NexGen Energy Ltd. announced that on May 21st, the Company is submitting to the Federal regulator ? the Canadian Nuclear Safety Commission responses to the remaining 49 technical review comments received on February 12, 2024 as part of the Federal Environmental Assessment review process for the Company's 100% owned Rook I Project. The 49 technical comments represent the remaining aspects of the original 274 questions received from the CNSC from their technical review of the Rook I Project Draft Environmental Impact Statement ("EIS") submitted by NexGen in June 2022.

As part of this submission, NexGen has also submitted a revised Federal EIS to the CNSC as part of the response process. Leigh Curyer, NexGen's Chief Executive Officer, commented: "The Company received Provincial EA approval in November 2023 and then submitted responses to the full Federal technical review comments and received ~80% accepted in round 1. The submission of these remaining 49 responses represents another significant milestone in the final advancement of the Federal EA for the Rook I Project. The NexGen team commends the rigour and diligence of the Federal EA process which formally began 5 years ago with the submission of the Project Description ?

as it validates the technical robustness of the Project, which, once approved, will be the world's largest and lowest-cost uranium fuel producer, providing outstanding environmental, social, and economic benefits for current and future generations. All four Local Priority Area ("LPA") Communities ? the Clearwater Dene Nation ("CRDN"), Birch Narrows Dene Nation ("BNDN"), Buffalo River Dene Nation ("BRDN"), and Métis Nation ?

Saskatchewan ("MN-S") on behalf of MN-S Northern Region 2 ("NR2") ? have formally confirmed their consent and strong support for NexGen's stewardship of the Rook I Project through the signing of industry-leading Benefit Agreements. All four have fully signed off on all aspects of the Federal EA process required at this time and are advocating for its imminent approval.

In accordance with established Federal EA process, the CNSC will now conduct a completeness check of NexGen's most recent submission, which will be completed within 30 days. Upon conclusion of the completeness check, technical review of NexGen's comment responses and revised EIS will be undertaken by the CNSC through the Federal-Indigenous Review Team which is prescribed as 60 days. Upon confirmation from the CNSC that all technical comments have been resolved and acceptance of the EIS as final, the CNSC will establish a Federal Commission Hearing date.