Decommissioning progress for unique Canadian reactor

Canadian federal and provincial authorities have completed their technical assessment of Canadian Nuclear Laboratories' (CNL's) draft environmental impact statement (EIS) for the proposed in-situ decommissioning of Whiteshell Reactor 1 (WR-1).

The proposal would involve filling the below-grade portions of the WNR-1 reactor, shown in this diagram, with a special grout (Image: CNL)

The research reactor, which reached a maximum of 60 MWt, attained first criticality in 1962 at the Whiteshell Laboratories site in Pinawa, Manitoba. The unique reactor had vertical fuel channels, and was moderated by heavy water but cooled by an organic liquid. It was used until 1972 as a test reactor for a proposed organic-cooled Candu power reactor, and subsequently for irradiation, experimentation and heating the Whiteshell site until its closure in 1985.

At the time the reactor was shut down, deferred decommissioning was the preferred strategy for management of the main reactor building. The reactor was therefore defuelled and has been maintained in a state of "storage with surveillance", according to CNL.

CNL is now proposing to decommission WR-1 using an in-situ technique, an approach which it says will provide a safe, secure and effective disposal solution for the existing contaminated building, much of which is below ground level, while minimising risks to the health, safety and security of the public, workers and the environment. It is proposing a technique which will involve pouring a specially engineered grout into the reactor to lock contaminants in place. A protective cover at the surface which will channel water away from the site and protect it from the elements.

The federal environmental assessment of the proposed decommissioning project, which is required under Canadian environmental law, began in May 2016. The draft EIS was open to public comments from 6 October until 20 December 2017.

The Canadian Nuclear Safety Commission (CNSC), the responsible authority for the environmental assessment process, said it has identified a number of areas where additional information will need to be included in the final EIS and other technical supporting documentation. A consolidated table of over 200 information requests and comments from the CNSC and other federal and provincial authorities participating in the review - Environment and Climate Change Canada, Health Canada, Natural Resources Canada and Manitoba Sustainable Development - has now been submitted back to CNL.

CNL must address all comments received before submitting its final EIS to the CNSC, after which the regulator will then determine if the information is complete. The final EIS is expected to be submitted in April. The CNSC's assessment of the final EIS and the EA report will made available to the public for 60 days prior to a public hearing which is expected to take place in October.

Researched and writtenby World Nuclear News