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Vendor design review

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A vendor design review (VDR) is an optional service provided by the CNSC at the request of a vendor (seller of the design, often the designer). It is a mechanism that enables CNSC staff to provide feedback to a vendor early on in the design process of its nuclear power plant (NPP). These designs can include small modular reactor (SMR) concepts, advanced reactor concepts or more traditional designs.

The objective of a VDR is to verify, at a high level, that Canadian nuclear regulatory requirements and expectations, as well as Canadian codes and standards, will be met. A VDR also serves to identify, and potentially resolve, any fundamental barriers to licensing for a new design in Canada.

An application for a VDR is not an application for any type of licence under the Nuclear Safety and Control Act. A VDR does not involve the issuance of a licence and does not certify a reactor design. It is not required as part of the licensing process for a new NPP, and its conclusions do not bind or otherwise influence decisions made by the Commission.

A VDR takes place in 3 phases, each of which is conducted against applicable CNSC regulatory documents and Canadian codes and standards.

Phase 1: Assessment of compliance with regulatory requirements

This phase involves an overall assessment of the vendor’s design and design process against the most recent CNSC design requirements for new NPPs in Canada, as set out in REGDOC-2.5.2, Design of Reactor Facilities, and against all other related CNSC regulatory documents and Canadian codes and standards.

Phase 2: Assessment for potential fundamental barriers to licensing

This phase goes into further detail, with a focus on identifying potential fundamental barriers to licensing the NPP design in Canada. It serves to give the CNSC a significant level of assurance that the vendor has considered CNSC design requirements. The results of a Phase 2 review help the vendor develop a preliminary safety analysis report to support an eventual application for a licence to construct.

Phase 3: Follow-up

This phase allows the vendor to follow up on certain aspects of unresolved issues from Phase 2. A vendor can:

  • seek more information from the CNSC about any Phase 2 issues
  • ask the CNSC to review the activities it has undertaken after the completion of Phase 2 to ensure the reactor’s design readiness

For more information on the CNSC’s VDR process, please refer to REGDOC-3.5.4, Pre-Licensing Review of a Vendor’s Reactor Design.

Service agreements

VDRs are carried out as part of a service agreement. A service agreement is a legal document that establishes the terms and conditions between the CNSC and a reactor vendor. These terms and conditions enable the CNSC to conduct a VDR in accordance with the Nuclear Safety and Control Act and its regulations. The agreement serves as a mechanism for:

  • preserving the CNSC’s regulatory independence by reinforcing the fact that the VDR being undertaken:
    • does not certify a reactor design
    • does not involve the issuance of a licence under the Nuclear Safety and Control Act
    • is not required as part of the licensing process for a new NPP; the conclusions of any design review do not bind or otherwise influence future decisions made by the Commission
  • recovering costs for the work done by CNSC staff on the review
  • ensuring that the objectives and conduct of a VDR remain consistent from one vendor to the next, thereby ensuring fairness of treatment
  • striking a balance between protecting a vendor’s sensitive commercial information, providing CNSC staff with access to this information for the purposes of performing an effective review, and transparently communicating the CNSC’s activities to the public, to the extent practicable

As per the terms of the service agreement, the detailed information resulting from a VDR is considered commercially confidential. Consequently, to report on their work to the public transparently, CNSC staff publish an executive summary of the VDR’s overall conclusions and key findings (see the links under “Completed reviews” below).

Prioritization of VDRs

Before a VDR is undertaken, it must be determined whether there are sufficient CNSC resources to carry out the review and whether there is evidence that the conceptual design and basic engineering program are advanced enough to ensure that the review will be useful.

In order to optimize its resources and best fulfill its mandate and obligations to Canadians, the CNSC’s approach to accepting VDR applications is to give priority to vendors who can provide evidence that their designs are, or may become, part of a future Canadian reactor deployment. Some examples of this evidence can be:

  • a demonstrated partnership between the vendor and an existing utility (potential applicant), with a formal commitment to the vendor to build its design in Canada
  • a signal from the Government of Canada, made in consultation with provincial stakeholders, that a review of a reactor design is in the national interest (includes technology development funding)
  • proof that the vendor has applied to a provincial selection process that is in progress

Current reviews

The following table lists the vendors who have a service agreement in force with the CNSC for a VDR of their reactor design. At the end of each VDR phase, an executive summary of the project report is posted on this web page (see the links under “Completed reviews” below).

For questions about the VDR process, contact

Vendor design review service agreements in force between vendors and the CNSC
Vendor Name of design (cooling type) Approximate electrical capacity Applied for Review start date Review status
USNC-Power Ltd. MMR
(high-temperature gas)
5 MWe Phase 2 June 2021 On hold
ARC Clean Technology ARC-100
(liquid sodium)
100 MWe Phase 2 February 2022 Assessment in progress
Westinghouse Electric Company eVinci
(heat pipes / solid core)
5 MWe Phase 2* June 2023 Assessment in progress

Note: *Phase 1 objectives will be addressed within the Phase 2 scope of work.

MWe = megawatts electric

Completed reviews

Below is a list of completed reviews. Given the commercially sensitive and proprietary information in the full reports, the CNSC is only able to post the executive summaries. For any detailed information about the results of a VDR, please contact the associated vendor.

X-energy – Xe-100 high-temperature gas

GE Hitachi Nuclear Energy – BWRX-300

Moltex Energy – SSR-W300

SMR, LLC (Holtec International) – SMR-160

ARC Clean Technology – ARC-100

USNC-Power Ltd. – MMR

Terrestrial Energy Inc. – IMSR400

Candu Energy Inc. – EC6

Westinghouse Electric Company – AP1000


AECL – ACR-1000

Preliminary regulatory design assessment

A preliminary regulatory design assessment is a mechanism that enables CNSC staff to provide feedback early on in the design process for individual elements of a vendor’s technology, using aspects of the vendor design review (VDR) process but without assessing the full reactor design.

Learn more about preliminary regulatory design assessments.

Need more information?

For information, contact the CNSC.

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