Ontario Power Generation–Canadian Nuclear Safety Commission Staff Protocol for the Application for a Licence to Operate the Darlington New Nuclear Project

May 2026

Summary of Changes

Limitations of Use

This Ontario Power Generation–Canadian Nuclear Safety Commission Staff Protocol for the Application for a Licence to Operate the Darlington New Nuclear Project (“Protocol”) is strictly administrative in nature. None of the statements in this Protocol are to be construed or interpreted as constituting a contract or as affecting the jurisdiction or discretionary powers of the Canadian Nuclear Safety Commission (CNSC) in its assessments of licence applications made in accordance with the Nuclear Safety and Control Act (NSCA) and associated regulations.

Nothing in this Protocol fetters the powers, duties, or discretion of CNSC staff or the Commission respecting regulatory decisions or taking regulatory action. Also, this Protocol does not change in any way any applicable laws or regulations, application requirements or proceeding process as set by the Canadian Nuclear Safety Commission Rules of Procedure ^{Footnote 11}.

The timelines outlined in this Protocol provide a transparent and reasonable outline of what may be expected from a regulatory perspective, but do not, and cannot, bind CNSC or Ontario Power Generation Inc. (hereinafter referred to as “OPG”) in any legally enforceable manner.

This Protocol does not, in any way, affect or influence the Commission’s potential decision on OPG’s application for a licence to operate (LTO) ^{Footnote 1}.

1.0 Introduction

On March 25, 2026, the CNSC received an application from OPG for an LTO for Unit 1, currently under construction, at the Darlington New Nuclear Project (DNNP) site, including a low- and intermediate-level waste storage structure (L&ILWSS) ^{Footnote 1}. To facilitate a well-coordinated review process, the following framework outlines how OPG and CNSC staff will collaborate throughout the application period.

1.1 Background

PG has a project for the site preparation, construction and operation of a new nuclear generating station at its existing Darlington Nuclear Generating Station site, located along the north shore of Lake Ontario, in the Municipality of Clarington. The current project scope for Darlington New Nuclear Project (DNNP) is to construct and operate a small modular reactor (SMR) of 327 megawatts electric (MWe) ^{Footnote 1}.

In December 2021, OPG announced that it had chosen the GE Vernova Hitachi Nuclear Energy BWRX-300 SMR for deployment at the DNNP site. In October 2022, OPG applied for a licence to construct (LTC) the first of up to 4 BWRX-300 power reactors and its supporting infrastructure that the DNNP facility will comprise.

On April 4, 2025, the Canadian Nuclear Safety Commission issued a power reactor construction licence (PRCL) to OPG, PRCL 32.00/2035 ^{Footnote 2}.

1.2 Purpose

The purpose of this document is to establish an administrative framework for collaboration between OPG and CNSC staff throughout the LTO application process associated with OPG’s application for a licence to operate submitted on March 25, 2026 ^{Footnote 1}. It aims to provide efficient management for the regulatory review of information submitted by OPG to CNSC staff, which will in turn support the Commission assessment and decision. The purpose of the Protocol is to establish a mutual understanding of the parties’ objectives, clear expectations for the parties, and a framework for communication, including mechanisms for escalation to resolve issues should they arise.

This document will:

• establish a communication process, both formal and informal, between OPG and CNSC staff during the staff review of the submissions associated with OPG’s LTO application.
• provide a framework to:
  • ensure that OPG provides submissions in a timely manner and that CNSC staff promptly address any issues, allowing sufficient time for a thorough review and an informed recommendation to the Commission on OPG’s LTO application.
  • identify and resolve potential licensing barriers in a timely manner to minimize the delays during the formal licensing process.

This Protocol should be followed to allow for open and transparent processes that do not fetter the discretion of the Commission.

1.3 Scope

The scope of the Protocol covers administrative activities between CNSC staff and OPG associated with the LTO application process, including the CNSC staff’s assessment of documentation submitted by OPG, as well as OPG’s responses to requests for information, questions and clarifications, for the purpose of enabling CNSC staff to develop a recommendation to the Commission. This Protocol concludes when the Commission announces its licensing decision on OPG’s LTO application ^{Footnote 1}, or if no decision is made by January 1, 2030.

