Mr. Phil Williams reports

ISOENERGY PROVIDES UPDATE ON ITS U.S. MINE RESTART PLANS WITH ADVANCEMENT OF THE TONY M MINE IN UTAH

IsoEnergy Ltd. has made a strategic decision to reopen access to the underground at its Tony M uranium mine in the first half of 2024 (H1 2024), with the goal of restarting uranium production operations in 2025, should market conditions continue as expected. The decision to advance Tony M is underpinned by rising uranium prices, the climate of increasing support and demand for nuclear energy, and the recent announcement by Energy Fuels Inc. (EFR) to restart its uranium circuit at the White Mesa mill, with which IsoEnergy has a toll milling agreement.

Tony M, along with the company's Daneros and Rim projects, is one of three past-producing, fully permitted uranium mines in Utah owned by IsoEnergy, and is a large-scale, fully developed and permitted underground mine that previously produced nearly one million pounds of U3O8 (triuranium octoxide) during two different periods of operation, from 1979 to 1984 and from 2007 to 2008.

Highlights:

• Reopening of the underground and comprehensive work program -- the company plans to reopen the main decline into the Tony M mine and gain underground access by the end of H1 2024. This critical step is expected to facilitate the assessment of the mine's underground conditions, enable direct analysis of the uranium mineralization in place, and allow for the collection of necessary data required to prepare an efficient mine plan. The work program also includes underground and surface geological mapping of the sandstone-hosted uranium and vanadium mineralization to allow for more precise extraction plans for inclusion in an updated economic study.
• Technical/economic study planned -- the company intends to complete a study, which will provide further details on a potential restart date and a mine plan that will provide production plans and rates, expected operational costs and capital requirements.
• Toll-milling arrangement with EFR -- IsoEnergy has a toll milling arrangement with EFR for its Tony M, Daneros, Rim and Calliham projects, which guarantees the company access to the White Mesa mill, the only operational conventional uranium mill in the United States. On Dec. 21, 2023, EFR announced its plans to restart the White Mesa mill uranium circuit in 2025. As a result, and to support additional feed, IsoEnergy intends to deliver ore to the mill in time for the restart of the uranium circuit.
• Commencement into multiasset production -- the reopening of the Tony M mine is a first step in IsoEnergy's plan to becoming a multiasset uranium producer. IsoEnergy is also evaluating plans to restart operations at the Daneros and Rim mines, both of which were previous producers of uranium and vanadium, and are currently permitted for production.
• Staffing up for reopening -- the company has appointed Josh Clelland to the position of director of United States engineering and operations, to manage the reopening of the Tony M mine and advancement of the company's other U.S.-based uranium projects. Mr. Clelland is a professional mining engineer with over 20 years of experience in the mining industry, including significant experience operating in both underground and open-pit environments. He joins the company from a major global gold producer where, in his most recent role, he was a superintendent of mine operations. Mr. Clelland's additional experience includes a corporate development role at a major producer, technical advisory at a major international mining consulting firm and research at a Canadian brokerage firm, during which time Mr. Clelland earned his chartered financial analyst designation.

Phil Williams, IsoEnergy's chief executive officer and director, stated: "With the uranium spot price now trading around $100 (U.S.) per pound, we are in the very fortunate position of owning multiple, past-producing, fully permitted uranium mines in the U.S. that we believe can be restarted quickly with relatively low capital costs. Our existing toll milling agreement with Energy Fuels places IsoEnergy in a unique position to become a conventional uranium producer in the near term.

"Multiple work streams are now under way to move our flagship Tony M mine back toward production in 2025, in line with the timing Energy Fuels has announced for its White Mesa mill, for which IsoEnergy has a toll milling agreement. Given current and expected near-term uranium market dynamics, we think this restart timing is ideal and would firmly place us in a very small group of uranium companies able to deliver uranium production in the near term. I would also like to welcome Josh to the team. We are fortunate to be able to attract such high-quality talent, which we believe is a testament to our projects and vision for the company."

Tony M mine work program

The company is continuing to advance plans to reopen the underground mine workings in preparation for a potential restart of Tony M. This work program includes updating mine ventilation and escape plans, maintenance of the existing ventilation fans and power infrastructure, surveying of the underground mine workings, rehabilitation of mine workings and ground support as needed, and upgrading and/or replacement of utilities.

Rehabilitation of the underground is expected to take place during H1 2024, followed by planned geologic mapping and sampling alongside mine planning ahead of anticipated completion of the study. The company currently expects to utilize contract mining initially. In addition to the 18 miles of underground development, including multiple production headings, the mine has complete surface infrastructure in place.

IsoEnergy continues to work with RME Consulting, a leading international, technical underground mining ventilation and refrigeration design firm, to oversee the design and implementation of the ventilation plan, and Call & Nicholas Inc., an international mining consulting firm that specializes in geological engineering, geotechnical engineering, and hydrogeology, to assess the mine's ground conditions.

IsoEnergy has guaranteed access to the White Mesa mill by way of a toll milling agreement with Energy Fuels, providing a significant advantage to the company. The mill is the only operational conventional uranium mill in the U.S. with licensed capacity of over eight million pounds (Mlb) of U3O8 per year. The mill is within trucking distance to Tony M. It is an important distinction worth noting that a toll milling agreement and the selling of ore to EFR/White Mesa are very different, with toll milling allowing IsoEnergy to participate in the upside of the uranium price.

About Tony M mine

The Tony M mine is located in eastern Garfield county, southeastern Utah, approximately 66 air miles (107 kilometres) west-northwest of the town of Blanding and 215 miles (347 kilometres) south-southeast of Salt Lake City. The project is the site of the Tony M underground uranium mine that was developed by Plateau Resources, a subsidiary of Consumer Power Company, in the mid-1970s.

Uranium and vanadium mineralization at the Tony M mine is hosted in sandstone units of the Salt Wash member of the Jurassic-age Morrison formation, one of the principal hosts for uranium deposits in the Colorado Plateau region of Utah and Colorado.

Tony M has been estimated to contain the mineral resources shown in the associated table.

Qualified person statement

The scientific and technical information contained in this news release was reviewed and approved by Dean T. Wilton: PG, CPG, MAIG, a consultant of IsoEnergy who is a qualified person (as defined in National Instrument 43-101 -- Standards of Disclosure for Mineral Projects).

About IsoEnergy Ltd.

IsoEnergy is a leading, globally diversified uranium company with substantial current and historical mineral resources in top uranium mining jurisdictions of Canada, the United States, Australia and Argentina at varying stages of development, providing near-, medium- and long-term leverage to rising uranium prices. IsoEnergy is currently advancing its Larocque East project in Canada's Athabasca basin, which is home to the Hurricane deposit, boasting the world's highest-grade indicated uranium mineral resource.

IsoEnergy also holds a portfolio of permitted, past-producing conventional uranium and vanadium mines in Utah with a toll milling arrangement in place with Energy Fuels Inc. These mines are currently on standby, ready for rapid restart as market conditions permit, positioning IsoEnergy as a near-term uranium producer.

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