralized zone occurs in the target area formerly known as Highland, separating the THT deposit into two segments referred to as the eastern and western lenses which are defined over strike lengths of 260 and 318 metres, respectively. A thin zone of unconformity uranium mineralization lies to the north of the intermittently mineralized zone interpreted to represent a mineralized block that has been faulted and displaced northwards, referred to as the mid lens.

Mineralization thickness varies widely throughout the THT deposit and can range from tens of centimetres to over 19.5 metres in vertical thickness. In cross-section, THT mineralization is roughly trough-shaped with a relatively thick central zone that corresponds with the interpreted location of the cataclasite and rapidly tapers out to the north and south. Locally, a particularly high-grade (upwards of 40% U3O8) but often thin lens of mineralization is present along the southern boundary of the metasedimentary corridor, as seen in holes WAT10-066, WAT10-071, WAT10-091, and WAT10-103. Ten-metre step-out drill holes to the south from these high-grade holes have failed to intersect any mineralization, demonstrating the tight nature of mineralization.

Uranium mineralization at the THT deposit is generally found within several metres of the unconformity, at depths ranging from 195 to 230m below surface. Mineralization occurs in three distinct settings: (1) entirely hosted within the Athabasca sediments, (2) entirely within the metasedimentary gneisses or (3) straddling the boundary between them. A semi-continuous, thin zone of uranium mineralization has been intersected in occasional southern THT drill holes well below the main mineralized zone, separated by several meters of barren metasedimentary gneiss. This mineralized zone is informally termed the South-Side Lens and can host grades up to 3.70% U3O8, as seen in drill hole WAT11-142.

The Huskie deposit is entirely hosted within competent basement rocks below the sub-Athabasca unconformity primarily within a faulted, graphite-bearing pelitic gneiss (“graphitic gneiss”) which forms part of an east-west striking, northerly dipping package of metasedimentary rocks flanked to the north and south by granitic gneisses. The Athabasca Group sandstones that unconformably overlie the basement rocks are approximately 200 metres thick.

The deposit comprises three stacked, parallel lenses (Huskie 1, Huskie 2 and Huskie 3), which are conformable to the dominant foliation and fault planes within the east-west striking graphitic gneiss unit. The drilling to date suggests the grade, thickness, and number of lenses present is controlled by the presence of northeast striking faults that cross-cut the graphitic gneiss. The northeast striking faults identified at the Huskie deposit are interpreted to be part of the regional Midwest structure. The deposit occurs over a strike length of approximately 210 metres, dip length of approximately 215 metres and has a true thickness of approximately 30 metres (individual lenses vary in true thickness, typically from 1 metre to 7 metres). The deposit occurs at vertical depths ranging between 240 and 445 metres below surface and 40 to 245 metres below the sub-Athabasca unconformity. The high-grade mineralization within the lenses consists of massive to semi-massive uraninite (pitchblende) and bright yellow secondary uranium minerals occurring along fault or fracture planes, or as replacement along foliation planes. Lower grade mineralization is disseminated within highly altered rocks proximal to fault planes. The mineralization is intimately associated with hematite, which both occur central to a broad and pervasive alteration envelope of white clays, chlorite and silicification.

Exploration

With the exception of drilling and related work, exploration on the Waterbury Lake property has mostly been in the form of geophysical surveys. Airborne magnetic surveys have been flown property-wide and have been used to identify significant basement structures and to help map basement rock types. Airborne and ground-based EM surveys have also been carried out across the property to define conductive, likely graphitic basement structures that may be associated with uranium mineralization. Additionally, ground-based induced polarization (DC-IP) and gravity surveys have aimed to identify zones of low resistivity and negative gravity anomalies resulting from quartz dissolution and clay alteration.

A 16 line, 28.8 kilometre DCIP resistivity survey was completed during October 2018. The survey was designed to map the possible extension of the Midwest structure onto the Waterbury Lake property and to define possible drill targets for future testing.

The 2020 geophysical program consisted of 17.6 line kilometres of TEM surveying was completed on the WAT20-G1 grid. This survey defined a weak south-dipping conductor: Conductor ‘C’. The eastern extent of this conductor has poor amplitude and is interpreted to extend deeply into the basement. This interpretation aligns well with the results of drill hole WAT19-493, which was drilled, in 2019, in the GB Northeast area.

A small moving loop electromagnetic (“SML EM”) survey was initiated in the winter of 2022 to resolve conductive lithologies associated with the interpreted southwest extension of the Midwest structural corridor as it may trend on to the Waterbury project lands on disposition S-107359. Results of the initial survey lines showed that the conductivity associated with the Midwest corridor did not trend onto the Waterbury project lands, and the remainder of the survey was cancelled.

No significant geological mapping has been conducted on the Waterbury Lake property to date as the property is predominantly covered by a thick layer of Quaternary sediments resulting in poor outcrop exposure; however, several reconnaissance scale surface geochemical surveys have been undertaken on the Waterbury Lake property.

Drilling

The THT deposit is well defined, as 268 drill holes have intersected uranium mineralization over a combined east-west strike length of approximately 700 metres and a maximum north-south lateral width of 70 metres. The mineralization thickness varies from tens of centimetres to 19.5 metres and the mineralization is found within several metres of the unconformity at depths of 195 to 230 metres. The THT deposit has been drilled, on average, at 10 metre by 25 metre spacings across the deposit and in some cases a more dense drill spacing has been applied. The genesis and structural complexity of the deposit are well understood.

Aside from THT, target areas that have seen the most drilling are the GB Zone, Oban South, and GB Northeast. A brief summary of each of these target areas is found below:

GB Zone – Nine drill holes were completed during the winter of 2019 to follow up on basement-hosted mineralization discovered during the summer 2018 drilling program. The winter 2019 drill holes were oriented steeply to the northeast on an approximate 100 x 100 metre spacing to test the faulted graphitic basement sequence which dips steeply to the southwest. Basement-hosted mineralization was intersected in drill hole WAT19-480, highlighted by 0.15% U3O8 over 6.0 metres, including 0.26% U3O8 over 3.0 metres. Additional basement-hosted mineralized intercepts were obtained approximately 100 metres to the southeast of WAT19-480 in drill hole WAT19-486, highlighted by 0.25% U3O8 over 2.0 metres and 0.22% U3O8 over 1.5 metres.

Oban South – The target area at Oban South comprises the interpreted intersection of the east-west trending Oban South graphitic conductor and the north-northeast trending regional Midwest structure. Three drill holes were completed as an initial test of the geological concept. The drilling successfully identified a faulted graphitic unit within the basement, which was hydrothermally altered, and a broad zone of desilicification within the lower sandstone, which included 10 ppm uranium and over 100 ppm boron within the basal 12.5 metres of sandstone immediately overlying the unconformity.

