NexGen Receives Final Federal Approval for the Rook I Uranium Project

Press Release

Vancouver, British Columbia–(- March 5, 2026) – NexGen Energy Ltd. (TSX: NXE) (NYSE: NXE) (ASX: NXG) (“NexGen” or the “Company”) is pleased to announce that the Canadian Nuclear Safety Commission (“CNSC”) has, as of today, approved NexGen’s Environmental Assessment (“EA”) and issued a Licence to Prepare Site and Construct (the “Licence”) for the Company’s 100%-owned, generational, Rook I Project (the “Project”). This approval comes 14 business days after the final 2-part Commission Hearing process which was concluded February 12, 2026. With Environmental Assessment (“EA”) approval from the Province of Saskatchewan received in November 2023 and receipt of all other necessary Provincial authorizations, the issuance of the Licence marks the final regulatory approval required to initiate full construction of the Project.

Located in Saskatchewan’s Athabasca Basin, NexGen’s Rook I Project has been methodically advanced and designed to meet NexGen’s elite environmental, safety, social and economic standards, working in lockstep with local Indigenous communities and partners. When fully operational, the Rook I Project will be the largest single source and environmentally elite uranium mine globally, incorporating state-of-the-art extraction and safety systems. In production, Rook I is capable of producing up to 30 million pounds annually – representing over 20% of the current global uranium fuel supply and over 50% of western world supply.

With approvals secured, the Company is set to begin construction of the Rook I Project, advancing long-term economic benefits, skilled jobs, sustainable growth for the region, and Canada’s nuclear energy leadership. The team, procurement, engineering, vendors, contractors and capital are in place to commence construction activities with advanced site and shaft sinking preparation. NexGen has already made its Final Investment Decision with official construction commencing in summer 2026. As per the Rook I Project schedule, construction will take 4 years from commencement.

Leigh Curyer, Founder and Chief Executive Officer of NexGen, commented: “Today’s approval represents one of the most rigorous and comprehensive regulatory processes undertaken for a resource project globally. This milestone is the result of the NexGen team’s steadfast and unrelenting focus over 12 years understanding and delivering our objectives honestly and incorporating a culture of excellence. I am incredibly proud of our team – their resilience, accountability, and dedication to advancing Rook I optimally across all aspects. This approach is what has defined our success to date and will continue through successful execution of the construction and operations phases. We moved with purpose and confidence to deliver a new standard for resources development.

On behalf of the NexGen Board of Directors, Executive team, and staff, we extend our sincere gratitude to our Indigenous Nation partners, local communities, Premier Scott Moe and the Government of Saskatchewan, Government partners, regulatory bodies, and all valued stakeholders who have contributed their expertise, trust, and dedication to the successful advancement of this generational Project over the past decade. Further, I would also like to acknowledge the Canadian Nuclear Safety Commission in demonstrating and delivering the most rigorous review for a resources project globally, ensuring Canada leads the world in the safe and environmentally sound development of mining.

The world is changing fast, and NexGen’s Rook I is now ready to be a significant contributor to global requirements for nuclear energy and Canada’s role as an energy superpower. As global demand for reliable, clean, baseload nuclear energy continues to accelerate at an unprecedented pace, uranium is the critical fuel for powering industrial electrification and the digital infrastructure of tomorrow. Simply put, energy is the key to our global growth. Nuclear is the chosen energy to supply that economic growth. NexGen is the foundational and necessary key to fueling that growth. Our team, our asset, and this moment are aligned in a way that comes along once in a generation. Together with our Nation partners and our many valued stakeholders, we are well prepared and ready to execute the construction phase of the Rook I Project with the same scope, schedule and cost precision that has defined NexGen since incorporation in 2011.”

About NexGen

NexGen Energy is a Canadian company focused on delivering clean energy fuel for the future. The Company’s flagship Rook I Project is being optimally developed into the largest low-cost producing uranium mine globally, incorporating the most elite environmental and social governance standards. The Rook I Project is supported by an N.I. 43-101 compliant Feasibility Study, which outlines the elite environmental performance and industry-leading economics. NexGen is led by a team of experienced uranium and mining industry professionals with expertise across the entire mining life cycle, including exploration, financing, project engineering and construction, operations and closure. NexGen is leveraging its proven experience to deliver a Project that leads the entire mining industry socially, technically and environmentally. The Project and prospective portfolio in northern Saskatchewan will provide generational, long-term economic, environmental, and social benefits for Saskatchewan, Canada, and the world.

NexGen is listed on the Toronto Stock Exchange, the New York Stock Exchange under the ticker symbol “NXE,” and on the Australian Securities Exchange under the ticker symbol “NXG,” providing access to global investors to participate in NexGen’s mission of solving three major global challenges in decarbonization, energy security and access to power. The Company is headquartered in Vancouver, British Columbia, with its primary operations office in Saskatoon, Saskatchewan.

Contact Information

Leigh Curyer
Chief Executive Officer
NexGen Energy Ltd.
+1 604 428 4112
lcuryer@nxe-energy.ca
www.nexgenenergy.ca

Travis McPherson
Chief Commercial Officer
NexGen Energy Ltd.
+1 604 428 4112
tmcpherson@nxe-energy.ca
www.nexgenenergy.ca

Monica Kras
Vice President, Corporate Development
NexGen Energy Ltd.
+44 7307 191933
mkras@nxe-energy.ca
www.nexgenenergy.ca

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