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Regulatory review status for the decommissioning of the Whiteshell Reactor #1

Canadian Nuclear Laboratories (CNL) is proposing to decommission Whiteshell Reactor #1 (WR-1), using an approach that was not previously assessed when the decommissioning licence was first issued. The WR-1 is a former nuclear research reactor that operated until 1985. It is located at the Whiteshell Laboratories (WL) site in Pinawa, Manitoba, approximately 100 kilometres northeast of Winnipeg, near the towns of Lac du Bonnet and Seven Sisters.

CNL is proposing an in situ (leaving in place) decommissioning approach. In situ decommissioning involves preparing systems and structures for grouting. The below-grade grouted 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 (above-ground) structures and systems
  • installation of engineered cover over grouted area
  • final site restorations
  • 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.

This proposal requires authorization by the Canadian Nuclear Safety Commission (CNSC) in the form of an amended licence. Under the Nuclear Safety and Control Act (NSCA), CNL must apply to the Commission to amend the current decommissioning licence and undergo a review. However, before the Commission can make a licensing decision on this proposal, CNSC staff must complete an environmental assessment (EA) under the Canadian Environmental Assessment Act, 2012 (CEAA 2012).

Although the Impact Assessment Act came into force August 28, 2019, it contains provisions for ongoing projects to be completed under CEAA 2012 . This means that the CNSC will continue to lead the review of this project.

The completion of an EA under CEAA 2012 involves producing an EA report based on the information in CNL’s licensing submission, a final environmental impact statement (EIS) and other supporting documentation.

CNSC’s environmental assessment process

CNSC staff must have reviewed enough evidence and be able to show that the proposed activities would not cause significant adverse environmental effects, before the Commission can proceed with its decision. The CNSC will make this information available as Commission member documents before a public hearing, to be scheduled at a later date.

Environmental assessment start date: March 16, 2016
Reference number: 80124


Application submitted

Date Activity
April 23, 2002 CNL submits and CNSC starts review of licence application


Date Activity
May 16, 2016 Notice of commencement of the EA
June 2, 2016 Public comments invited on project description
June 3, 2016 Notice of participant funding offering
March 8, 2017 Record of decision on the scope of the EA
September 1, 2017 CNL submission of licensing documentation
October 5, 2017 Public comments invited on draft EIS
October 17, 2017 CNSC open houses (Winnipeg, Pinawa and Lac du Bonnet)
January 5, 2018 Review of CNL’s draft EIS completed
April 3, 2018 Update on the status of the EA process
April 30, 2020 CNL submission of revised draft EIS and responses to federal and provincial information requests deemed incomplete
August 24, 2022 CNL submission of revised draft EIS and responses to federal and provincial information requests deemed incomplete
January 16, 2023 CNSC technical review of EIS and licence application
April 27, 2023 Review team completes technical review of revised EIS
May 8, 2023 Review team completed technical review of EIS (including findings from Sagkeeng First Nation)
To be confirmed Review team completes technical review of revised EIS
To be confirmed CNL submission of final EIS and licence documentation
To be confirmed CNSC staff Commission member document and EA report available for public review
To be confirmed Public intervention deadline
To be confirmed Commission hearing for EA and licensing decisions
To be confirmed Commission decision announcement

Public hearing

Date Activity

To be confirmed

Commission decisions

Date Activity

To be confirmed

Licence issued

Date Activity

To be confirmed

Compliance activities

Date Activity

To be confirmed


For general CNSC updates, subscribe to the CNSC’s mailing list. For information directly related to this project, please contact:

Aimee Rupert, Environmental Assessment Officer
Telephone: 613-316-2087 or 1-800-668-5284

Mailing address: Canadian Nuclear Safety Commission
P. O. Box 1046, Station B
Ottawa, ON K1P 5S9

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