GB Northeast – A single reconnaissance drill hole, WAT19-493, was completed in 2019 to test a coincident airborne electromagnetic conductor and magnetic low approximately 2.5 kilometres to the northeast of the GB Zone. The drill hole intersected moderately to locally strong sandstone alteration and an altered and faulted graphitic pelite unit immediately below the unconformity. Geochemical sampling returned up to 200 ppm uranium over 0.5 metres, associated with semibrittle graphitic faulting. In 2022, seven holes were completed at GB Northeast, where drilling on each fence identified structurally-controlled alteration potentially indicative of a uranium mineralizing system. The strength of the alteration increased as drilling advanced to the southwest, approaching an interpreted flexure in the conductive trend.

Hamilton Lake – In 2022, two holes were drilled at Hamilton Lake to test the edges of a broad, N-S trending resistivity anomaly defined from DC-IP resistivity data collected in 2016. No significant structure or alteration was encountered in the two holes drilled at Hamilton Lake.

Sampling, Analysis and Data Verification

For THT, drill core was split once geological logging, sample mark up and photographing were completed. All drill core samples were marked out and split at the splitting shack by employees, put into 5-gallon sample pails and sealed and transported to Points North, Saskatchewan only prior to shipment. The samples were then transported directly to SRC in Saskatoon, Saskatchewan by Marsh Expediting. All geochemical, assay and bulk density samples were split using a manual core splitter over the intervals noted in the sample booklet. Half of the core was placed in a plastic sample bag with the sample tag and taped closed with fibre tape. The other half of the core was returned to the core box in its original orientation for future reference. All drill core samples were evenly and symmetrically split in half in order to try and obtain the most representative sample possible. Mineralized core samples which occur in drill runs with less than 80% core recovery are flagged for review prior to the resource estimation process.

Recovery through the mineralized zone is generally good and assay samples are assumed to adequately represent in situ uranium content. SRC offers an ISO/IEC 17025:2005 accredited method for the determination of U3O8 weight % in geological samples. Rock samples are crushed to 60 % at -2 mm, and a 100-200g sub-sample is split out using a riffler. The sub-sample is further crushed to 90% at -106 microns using a standard puck and ring grinding mill. An aliquot of pulp is digested in a concentrated mixture of HNO3:HCl in a hot water bath for an hour before being diluted with deionized water. Samples are then analyzed by a Perkin Elmer ICP-OES instrument (models DV4300 or DV5300).

Drill core samples collected for bulk density measurements were first weighed as they are received and then submerged in deionized water and re-weighed. The samples are then dried until a constant weight is obtained. The sample is then coated with an impermeable layer of wax and weighed again while submersed in deionized water. Weights are entered into a database and the bulk density of the core waxed and un-waxed (immersion method) is calculated and recorded. Not all density samples had both density measurements recorded. Water temperature at the time of weighing is also recorded and used in the bulk density calculation. The detection limit for bulk density measurements by this method is 0.01 g/cm3.

Prior to the summer 2010 drill program, the only QAQC procedures implemented on drill core samples from the project were those performed internally by SRC. The in-house SRC QAQC procedures involve inserting one to two quality control samples of known value with each new batch of 40 geochemical samples. All of the reference materials used by SRC on the Waterbury project are certified and provided by CANMET Mining and Mineral Services. The SRC internal QAQC program continued through the 2013 drill program. Starting in the summer of 2010 and continuing into the 2013 drill program (discontinued after DDH WAT13-350), an internal QAQC program was designed by Fission to independently provide confidence in the core sample geochemical results provided by SRC. The internal QAQC sampling program determines analytical precision through the insertion of sample duplicates, accuracy through the insertion of materials of “known” composition (reference material) and checks for contamination by insertion of blanks. Blanks, reference standards and duplicates were inserted into the sample sequence including field duplicates (quarter core every 1 in 20 samples), prep and pulp duplicates (inserted by SRC every 1 in 20 samples) and blank samples (1 sample for every mineralized drill hole). Beginning in 2012 certified, internal reference standards were used in all holes drilled at Waterbury Lake, replacing the re-analysed low, medium and high-grade reference samples. The results of the QAQC programs indicate there are no issues with the drill core assay data. The data verification programs undertaken on the data collected from the Project support the geological interpretations, and the analytical and database quality, and therefore the data can support mineral resource estimation.

With respect to its work on the Huskie deposit, Denison has developed and documented several QA/QC procedures and protocols for all exploration projects which include the following components: (a) Determination of precision – achieved by regular insertion of duplicates for each stage of the process where a sample is taken or split; (b) Determination of accuracy – achieved by regular insertion of standards or materials of known composition; and (c) Checks for contamination – achieved by insertion of blanks.

SRC has a quality assurance program dedicated to active evaluation and continual improvement in the internal quality management system. The laboratory is accredited by the Standards Council of Canada as an ISO/IEC 17025 Laboratory for Mineral Analysis Testing and is also accredited ISO/IEC 17025:2005 for the analysis of U3O8. The laboratory is licensed by the CNSC for possession, transfer, import, export, use, and storage of designated nuclear substances by CNSC Licence Number 01784-5-24.74. As such, the laboratory is closely monitored and inspected by the CNSC for compliance.

All analyses are conducted by SRC, which has specialized in the field of uranium research and analysis for over 30 years. SRC is an independent laboratory, and no associate, employee, officer, or director of Denison is, or ever has been, involved in any aspect of sample preparation or analysis on samples from the THT or Huskie deposits.

The SRC uses a laboratory management system (“LMS”) for quality assurance. The LMS operates in accordance with ISO/IEC 17025:2005 (CAN-P-4E) “General Requirements for the Competence of Mineral Testing and Calibration Laboratories” and is also compliant to CAN-P-1579 “Guidelines for Mineral Analysis Testing Laboratories”. The laboratory continues to participate in proficiency testing programs organized by CANMET (CCRMP/PTP-MAL).

ISR Field Testing

In 2023, the Company completed an inaugural ISR field test program at THT on the Waterbury Lake property. The program included (i) the installation of an eight well ISR test pattern designed to collect an initial database of hydrogeological data, (ii) testing of a permeability enhancement technique, (iii) the completion of hydrogeologic test work, highlighted by the achievement of hydraulic conductivity values consistent with those from the Waterbury PEA, and (iv) the execution of an ion tracer test which established a 10 hour breakthrough time between the injection and extraction wells, while also demonstrating hydraulic control of the injected solution. Overall, the program successfully achieved each of its planned objectives.

Mineral Processing and Metallurgical Testing

A preliminary assessment of the mineralogical and leaching characteristics of a representative selection of drill core samples from the THT deposit was undertaken between July and December 2011 by Mineral Services Canada.

The study was based on a suite of 48 samples of mineralized material collected from thirty-two drill holes (2010 and 2011 programs). These were chosen to provide good spatial representation of the THT mineralization as well as representing a wide range of uranium content. The samples were derived from the half split core remaining after the initial geochemical / assay sampling process. All samples were submitted to SRC for comprehensive mineralogical analysis and preparation of thin sections for petrographic analysis. The results of mineralogical work were used, in conjunction with spatial considerations, to define suitable composite samples for preliminary leaching test work undertaken by the Saskatchewan Research Council’s Mining and Minerals Division (“SRCMD”).

Mineralogical analysis, utilizing XRD, quantitative mineralogical analysis (Q-Min), petrography and SEM-EDS analysis, determined that the most abundant uranium-bearing minerals in the THT deposit are uraninite and/or pitchblende, and coffinite. The gangue mineralogy is essentially comprised of various amounts of quartz, phyllosilicates (illite-sericite, chlorite, biotite, kaolinite) and (Fe, Ti)-oxides (hematite, goethite and anatase). Feldspars also occur in most samples and carbonates as well as a variety of sulphides are locally present. Ni-arsenides are recognized throughout the samples as well. The results of the mineralogical analyses identified five groupings of samples with ore mineralogies typically dominated by either uranium oxide or uranium silicate phases.

Preliminary acid leaching tests were undertaken by SRCMD on composite samples prepared from the sample set. Only the leaching time and rate of acid addition were considered in the tests while the other parameters (e.g. solid percentage in the slurry, temperature, pressure and agitation conditions) remained fixed. A total of five composite samples were defined based on spatial location. Acid leaching (H2SO4) was performed on each of the composite samples for 12 hours under atmospheric pressure and at a temperature of 55-65°C. Agitation was used to create adequate turbulence. Sodium Chlorate was used as the oxidant. The tests were undertaken on the assay lab rejects from XRD analyses that were ground to 90% passing 106 microns. The percentage of solids in the slurry was set at 50%. The only variables were the acid addition and leaching residence time. Two different H2SO4 dosages were used to create an initial leaching environment with 25 mSc/cm and 55 mSc/cm, respectively. Each composite sample was split into two subsamples labelled A and B. The A sample was used to test high acid addition with high initial conductivity and the B sample was used to test low acid addition with low initial conductivity. The preliminary acid leaching tests showed that maximum extraction rates of 97.6 % to 98.5 % U3O8 can be obtained (depending on the acid addition) within 4 to 8 hours of leaching time, and that the leaching efficiency was variably affected by acid addition and leaching time.

Additional test work was undertaken in 2020. Leaching tests to determine key ISR data such as optimum reagent addition rates at lower leaching temperatures (10 to 20 degrees Celsius) and expected UBS head grade were conducted and the outcomes were used to drive reagent quantities.

A new composite THT east pod metallurgical testing sample was generated from 33 individual assay reject samples stored at the SRC facilities in Saskatoon. The individual samples, distributed through the deposit, allowed for the preparation of a deposit representative sample. The composite sample assayed 2.72% U3O8. Acid leaching tests at 10 deg C, using hydrogen peroxide (H2O2) oxidant, with varying sulphuric acid (H2SO4) concentrations (100, 80, 60 and 40 g/L) showed that extraction rates of 90% U3O8 can be obtained within 2 hours of leaching time, and that the leaching efficiency was affected by acid addition.

Mineral Resource Estimates

The Mineral Resources for the Waterbury Lake Project comprise the THT and the Huskie deposits. The Mineral Resource Statement presented herein represents the Mineral Resource evaluation prepared for the Waterbury Lake Project in accordance with NI 43-101.

Tthe Heldeth Túé Deposit

The THT deposit is estimated to contain an indicated mineral resource, using a base case cut-off grade of 0.10% U3O8, totaling 12,810,000 lbs based on 291,000 tonnes at an average grade of 2.00% U3O8 (100% basis). A range of mineral resources at various U3O8 cut-off grades (COG) has been estimated for THT. The current indicated mineral resource is stated using a grade cut-off of 0.10% U3O8.

For the 2013 mineral resource estimate, a 3D wireframe model was constructed based generally on a cut-off grade of 0.03 to 0.05 % U3O8 which involved visually interpreting mineralized zones from cross sections using histograms of U3O8. 3D rings of mineralized intersections were created on each cross section and these were tied together to create a continuous wireframe solid model in Gemcom GEMS 6.5 software. The modeling exercise provided broad controls on the size and shape of the mineralized volume. Inverse distance squared interpolation restricted to a mineralized domain was used to estimate tonnes, density and U3O8 grades as well as gold, arsenic, cobalt, copper, molybdenum and nickel grades into the block model.

Two passes were used to interpolate all of the blocks in the wireframe, but 99% of the blocks were filled by the first pass. The size of the search ellipse, in the X, Y, and Z direction, used to interpolate grade into the resource blocks is based on 3D semi-variography analysis (completed in GEMS) of mineralized points within the resource model. For the first pass, the search ellipse was set at 25 x 15 x 15 metres in the X, Y, and Z directions, respectively. For the second pass, the search ellipse was set at 50 x 30 x 30 metres in the X, Y and Z directions, respectively. The Principal azimuth is oriented at 75º, the principal dip is oriented at 0° and the Intermediate azimuth is oriented at 0°.

Huskie Deposit

The Huskie Deposit is currently estimated to contain an inferred mineral resource, using a base case cut-of-grade of 0.10% U3O8, totaling 5,687,000 lbs U3O8 based on 268,000 tonnes at an average grade of 0.96% U3O8 (100% basis). The Huskie Deposit resource estimate was prepared by Denison and independently audited and verified to confirm that the mineral resources were estimated in accordance with the widely accepted CIM Estimation of Mineral Resource and Mineral Reserve Best Practices Guidelines. The mineral resources may be affected by further infill and exploration drilling that may result in increases or decreases in subsequent mineral resource estimates. The mineral resources may also be affected by subsequent assessments of mining, environmental, processing, permitting, taxation, socio-economic, and other factors.

For the 2018 mineral resource estimate, GEOVIA GEMS™ software (version 6.8) was used to build three-dimensional mineralized wireframes for the Huskie 1, Huskie 2 and Huskie 3 lenses based on lithological and structural data from core logs and geochemical assay (or radiometric probe) data collected from 28 holes totaling 12,273 metres completed by Denison. A lower cut-off of 0.05% U3O8 and a minimum thickness of 1 metre was selected for the mineralized wireframe model.

