In Situ Decommissioning of the Whiteshell Reactor #1

Pinawa (Manitoba)

Reference number: 80124
Federal Responsible Authority: Canadian Nuclear Safety Commission
Proponent: Canadian Nuclear Laboratories
Environmental Assessment Commenced: 2016-05-16
Environmental Assessment Type: Environmental Assessment by Responsible Authority
Status: Environmental assessment in progress

Latest Update

October 16, 2018 - The timelines in Appendix A of the CNL-CNSC Administrative Protocol for the Renewal of the Whiteshell Laboratories Licence and the Proposed In Situ Decommissioning of the WR-1 Reactor have been updated to clarify the environmental assessment (EA), licensing and public hearing processes for the review of the Whiteshell project. Canadian Nuclear Laboratories (CNL) has indicated that they require additional time to address information requests (IRs) received on the draft Environmental Impact Statement (EIS) from the federal and provincial authorities as well as from Indigenous groups and members of the public. Given that there are no firm time commitments for receipt of CNL's completed responses, or for the remainder of the regulatory process, Appendix A has been revised to clarify the milestones remaining in the EA and licensing processes and the current focus of obtaining a complete submission of information. The required timelines for the federal and provincial authorities to complete their reviews remain the same. More information is available here.

About the Proposal

Canadian Nuclear Laboratories (CNL) is proposing to decommission the Whiteshell Reactor #1 (WR-1 Reactor), a former nuclear research reactor that operated until 1985. The WR-1 Reactor is located at the Whiteshell Laboratories (WL) site in Pinawa, Manitoba, which is situated approximately 100 kilometres northeast of the city of Winnipeg and located near the towns of Lac du Bonnet and Seven Sisters.

CNL is proposing an in situ (leaving in place) decommissioning approach. In situ decommissioning of the WR-1 Reactor involves preparing systems and structures for grouting whereby the below-grade sealed structure will encapsulate and contain radiological sources and hazardous materials for a defined period of institutional control.

The following activities are being proposed:

  • preparation for in situ decommissioning
  • grouting of below-grade (underground) structures and systems
  • removal of above-grade structures and systems
  • installation of engineered cover over grouted area
  • final site restoration
  • long-term care and maintenance activities

Some temporary infrastructure – such as construction trailers and equipment paddocks, as well as an increase to the electrical services – would also be required in order to facilitate decommissioning. Additional groundwater monitoring wells would be installed, as required, to monitor the performance of the in situ decommissioned facility.

Under the Nuclear Safety and Control Act, CNL's proposal requires an amendment to its existing Decommissioning Waste Facility Licence issued by the Canadian Nuclear Safety Commission (CNSC). An environmental assessment conducted under the Canadian Environmental Assessment Act, 2012 is required, and an EA decision affirming that the proposed activities will not cause significant adverse environmental effects, before the CNSC can make a licensing decision on this proposal.


  • For Public Participation (7)
    Contains all documents related to public participation opportunities
  • News Releases (9)
    Contains all news releases related to this environmental assessment process.
  • Comments Received/Responses (41)
    Contains comments received related to the environmental assessment process and, when applicable, responses to those comments.
  • Additional Information (7)
    Contains additional records related to the project and the environmental assessment process.
List and Search All Documents

External Links

Please note that access to external websites is provided solely as a courtesy. Users should be aware that the information offered by non‑Government of Canada websites that are not subject to the Official Languages Act might be available in only one language.

For questions or information, please contact:

Canadian Nuclear Safety Commission
Heather Harpell, Environmental Assessment Specialist
280 Slater Street
P.O. Box 1046, Station B
Ottawa, Ontario K1P 5S9
Telephone: 613-947-0554 or 1-800-668-5284
Fax: 613-995-5086

Date modified: