Pre-Licensing Vendor Design Review

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A Pre-Licensing Vendor Design Review (VDR) is an optional service provided by the CNSC when requested by a vendor.

A VDR is a feedback mechanism that enables CNSC staff to provide feedback early in the design process based on a vendor’s reactor technology. Nuclear power plant designs can include small modular reactor (SMR) concepts, advanced reactor concepts or more traditional designs. The assessment is completed by the CNSC at the request of the vendor. The word “pre-licensing” signifies that a design review is undertaken prior to the submission of a licence application to the CNSC by an applicant seeking to build and operate a new nuclear power plant. An application by a vendor for a review is not an application for a licence to prepare a site or to construct or operate a nuclear power facility, and is not an indication of intent to proceed with a project.

This review does not certify a reactor design or involve the issuance of a licence under the Nuclear Safety and Control Act, and it is not required as part of the licensing process for a new nuclear power plant. The conclusions of any design review do not bind or otherwise influence decisions made by the Commission.

The objective of a review is to verify, at a high level, the acceptability of a nuclear power plant design with respect to Canadian nuclear regulatory requirements and expectations, as well as Canadian codes and standards. These reviews also identify fundamental barriers to licensing a new design in Canada and assures that a resolution path exists for any design issues identified in the review.

A vendor who has completed a Phase 2 Pre-Licensing VDR, has committed to increased regulatory efficiencies at the time of licensing. The results of Phase 2 will be taken into account mainly for the Construction Licence Application and is likely to result in increased efficiencies of technical reviews.

The reviews take place in three phases, each of which is conducted against related CNSC regulatory documents and Canadian codes & standards:

Phase 1: Pre-Licensing Assessment of Compliance with Regulatory Requirements: This phase involves an overall assessment of the vendor’s nuclear power plant design against the most recent CNSC design requirements for new nuclear power plants in Canada, as indicated in REGDOC-2.5.2, Design Of Reactor Facilities: Nuclear Power Plants or Design of Small Reactor Facilities (RD-367) as applicable, as well as all other related CNSC regulatory documents and Canadian codes & standards.

Phase 2: Pre-Licensing Assessment for Any Potential Fundamental Barriers to Licensing: This phase goes into further details with a focus on identifying any potential fundamental barriers to licensing the vendor’s nuclear power plant design in Canada.

Phase 3: Follow-up: This phase allows the vendor to follow-up on certain aspects of Phase 2 findings by:

  • seeking more information from the CNSC about a Phase 2 topic; and/or
  • asking the CNSC to review activities taken by the vendor towards the reactor’s design readiness, following the completion of Phase 2.

Regulatory decisions are not based on pre-licensing VDRs. Consequently, CNSC staff must balance the obligation to protect a vendor’s sensitive commercial information with the need to access this information so that they can conduct effective reviews and report on their work to the public transparently. To do so, CNSC staff prepare an executive summary of the overall conclusions and key findings of its pre-licensing VDR and post it for public information. Details of discussions and review results are released at the vendor’s discretion.

Before a VDR is undertaken, considerations are made to evaluate if there are sufficient resources to carry out the review, and if there is evidence that the conceptual design and basic engineering program is advanced enough to proceed with a useful review.

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

Pre-licensing vendor design reviews are carried out within 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 pre-licensing 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 the review 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 nuclear power plant; the conclusions of any design review do not bind or otherwise influence future decisions made by the Commission.
  • recovering costs from effort expended by CNSC staff
  • ensuring that the objectives and conduct of a review remain consistent from one vendor to the next, thereby ensuring fairness of treatment
  • striking a balance between, on the one hand, protecting a vendor’s sensitive commercial information and, on the other hand, providing CNSC staff 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

Prioritization of pre-licensing vendor design reviews

In order to optimize its resources and best fulfill its mandate and obligations to Canadians, the CNSC has prioritized activities to prepare for potential SMR licence applications . It is implementing a focused approach to accepting VDR applications, and will be giving priority to vendors that demonstrate that their design is, or may become, part of a future Canadian reactor deployment. Examples of this evidence, in order of preference are:

  1. A demonstrated partnership/relationship between the vendor and a utility or applicant: An existing utility or applicant makes a formal commitment regarding the vendor/design, the strongest of which is the presence of, or intent to submit a licenc e application to build in Canada
  2. A provincial selection process that is in progress, to which the vendor has submitted its application.
  3. 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).