The mineral resource model was constrained by the mineralization wireframes. The assay database (% U3O8 or % eU3O8) used for resource modelling consists of 201 assays from the 10 mineralized boreholes, contained within the three mineralized lenses. The 0.5 metre interval assays were composited to 1.0 metre lengths. Capping was considered, with only assay data from Huskie 2 being capped for % U3O8. Density values were assigned to the database based on a regression between U3O8 and density data pairs using the relationship determined for Denison’s Gryphon deposit, which is also hosted within comparable basement rocks. The validity of the Gryphon grade:density regression for the Huskie deposit was confirmed by plotting 12 bulk dry density samples collected by the technical report authors from the Huskie deposit. Variograms were modelled to determine appropriate search radii for grade estimation.

An accumulation-like approach was used, wherein “U3O8*density” and “density” were estimated into a three-dimensional block model, constrained by wireframes in two passes using ID2. A %U3O8 grade was then calculated into each block by dividing the estimated U3O8*density by the estimated density. A block size of 10 by 5 by 5 metres was selected. Search radii were based primarily on visual observations and variogram analyses. The estimation of U3O8*density and density were based on two estimation passes. The block model was validated using nearest neighbour estimation and by visual inspection of the block grades relative to composites and swath plots comparing the ID2 and nearest neighbour model. All blocks were classified as Inferred.

No pre-feasibility or feasibility studies have been completed to allow conversion of the mineral resources to mineral reserves. Consequently, no mineral reserves exist for the Waterbury Lake property at the present time.

Mining Operations

The THT deposit is proposed to be mined using the ISR method. The Indicated Mineral Resource used for the Waterbury PEA mine plan includes only the THT East pod, estimated at 9.7 million pounds of U3O8 with an average grade of 2.49% over 178,000 tonnes.

A small percentage of the THT East pod resource has not been included in the mine plan due to sterilization by freeze methods. Due to the geometry of the deposit and the nature of freeze technology applied to the deposit to allow for sufficient containment of mining fluid, the extreme western and easternmost portions of the deposit have not been considered in the Potentially Recoverable Resource. The collective resource attributed to sterilization is 206,180 lbs, representing 1.7% of the THT East pod.

Additionally, an 85% mining recovery factor was applied to the projected resource available for mining to account for sweep efficiencies and metallurgical recovery envisioned and deemed appropriate for the nature of the THT deposit. The mining recovery factor is a product of the metallurgical recovery and sweep efficiencies based on knowledge gained during the project development of the Phoenix deposit utilizing the ISR method. The sweep efficiency is defined as the percentage of mineralized rock in contact with the lixiviant as it circulates between the injection wells and surrounding recovery wells. The metallurgical recovery is determined by the amount and rate at which the uranium dissolves from the rock when in contact with the lixiviant.

Tthe Heldeth Túé East Pod Projected Mine Production (0% Grade cut-off (1))

The foregoing is based upon estimated indicated mineral resources. Mineral resources that are not mineral reserves do not have demonstrated economic viability.

A key hydrologic property that affects ISR mining is the permeability (hydraulic conductivity) of the ore zone and, just as importantly, the hydraulic communication (interconnectedness of the permeability/porosity) across the ore zone. The ability to transmit fluids through the ore body via well injection and recovery is fundamental to the efficacy of ISR mining.

Denison has performed permeameter testing of exploratory boring cores that were recovered from the ore zone and overlying and underlying strata at the site. The permeameter testing was conducted utilizing a portable nitrogen gas probe permeameter adapted for testing drill core pieces. Permeameter testing measures the matrix permeability of the core sample. Permeameter testing was performed by applying an epoxy ring at the sample location and sealing the permeameter probe against the ring to ensure a tight seal. Pressure is measured upstream of the probe tip at a sampling interval of two seconds, and the pressure decay of the nitrogen gas injection is measured to determine permeability in the drillcore at the sample location. In general, the gas pressure pulse applied to the drillcore is approximately 30 to 50 psi, and test durations are less than 20 minutes per test. This methodology was applied extensively at the Phoenix project, with testing conducted on core at approximate 10 centimeter intervals, resulting in a total of over 1,200 measurements.

Permeameter test results were reported for 150 core sample measurements in the THT East pod. Of the 150 measurements, 25 were from core collected within the mineralized zone, 43 were from the overlying Athabasca Sandstones, with the remainder from the underlying metasedimentary basement. The samples were further grouped into lithologic units.

Given the positive correlation between bulk hydraulic conductivity testing and permeameter testing of core samples in estimating hydraulic conductivity at the Phoenix deposit at Wheeler River, it is reasonable to assume a similar correlation for the THT deposit based on a comparable geologic setting. The recently conducted permeameter testing from the THT deposit should provide a reasonable initial estimate of hydraulic conductivity, although, the degraded state of the core most likely biased the tested samples toward lower permeabilities. Based on the currently available data, the hydraulic conductivity estimated from the THT permeameter testing appears to be notably lower than what was estimated for the Phoenix Project.

Several factors should be considered in the evaluation of permeability and its potential impacts to ISR mining applied to the THT deposit. First, as previously indicated, the samples suitable for conducting the permeameter testing are biased toward the more dense and intact (and likely lower permeability) core material. Second, the inter-well spacing (distance between wells within a well pattern) planned for the project will be less than what is proposed for the Wheeler River project at the Phoenix deposit, which will reduce the residence time for lixiviant to move from injection well to extraction well. Third, application of permeability enhancement methods will be utilized to increase the near well-bore permeability within the mineralized zone.

In conventional ISR operations, containment of the mining solution is typically achieved by natural impermeable bounding layers in the geological strata and/or by creating a natural drawdown (via pumping) of the water table towards the ore zone. At the THT deposit, there is a natural impermeable layer below the deposit, in the form of a competent package of basement rocks, but the deposit is otherwise hydraulically connected to the vast regional groundwater system in the overlying sandstone formation that defines the Athabasca Basin.

In order to maintain containment, the entire deposit will be isolated by use of an artificial and impermeable freeze wall that will surround the deposit. The freeze wall will be established by drilling a series of cased holes from surface and along the perimeter of the deposit, and keyed into the basement rock. The freeze wall will be comprised of 92 holes planned at a 7 metre spacing at the target depth of 200 metres and extend 30 metres below the unconformity elevation. The freeze wall is planned to be drilled entirely from land on the peninsula on McMahon Lake which extends to the eastern portion of THT. Freeze holes will be angled out to surround the mining zone with the minimum drilling angle limited to 45º to reduce technical risk of drilling and installing the freeze holes. Circulation of a low temperature brine solution in the holes will remove heat from the ground, freezing the natural groundwater, and establishing an impermeable frozen wall around the deposit.

The wellfield design included in the Waterbury PEA uses 184 wells at 7 metre spacing arranged in a 5-spot pattern, with four injection wells around one recovery well. The wells will be drilled from surface within the freeze wall and angled out to penetrate the mineralized zone at depth with a roughly 7 metre spacing.

