The Canadian nuclear regulator CNSC has published three pre-project design reviews of the Candu Energy EC6, Westinghouse AP1000 and AREVA/MHI ATMEA1 reactor designs, concluding that no fundamental barriers to licensing them in Canada have been found.

However, the reports were each at different stages of the voluntary pre-licencing review process, ranging from preliminary (ATMEA1) to advanced (EC6). All three reviews included post-Fukushima lessons.

The phase 3 Candu EC6 reactor design review, the regulator said, provides a high level of assurance that Candu Energy has taken regulatory requirements and expectations into account. The reactor is a 700MW natural uranium-fuelled, heavy-water moderated, heavy water-cooled pressure-tube design. The review covered safety analysis, control system, classification of systems, structures and components, fuel design, extreme severe accidents (including Fukushima Daiichi lessons learned), and vendors’ R&D work, among others. It is a more detailed follow-up of some topics chosen by the vendor, following confirmation of the lack of fundamental barriers to licensing. The regulator said that its approvals required that Candu Energy carry out planned work as agreed. Issues raised include radiation protection design and emergency core cooling system valves.

The phase 2 Westinghouse AP1000 reactor (design control document revision 19) design review provided the vendor with additional assurance that Westinghouse has taken regulatory requirements into account. It said that there are no fundamental barriers to licensing, provided that Westinghouse resolve key findings from the stage 2 review. These include beyond design-basis accidents and severe accidents, security, and performing an upgrade of control systems and facilities to meet the new Canadian new-build code, RD-337. The regulator also noted that some issues relating to security and beyond-design basis accidents could not be reviewed due to US NRC security information restrictions.
CNSC found that the ATMEA1 design is compliant with CNSC requirements and expectations, and that the vendor understands Canadian regulatory requirements. CNSC did say that its conclusions depended on ATMEA putting in extra work in Canadian codes and standards for the 1000MWe PWR design.

The achievement of a ‘no fundamental barriers’-type approval for a PWR in Canada is significant because all operating Canadian reactors are pressurised heavy water-type designs.

In June 2012, Ontario Power Generation signed agreements with Candu Energy and Westinghouse to prepare detailed construction plans, schedules and cost estimates for two potential nuclear reactors at Darlington. Those reports were due in summer 2013.
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Picture: EC6 reactor from Candu Energy