These transparent well-defined criteria, which are based on tangible priorities, will enable CNSC staff to optimally manage resources – to the greater benefit of Canadians.

Status of pre-licensing vendor design reviews

Participating vendors and their review completion dates are outlined below. Please note that planned completion dates for current reviews may be adjusted as needed by mutual agreement.

Current pre-licensing vendor design reviews

The following table presents an overview of vendors who have established service agreements with the CNSC for pre-licensing engagement using the VDR process for their new reactor designs.

The duration of each review is estimated based on the vendor’s proposed schedule. A Phase 1 review typically takes 12–18 months and a Phase 2 review takes 24 months.

At the end of the review for each phase, an executive summary of the project report will be posted on this Web page.

Vendor design review service agreements in force between vendors and the CNSC
Vendor Name of design and cooling type Approximate electrical capacity (MW electrical) Applied for Review start date Status
Terrestrial Energy Inc. IMSR
Integral Molten Salt Reactor
200 Phase 1 April 2016 Complete
Phase 2 December 2018 Complete
Ultra Safe Nuclear Corporation MMR-5 and
High-temperature gas
5-10 Phase 1 December 2016 Complete
Phase 2 June 2021 Assessment in progress
ARC Nuclear Canada Inc. ARC-100
Liquid Sodium
100 Phase 1 September 2017 Complete
Phase 2 February 2022 Assessment in progress
Moltex Energy Moltex Energy Stable Salt Reactor

Molten Salt
300 Series Phase 1 and 2 December 2017 Phase 1 completed
SMR, LLC. (A Holtec International Company) SMR-160 Pressurized Light Water 160 Phase 1 July 2018 Complete
U-Battery Canada Ltd. U-Battery High-temperature gas 4 Phase 1 Pending Project start pending
GE-Hitachi Nuclear Energy BWRX-300 boiling water reactor 300 Phase 2* January 2020 Complete
X Energy, LLC Xe-100 High-temperature gas 80 Phase 2* July 2020 Assessment in Progress
Westinghouse Electric Company, LLC eVinci Micro Reactor solid core and heat pipes Up to 5 MWe Phase 2* January 2023 Assessment to Start in 2023

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

The following table presents an overview of vendors who have applied for service agreements with the CNSC to conduct a VDR for their new reactor designs. Although it typically takes a few months for the CNSC to establish and sign a service agreement, this time period can vary, depending on:

  • the organizational and technical readiness of the vendor
  • sufficient completeness of the vendor’s design activities for the Phase of VDR applied for
  • the vendor’s financial readiness to undertake the VDR
  • other legal, timing or business aspects that may influence a vendor’s decision to proceed

The CNSC does not provide details on a vendor’s decision to enter or complete the VDR process. For additional information, contact the vendor directly.

For questions about VDR, contact

Completed pre-licensing vendor design reviews

Note: Due to the commercially sensitive and proprietary information in the full report, the CNSC is only able to post the executive summaries.

For any detailed information concerning the results of a VDR, please contact the associated vendor.

GE Hitachi Nuclear Energy – BWRX-300:

Moltex Energy – SSR-W300:

SMR, LLC. – SMR-160:

ARC Nuclear Canada Inc. – ARC-100:

Ultra Safe Nuclear Corporation – MMR:

Terrestrial Energy Inc. – IMSR 400:

Candu Energy* – EC 6 (Enhanced CANDU):

* On October 2, 2011, SNC-Lavalin Group Inc. acquired certain assets of AECL’s commercial operations. The business operates as a wholly owned subsidiary called Candu Energy Inc.

Westinghouse – AP1000:



  • Phase 1 Review terminated effective December 27, 2012

AECL – ACR-1000:

Need more information?

For information, contact the CNSC.

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