Eight MWs will be installed outside of the freeze wall to detect and remediate any excursion of lixiviant from the mining zone.

Processing and Recovery Operations

Final mineral processing of the UBS expected to be recovered from the THT deposit is assumed to occur at the nearby McClean Lake mill. The mill is owned by the MLJV of which Orano Canada holds a 77.5% interest, and Denison Mines Inc. (a wholly-owned subsidiary of Denison) holds a 22.5% interest. The mill is currently processing material from the Cigar Lake mine under a toll milling agreement (up to 18 million lbs U3O8 per year); however, it has approximately 6 million lbs U3O8 per year in additional licenced processing capacity, with a total licensed capacity of up to 24 million lbs U3O8 per year. The Waterbury PEA assumes a recovery rate of 98.5% from the processing of UBS from the THT deposit at the McClean Lake mill.

It is assumed that the UBS will be transported to McClean Lake in trucks utilizing specifically designed tanks for transportation. The trucks would return with necessary lixiviant to complete ISR mining at THT. The McClean Lake Mill is assumed to have all necessary infrastructure to process the UBS and provide the lixiviant except for the facilities to provide surge storage of UBS and lixiviant at both the THT site and at McClean Lake.

The limited metallurgical testing of the THT deposit and other reviews indicate that a UBS head grade of 7 g/l may be possible through enhanced permeability techniques commercially available. The metallurgical tests completed during the Waterbury PEA indicate that approximately 27,000 tonnes of sulphuric acid will be required to leach the approximate 10 million lbs of U3O8 located within the THT East pod. Approximately 9,000 tonnes of hydrogen peroxide will be required. Lixiviant concentrations of 35 g/L hydrogen peroxide and 100 g/L of sulphuric acid have been estimated from metallurgical leach tests. Currently available data from metallurgical leach tests indicate no iron needs be added to the lixiviant.

Processing THT at the McClean Lake mill would require minor mill modifications. THT UBS, trucked to the mill, would be stored in a tank or pond, providing surge capacity for both the mine and mill. From the UBS storage it would be pumped into the mill leach circuit. The McClean mill may find it advantageous to mix the UBS into their leaching process to take advantage of the low pH, reducing acid addition rates for their other feed streams. Following CCD solution clarification, the solution would be processed as per the current mill flowsheet.

Toll milling agreement terms have not been assessed as part of this study. UBS from the THT deposit at a production rate 2.1 million lbs of U3O8/yr will make up a small portion of the entire McClean Lake mill feed (estimated in the range of 10 to 15%). Final drummed “yellowcake” will be a blend of the entire feed stream through McClean. The THT deposit is a relatively clean ore feed source in comparison to either Cigar Lake or the Midwest deposits both of which have contaminates of concern, that could result in penalties at the refinery. The scope of this study has not considered what other ores will be co-milled with the THT UBS, and therefore the final product make-up cannot be determined.

Infrastructure, Permitting and Compliance Activities

The THT site infrastructure has been modelled after the Wheeler River Phoenix infrastructure scaled appropriately for the requirements of the THT project.

Main land access to the site is from Saskatchewan Highway 905, via a road developed by Rio Tinto for Roughrider exploration requirements (with that project subsequently acquired by Uranium Energy Corp.). A road extension of 1.5 km will be required to access the ISR wellfield. Additionally, the existing road has been assumed to be upgraded from highway 905 to facilitate trucking of UBS and lixiviant.

The planned surface infrastructure at the THT site includes ISR wellfield and header houses, freeze plant, special and clean waste pads, UBS and lixiviant transportation pump stations for loading and unloading transport trucks, UBS storage pond, lixiviant solution storage pond, contaminated landfill, operations center (with potable water, fire suppression, and septic), electrical distribution, wash bay, warehouse, shop, propane and fuel storage tanks, and operational waste water management pond.

Due to the initial capital costs required to install a standalone processing plant at THT, processing of the THT deposit is expected to occur at the McClean Lake mill with the UBS being transported via trucks from the THT site to McClean Lake on the existing provincial road (45 kilometre one way). The trucks would complete the return trip to THT loaded with lixiviant.

Electrical power has been chosen for the PEA to be fed from a substation located approximately 13 km from the THT Site. Power has been assumed to be brought to site at 25 kV. A tradeoff study was completed as part of this study to compare line power to power generated at site, the conclusion of which favored line power. Additional work studying transmission and distribution options is required should further studies be completed.

At this stage, no environmental fatal flaws have been identified for the project. Through project design and implementation of various best management practices, project effects on the environment are expected to be avoided or minimized while meeting all applicable environmental guidelines and regulations. Given the proximity of the project to a surface waterbody it is likely that the most significant public concern will be the potential impacts to the lake, and it will be imperative for Denison to demonstrate how the groundwater and surface water environments will remain protected. The project will require completion of a provincial environmental assessment and federal licensing which includes the review of the environmental assessment to support a licensing decision. The approval process is anticipated to take 24 months following the submission of the draft licensing and environmental impact assessment documents.

Denison recognizes the importance of early identification of Interested Parties, and in particular, Indigenous and non-Indigenous Communities of Interest who may have an interest in the THT project based on historical and / or contemporary land use activities, known and asserted traditional territories, and / or historical precedent with the uranium industry in the eastern Athabasca Basin region. As noted above, also of importance is the strong interest most Interested Parties hold with respect to the protection of water, further underscoring the need for a proper and complete engagement strategy. As part of this process, Denison has identified a number of potential Communities of Interest for the THT project and can begin the process of suitable and appropriate engagement for the stage of the development of the THT project. This will assist Denison to determine the number and scale of Impact Benefit Agreements, which are often an important element as part of advancing a resource extraction project through the regulatory process in Canada.

Capital and Operating

The capital costs for the THT project were estimated relying on available data from the Wheeler PFS Report and the 2016 NI 43-101 Cigar Lake Operation Technical Report, as well as based on quotes and first principles estimates. The initial capital investment is estimated at $111.6 million, sustaining capital at $24.8 million and decommissioning costs at $25.2 million. The initial CAPEX includes a 30% contingency and excludes $20.1 million of project evaluation costs that must be incurred prior to construction. These costs should be considered when assessing the merit of advancing the project to a development decision in the future. The THT capital costs are outlined as follows:

The operating costs for the THT project were estimated relying on available data from the Wheeler PFS Report as well as historical milling cost from the MLJV for Toll Milling fees estimates, as well as first principal estimates. The total operating costs are estimated at $155.7 million ($16.27 per lb of produced U3O8).

The THT ISR operation is estimated to produce total mine production of 9.7 million pounds U3O8 over an approximate six year mine-life with final processing occurring at Denison’s 22.5% owned McClean Lake mill.

