Decommissioning of the Gentilly-1 Waste Facility

Canadian Nuclear Laboratories (CNL) is proposing the decommissioning of the Gentilly-1 Waste Facility (G1WF), which consists of a permanently shut down, partially decommissioning prototype nuclear reactor and support structures. The G1WF is located near Bécancour, Quebec, on the south shore of the St. Lawrence River.

As per the Nuclear Safety and Control Act, CNL has applied to the Canadian Nuclear Safety Commission (CNSC) for an amendment to the existing licence, which would authorize CNL to proceed with the last phase of decommissioning activities at the G1WF. Proposed activities include the dismantling and decontamination of all remaining systems, structures, and components owned by Atomic Energy of Canada Limited (AECL), as well as the management, packaging, and safe storage of resulting radioactive and non-radioactive waste, and the remediation of the lands to satisfy industrial reuse criteria.

The G1WF is owned by AECL and operated by CNL.

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Latest update

Notice of CNSC Hearing in Writing and Section 82 Determinations

April 14, 2026 – The Canadian Nuclear Safety Commission (CNSC) will conduct a public hearing based on written submissions in July 2026. The hearing is to consider the application from Canadian Nuclear Laboratories (CNL) to amend its waste facility decommissioning licence for the Gentilly-1 Waste Facility (G1WF). The amendment being sought would authorize CNL to commence the final phase of CNL’s decommissioning plan, which includes the removal of all Atomic Energy of Canada Limited (AECL)-owned buildings and structures at the facility, as well as the remediation of lands.

In accordance with section 82 of the Impact Assessment Act (IAA), as a prerequisite to the licensing decision, the Commission must determine whether the proposed activities are likely to cause significant adverse environmental effects. The CNSC’s determination will be made by the Commission following the July 2026 public hearing, prior to the Commission making the licensing decision. Indigenous Nations and communities, members of the public, and interested parties are invited to intervene directly to the Commission regarding CNL’s licence amendment request and the federal lands assessment being conducted in accordance with the IAA. 

Requests to intervene must be filed with the Commission Registry by June 17, 2026. More information on how to intervene can be found in the Notice of Hearing in Writing and interventions can be found on the CNSC’s hearing documents web page.  

AECL is also responsible for making an environmental effects determination under section 82 of the IAA. AECL will make its determination separately from the Commission’s determination.

 

Notice of Intent – Start of Public Comment Period 

December 15, 2025 – The federal authorities intent to make a determination regarding whether the carrying out of the project is likely to cause significant adverse environmental effects. To help inform these determinations, the federal authorities are inviting public comment until February 5, 2026 respecting that determination.

Comments can be provided to communications@cnl.ca.

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Key documents

Key documents
Document number Document title File Date
1 Notice of Intent - Decommissioning of the Gentilly-1 Waste Facility PDF (71 KB) December 15, 2025

Contacts

CNL Communications and Indigenous Relations
Canadian Nuclear Laboratories
286 Plant Road
Chalk River, Ontario K0J 1J0
Email: communications@cnl.ca

Environmental Review Division
Canadian Nuclear Safety Commission
280 Slater St
Ottawa, Ontario K1P 5S9
Email: er-ee@cnsc-ccsn.gc.ca


Disclaimer

This map is for illustrative purposes. The markers represent the approximate locations based on available data. More than one marker may be identified for a given assessment.

  • Location

    • The G1WF site is located near Bécancour, Quebec. (Quebec)

  • Nature of Activity

    • Waste Management
    • Remediation and conservation

  • Assessment Status

    In progress

  • Start Date

    2025-12-15

  • Proponent

    Canadian Nuclear Laboratories

  • Authorities

    • Atomic Energy of Canada Limited
    • Canadian Nuclear Safety Commission

  • Assessment Type

    Project on federal lands

  • Reference Number

    90092

Nearby assessments

...within 200 kilometres
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