Canadian Nuclear Safety Commission ("CNSC") Hearing for the Approval of the Rook I Project

• Link to Commission Hearing that commenced at 9.00am EST November 19, 2025: here

• Commission Hearing presentation video will be available on NexGen's homepage at http://www.nexgenenergy.ca#video

Two-part public hearings represent the final step in the Federal regulatory process prior to a CNSC approval decision

Final Commission hearings follow Saskatchewan's Environmental Assessment approval in November 2023

Vancouver, British Columbia--(Newsfile Corp. - November 19, 2025) - NexGen Energy Ltd. (TSX: NXE) (NYSE: NXE) (ASX: NXG) ("NexGen" or the "Company") is pleased to be participating today in the first of two Canadian Nuclear Safety Commission ("CNSC") hearings for the final Federal approval of the Company's 100%-owned Rook I Project (the "Project"). This historic milestone marks the culmination of over twelve years of thorough, detailed, and systematic environmental studies and transparent and genuine engagement throughout the advancement of the Rook I Project.

NexGen is presenting a video during the hearing showcasing an in-depth overview of the Rook I Project. The video outlines the Project's unique characteristics and elite low environmental impact. Further, it describes the Project's compact and conventional setting, the team, controls and systems NexGen has implemented, together with the generational positive impact the Company is delivering in the local communities. The video can be found on NexGen's homepage: http://www.nexgenenergy.ca#video.

The formal Provincial and Federal regulatory approval processes commenced in 2019 with the submission of the Project Description. Over the six and a half years of regulatory engagement and review since 2019, key milestones have included the submission of the Draft Environmental Impact Statement in 2022, NexGen's licence application being deemed sufficient by the CNSC staff in September 2023, Provincial Environmental Assessment approval in November 2023, and CNSC staff acceptance of the Final Environmental Impact Statement in January 2025, including NexGen's responses to all technical and public comments received through the Federal Environmental Assessment review process. NexGen is excited to conclude the hearing process and upon a positive CNSC approval decision, will commence construction activities and advance this generational project for the local communities, Saskatchewan and Canada.