Each WLULP partner reports its share of the operations in its own tax return. As each partner has a unique tax profile, the THT project has been evaluated using two different cash flow model approaches:

The calendar years referred to in the economic model developed for the Project are indicative only and should not be understood as reflecting the Company’s plans for advancing the project.  Any advancement of the Project, or the timing thereof, is subject to various factors, some of which may be outside of the Company’s control.  The Company has advised that it will provide additional applicable guidance on its intentions to advance the Project in its public disclosure, as appropriate.

Inputs and assumptions to both the pre-tax and post-tax cash flow models include:

The pre-tax base case cash flow model is based on the inputs noted above and the following additional notes:

The THT project economic results are quite sensitive to the price of uranium. To illustrate the impact on the project from lower and higher uranium price assumptions than those in the pre-tax base case, the PEA considers an additional two pricing scenarios: (1) the Low Case, which uses an estimated fixed uranium selling price of US$35.00/lb U3O8 for all production; and (2) a High Case, which uses an estimated fixed uranium selling price of US$65.00/lb U3O8 for all production.

A summary of the economic results of the pre-tax low, base and high case scenarios are illustrated in the table below.

Pre-tax Economic Results (100% basis) Summary – Low, Base and High Case

The post-tax base case cash flow model is specific to Denison’s ownership interest in Waterbury Lake and Denison’s specific facts and circumstances, including:

Discounting for NPV calculations remains at 8% (refer to Section 22.5.1 of Waterbury PEA for additional information), and the impact of estimated net smelter royalties of $3.8 million owing to Denison on KWULP’s share of THT production has not been included (refer to Section 4.5 of Waterbury PEA for additional information).

A summary of the economic results of the post-tax low, base and high case scenarios reported in the PEA are illustrated in the table below.

Denison, through Denison Waterbury Corp, currently has a 69.35% aggregate ownership interest in the WLULP. At the date of the PEA, Denison’s ownership interest was 66.90%. The post-tax modeling has not been updated for Denison’s increased ownership position. 

Post tax Economic Results (Denison’s Share(1)) Summary - Low, Base and High Case

The PEA is a preliminary analysis of the potential viability of the project’s mineral resources, and should not be considered the same as a Pre-Feasibility or Feasibility Study, as various factors are preliminary in nature. There is no certainty that the results from the PEA will be realized. Mineral resources are not mineral reserves and do not have demonstrated economic viability.

McClean Lake

The McClean Lake projects are owned by Denison (22.5%) and Orano Canada (77.5%). Orano Canada is the operator/manager of the projects.

Except as otherwise noted below, the project descriptions are based on the Company’s technical reports: (A) the “Technical Report on the Denison Mines Inc. Uranium Properties, Saskatchewan, Canada” dated November 21, 2005, as revised February 16, 2006 (the “McClean Technical Report”), (B) the “Technical Report on the Sue D Uranium Deposit Mineral Resource Estimate, Saskatchewan, Canada” dated March 31, 2006 (the “Sue D Report”), and (C) the “Technical Report on the Mineral Resource Estimate for the McClean North Uranium Deposits, Saskatchewan” dated January 31, 2007 (the “McClean North Technical Report”), copies of which are available on the Company’s website and under its profile on the SEDAR+ website at www.sedarplus.ca. Scott Wilson RPA (since acquired by SLR) was engaged to prepare and deliver the McClean Technical Report (authored by Richard E. Routledge, M.Sc., P.Geo.), the Sue D Report and the McClean North Technical Report (each authored by Richard E. Routledge, M.Sc., P.Geo. and James W. Hendry, P.Eng.). Each author was an independent Qualified Persons for the purposes of NI 43-101. By letter dated October 20, 2009, Orano Canada received from Scott Wilson RPA subsequent corrections to the resource estimate in the McClean North Technical Report, which revisions have been incorporated herein as applicable.

The conclusions, projections and estimates included in this description are subject to the qualifications, assumptions and exclusions set out in the technical reports. The reports are recommended to be read in their entirety for a more fulsome understanding of the technical aspects of the projects.

Property Description, Location and Access

The McClean Lake property is located within the eastern part of the Athabasca Basin in northern Saskatchewan, approximately 26 kilometres west of the Rabbit Lake mine and approximately 750 kilometres north of Saskatoon. Access to the McClean Lake site is by both road and air. Goods are transported to the site by truck over an all–weather road connecting with the provincial highway system. Air transportation is provided through the Points North airstrip about 25 kilometres from the project site.

The mineral property consists of four (4) mineral leases covering an area of 1,147 hectares and 13 mineral claims covering an area of 3,111 hectares. The right to mine the McClean Lake deposits was acquired under these mineral leases, as renewed from time to time. Mineral leases are for terms of 10 years with the right to renew for successive 10-year periods provided that the leaseholders are not in default of the terms of the lease. A mineral claim grants the holder the right to explore for minerals within the claim lands and the right to apply for a mineral lease. The current mineral leases have terms that expire between November 2025 and August 2026 and title to the mineral claims is secure until at least 2041. It is expected that the leases will be renewed in the normal course, as required, to enable all the McClean Lake deposits to be fully exploited.

The right to use and occupy the lands at McClean Lake has been granted in a surface lease agreement with the province of Saskatchewan. The McClean surface lease was entered into in 2002, has a term until 2035 (33 years) and covers a land area of approximately 3,677 hectares.

The uranium produced from the McClean Lake deposits is subject to uranium mining royalties in Saskatchewan in accordance with Part III of The Crown Mineral Royalty Regulations. See “Government Regulation - Canadian Royalties.” In addition, a royalty of 2% of the spot market price on all U3O8 produced from the Sue E deposit is payable to the previous owner of a portion of the deposit.

History

Several operators and related joint ventures have managed the McClean Lake project from 1968 to present. Their involvement has resulted in the discovery of several uranium deposits including McClean North, McClean South, JEB, Sue trend (A,B,C,D,E) and Caribou. Exploration activities over the project have involved extensive geophysical surveys, both airborne and ground, in addition to exploration/delineation diamond drilling.

Uranium production from the McClean Lake deposits at the onsite McClean mill facility to date (current to 2021) is approximately 50 million pounds U3O8. The ore feed for production is almost entirely sourced from mining activities of the Sue (A, B, C, and E) and JEB deposits.

1968 – 1974 (Gulf Minerals Canada Ltd.)

From 1968 to 1974, the entire area was held under permit (Permit #8) by Gulf Minerals Canada Ltd. During this period, Gulf flew an airborne radiometric survey over the area and conducted reconnaissance and ground level surveys.

1974 – 1985 (Canadian Occidental Petroleum Ltd.)

In 1974 Gulf reduced their land holding and allowed Permit #8 to lapse. Canadian Occidental Petroleum Ltd. (“CanOxy”) acquired the ground and flew a reconnaissance survey over the area in July of that same year and staked a 260 square kilometre area called then the Wolly property (now divided into the McClean Lake and Wolly properties). CanOxy operated the project from 1974 to 1985 at first without partners, then in 1977, in partnership with Inco Ltd.

Initial exploration consisted of geochemical and ground radiometric prospecting with follow up drilling. Several geophysical methods were also used, but correlation with geochemical and radiometric anomalies was generally poor. In 1977, airborne magnetic and EM surveys were flown over the property. The results indicated conductive trends and helped to better define the regional basement structure and lithology. The first significant discovery came in 1978, when the Tent Lake zone was found along a major conductive trend. Following this discovery, the emphasis was on geophysical rather than geochemical or radiometric targets. From 1979 to 1985, several major discoveries were made based mainly on geophysics and improved geological interpretations. This included the McClean North deposit in 1979, the McClean South deposit in 1980, the Candy Lake zone in 1981 and the JEB deposit in 1982. During this period, CanOxy completed 781 drill holes for 118,540 metres of drilling; most of them concentrated in the area now known as the McClean Lake property.

CanOxy prepared estimates of tonnages, grades and contained uranium for McClean Southeast and Southwest deposits as of 1980, which have not been verified by Denison. The results of these estimates are set out below. The Company is not treating this historical estimate as current mineral resources or mineral reserves.

1985 – 2020 (Minatco / Denison Mines / OURD)

In January 1985, Minatco entered into a joint venture agreement with CanOxy and Inco to become the operator of the project. Geophysical and drilling programs were conducted throughout the project area to follow up existing mineralized areas and explore new zones. In 1987, an additional zone (Pod 5) was found in McClean North. Several very significant discoveries were also made the following year, in 1988: two new mineralized zones, Sue A and B were found in the Sue area, which would lead to the discovery of the highly productive Sue trend; mineralization was indicated on the McClean South conductor, west of the McClean Southwest pod; and additional mineralization was found in McClean North. Additional work in the Sue area over the next few years, led to the Sue C deposit in 1989, the Sue D deposit in 1990 and the Sue E deposit in 1991. From 1985 to 1993, Minatco completed 1,160 drill holes for a total of 171,090 metres of drilling, most of them concentrated again in the area now known as the McClean Lake property.

In 1990, the CanOxy-Inco JV sold out to Minatco. In 1993, Denison Mines Ltd. exchanged with Minatco a 70% interest in the Midwest Lake project for a 22.5% interest in the McClean Lake project. OURD obtained a 7.5% interest. Orano Canada’s predecessor acquired the uranium assets of Minatco in Canada and became operator of the McClean Lake Project. The McClean Lake property was then created and defined as a portion of the Wolly property outlined by a surface lease (containing the JEB, Sue and McClean deposits).

2020 (Orano Canada / Denison)

In 2020, OURD sold its 7.5% interest in the MLJV to Orano Canada.

Geological Setting, Mineralization and Deposit Types

The McClean Lake uranium deposits lie near the eastern margin of the Athabasca Basin in the Churchill Structural Province of the Canadian Shield. The bedrock geology of the area consists of Precambrian gneisses unconformably overlain by flat lying, unmetamorphosed sandstones and conglomerates of the Athabasca Group. The Precambrian basement complex is composed of an overlying Aphebian aged supracrustal metasedimentary unit infolded into the older Archean gneisses. The younger Helikian aged, Athabasca sandstone was deposited onto this basement complex. The basement surface is marked by a paleoweathered zone with lateritic characteristics referred to as regolith.

The McClean Lake uranium deposits which include the Sue deposits (A to E), McClean deposits (North and South), Caribou deposit and JEB deposit are unconformity-related deposits of the unconformity-hosted variety.

Exploration and Drilling

Exploration activities including ground geophysics and diamond drilling were conducted by Orano Canada from 1994 to present. The majority of exploration has been focused on areas of known mineralization at McClean North/South, Sue Trend, JEB and the Tent Seal Trend. Other target areas on the property which have also been subject to ground geophysics and drilling include Candy Lake, Bena, Vulture and Moffat Lake. In 2002 the discovery of Caribou, the high- grade unconformity related uranium deposit was made approximately 2 kilometres northwest of the Sue C open pit. No other significant discoveries have been made since 2002. During the period 1994 to 2019 Orano Canada completed 98,498 metres of drilling in 505 holes, with no significant exploration conducted on the property in 2020.

The 2021 exploration program was designed to test for the potential expansion of previously discovered mineralization in the McClean South 8W and 8E pods, as well as to test for new mineralization in the surrounding area. Fifteen drill holes totaling 4,083 metres were completed during the 2021 program. Three of the final four drill holes completed by Orano Canada returned uranium mineralization at the McClean South target area, with the results highlighted by drill hole MCS-34, which returned 8.67% U3O8 over 13.5 metres (including 78.43% U3O8 over 1.1 metres), with a cut-off grade of 0.05% and true thickness estimated to be approximately 85%.

The 2022 exploration program focused on testing the extents of the high-grade mineralization discovered in the 2021 drill program at McClean South. 23 drill holes were drilled, totaling 5,862 metres. Ten of the 23 drill holes returned notable uranium mineralization, including drill hole MCS-58, which returned 2.96% U3O8 over 15.5 metres, including 24.49% U3O8 over 1.5 metres, located approximately 54 metres to the southeast of drill hole MCS-34. Overall, the results from 2022 have successfully expanded the footprint of the mineralized zone to approximately 180 metres in strike length. Additional evaluation drilling was conducted at the McClean North deposit. See “Denison Operations-SABRE Mining Program” for further details.

No exploration program was conducted in 2023 nor is planned for 2024.

Sampling, Analysis and Data Verification

The following description applies to all exploration on the McClean Lake property.

Following the completion of a drill hole, the hole is radiometrically logged using a downhole slim-line gamma probe. The gamma-log results provide an immediate equivalent uranium (“eU”) value for the hole, which, except in high-grade zones, is reasonably accurate. The gamma-log results, however, have not been used for the purposes of estimating mineral reserves or resources unless core loss is significant. Sample intervals are generally 50 centimetres long, except where higher or lower grade mineralization boundaries fall within the interval. In that case, two 25 centimetre samples are collected. Flank samples of 1.0 metre are always collected where mineralization is located. A background geochemistry sample is collected every 10 metres down the hole.

All sampled core is split in half, one half retained and the other sent to an independent laboratory. Lost core is not an issue at the McClean project as core recovery has been good. Control samples are routinely assayed with each batch of core samples analyzed.

The mineralization in the various McClean deposits is highly variable in both mineralogy and uranium content. The principal minerals identified in the deposits are pitchblende, uraninite and niccolite. As a result of the highly variable uranium content, a variable density formula was developed for the McClean deposits. This formula was modified over the years to account for the fact that it originally tended to underestimate U3O8 content where the U3O8 values were associated with high values of nickel and arsenic.

No opinion can be given regarding security of samples in the mid to late 1970s and the late 1980s other than to indicate that subsequent geological work and all metallurgical and geotechnical work have confirmed the results. All procedures reviewed follow generally accepted industry practice. A good demonstration of the reliability is that JEB and the Sue deposits (B and C) have been mined out and more uranium has been recovered into stockpiles than had been estimated from surface drilling.

Mineral Reserve and Mineral Resource Estimates

Estimation procedures have evolved over the years. At the time of the feasibility study in 1990, polygonal methods were used for the JEB, the Sue A, the Sue B, the Sue C deposits and for the McClean zones. Prior to the start of mining at the JEB deposit, the mineral reserves were re-evaluated using computerized methods whereby block models were constructed and geostatistical methods were implemented. Much more recently, these mineral resource estimates have been further refined using Whittle pit optimization software. Appropriate tests and audits of the databases on all the McClean deposits have been carried out by past qualified Denison personnel. In the case of JEB, Sue C and Sue B, the amount of U3O8 recovered into stockpiles was higher than that estimated from surface drilling.

The Company received the McClean Technical Report from Scott Wilson RPA (now SLR) on its mineral reserves and mineral resources at certain of the deposits (Sue A, B, E and McClean North and Caribou) at McClean Lake. See “Mineral Reserves and Mineral Resources”, above, for a summary of the mineral resource and mineral reserve estimates remaining, after adjusting for mining activity, as applicable.

In preparing the McClean Technical Report, Scott Wilson RPA reviewed previous estimates of mineral reserves and mineral resources at the applicable properties, and examined and analyzed data supporting the previous estimates, as well as other available data regarding the properties, including extensive information from Orano Canada.

For the Sue E deposit, Scott Wilson RPA constructed a block model using indicator kriging to both map out and geologically constrain mineralized areas. A block that had at least one nearby composite within 10 metres of its centre, and that had composites from at least two different drill holes in its search neighbourhood was classified as part of the indicated mineral resource. The indicated mineral resource was evaluated by Scott Wilson RPA in 2005 using Whittle economic evaluation software showing that the Sue E pit economics were robust and mineral reserves were estimated. Mining was completed at the Sue E pit during 2008 recovering about 91% of the probable mineral reserves estimated. Scott Wilson RPA classified approximately 7.3 million of the pounds outside the current pit as inferred mineral resources. Confirmatory drilling in 2006 by the operator has indicated that this may be reduced to 2.0 million pounds, but mineral resources have not been re-estimated.

The mineral resource estimate for the Caribou deposit is based on a block model for which grade was interpolated using ordinary kriging. Since there were no plans for the mining of this deposit at the date of the McClean Technical Report, the economic potential was not evaluated and mineral reserves were not estimated.

With respect to the Sue D deposit, the Company received the Sue D Report in 2006, authored by Scott Wilson RPA. Scott Wilson RPA carried out an independent mineral resource estimate for Sue D by conventional 3-D computer block modeling. A minimum vertical mining width of two metres was employed with a 0.1% U3O8 cut-off.

Due to the significant increase in the price of uranium from 2004 to 2006, Denison engaged Scott Wilson RPA to re-evaluate the uranium resources in the McClean North trend that are amenable to other methods of mining. The original McClean Technical Report had only evaluated mineral resources and mineral reserves of the high grade portions under the assumption that they would be mined using a blind shaft mining method. The McClean North Technical Report on the mineral reserves and resources at the McClean North uranium project was completed in 2007.

The re-evaluation of McClean North was carried out by conventional 3-D computer block modeling. Wire frames were constructed for each of pods 1, 2 and 5. The estimate included internal dilution, but not external dilution, and was carried out at a 0.1% U3O8 cut-off. This mineral resource estimate is based entirely on diamond drill information. Block cell dimensions were selected at 8 metre (easting) x 5 metre (northing) and a 2 metre bench height or approximately 180 tonnes/block. Scott Wilson RPA constructed a mineral resource wireframe based on kriging, and constructed a special waste wireframe, that generally surrounds the mineral resource wireframe, using similar kriging parameters but with larger search distances. Subsequent to this report, the Company and Scott Wilson RPA reviewed the block model and estimation procedures in October 2009 and made a slight revision to the mineral resource estimate for the McClean North deposit.

Mining Operations

McClean Lake consists of nine known ore deposits: JEB; Sue A, B, C, D and E; McClean North; McClean South; and Caribou. In 1995, the development of the McClean Lake project began. Mill construction commenced in 1995 and ore processing activities reached commercial production in November 1999. Mining operations also commenced, and the following deposits have been mined out to date: JEB (1996 to 1997), Sue C (1997 to 2002), Sue A (2005 to 2006), Sue E (2005 to 2008) and Sue B (2007 to 2008).

The remaining ore reserves consist of a limited quantity of stockpiled ore from historical Sue B open pit mining operations and SABRE test mining activities at McClean North. Approximately 87,454 tonnes of Sue B ore at a grade of 0.35% U3O8 and 2,481 tonnes of McClean Lake North ore (mined via SABRE, as defined below), at an average grade of 0.80% U3O8, are stockpiled on surface.

Low-grade special waste from the mining of the JEB, Sue C, Sue A, Sue E and Sue B deposits has been disposed of in the mined-out Sue C pit. In the future, Cigar Lake special waste is also expected to be disposed of in the Sue C Pit. By agreement between the CLJV and the MLJV, costs to update the Sue Water Treatment Plan and costs to dewater the Sue C pit for Cigar Lake special waste will be shared 50/50 between the CLJV and MLJV.

Since 2006, various test mining programs have also been conducted at McClean North. In 2023, Denison and Orano Canada approved a restart of uranium mining operations using the joint venture’s patented SABRE mining method. Mining is planned to commence at the McClean North deposit in 2025, with 2024 activities expected to focus on preparations necessary to ready the existing SABRE mining site and equipment for continuous commercial operations, as well as the installation of pilot holes for the first mining cavities planned for excavation. See “Denison Operations-SABRE Mining Program” for more information.

Processing and Recovery Operations

Processing of the McClean Lake ore stockpiles is anticipated to occur prior to the end of life of the McClean Lake mill. Historical processing of the McClean Lake orebodies through 2000 to 2010 has demonstrated strong performance, with recoveries above 97%. The MLJV anticipates processing of the remaining stockpiles to have similar performance results.