1.4 Document security

The CNSC follows the Canadian Government’s Policy on Government Security, Access to Information Act and the Privacy Act for information management ^{Footnote 4 Footnote 5}. Material received as part of a matter or proceeding before the Commission is generally made available to the public. Applicants must file a Request for Confidentiality form to limit public access to the material ^{Footnote 6}. Also, it is essential that OPG classify documents appropriately when submitting them to the CNSC.

Proper classification ensures that CNSC staff can apply the correct protocols for review, storage and communication, while maintaining the integrity and confidentiality of sensitive information, when applicable. This also helps avoid delays by ensuring that CNSC staff with appropriate clearance can access the information needed for their review(s) ^{Footnote 7}.

1.5 Exchange of information

All correspondence between OPG and CNSC staff should be effectively coordinated, managed and retained by both organizations.

• Formal communication: Formal exchanges between OPG DNNP Regulatory Affairs and CNSC DNNP Licensing staff will be managed through a designated single point of contact (SPOC), as stated in section 1.5.1 of this document.
• Informal communication: Informal exchanges, whether verbal or through information sharing will be managed by way of the SPOC, as stated in section 1.5.2 of this document.

OPG DNNP Regulatory Affairs and CNSC DNNP Licensing staff regularly meet to discuss new items, review open actions and timelines, and will manage any new items and actions arising from both formal and informal communications.

The following principles should be applied for both forms of communication:

• Information shared will reflect the position of OPG or CNSC staff, not personal views.
• Subject to the informal communication SPOC agreement, OPG and CNSC subject matter experts (SMEs) may communicate directly with each other to request clarification or to share information. SME interactions must be agreed upon by OPG DNNP Regulatory Affairs and CNSC DNNP Licensing staff.
• It is recommended that members of OPG DNNP Regulatory Affairs and CNSC DNNP Licensing staff participate in, or at least be informed of, such communications. If attendance is not possible, meeting minutes or a summary of discussions should be prepared and emailed to both groups.

Formal communication

The purpose of formal communication is to document any official regulatory requests or positions from CNSC staff, and for OPG to provide an official response or a formal submission. All formal communication must have a record number associated with it in the corresponding document management systems and captured in both OPG’s and CNSC Action Tracking systems, where appropriate.

To promote transparency, communications will be evaluated for public disclosure. The originating organization (CNSC staff and OPG) will decide whether documents are fully public, partially public, or withheld for confidentiality. Both organizations will conduct monthly reviews and CNSC staff will publish document titles on the DNNP Open Government Portal ^{Footnote 8} to ensure public awareness and ease of access to information.

Informal communication

It is common for OPG and CNSC staff to engage in informal interactions. The purpose of these communications, whether by meeting, email or phone, is typically to seek clarification on specific matters. When informal comments and dispositions on deliverables are provided, they are usually compiled in a standardized template to ensure a single comprehensive record for each deliverable, with both parties tracking resolution.

Although informal communication is valuable to seek clarity and may lead to agreed-upon actions, it will not be used to convey staff’s position on regulatory matters or to confirm that commitments are made or fulfilled; for these matters, the formal communication process will be used.

2.0 Roles and Responsibilities

For the purposes of the Protocol, OPG shall be represented by:

• Senior manager, Regulatory Affairs – Nuclear Regulatory Affairs Strategy, OPG
• Single point of contact, Regulatory Affairs* – Nuclear Regulatory Affairs Strategy, OPG

For the purposes of this Protocol, CNSC staff shall be represented by:

• Director of the Darlington Regulatory Program Division
• Single points of contact, Darlington Regulatory Program Division*

* Specific single points of contact will be established and controlled by both organizations outside of the Protocol.

3.0 Application Work

CNSC staff will review the application for an LTO, in accordance with REGDOC-1.1.3, Licence Application Guide: Licence to operate a Nuclear Power Plant. OPG is also expected to align with the requirements and expectations for an LTO application previously communicated by CNSC staff ^{Footnote 9}.

All submissions made in support of the LTO application must clearly state that purpose:

• in a subject line and/or
• in the introductory section of the letter.

If a submission pertains to both licence to construct (LTC) and LTO activities, the letter must:

• clearly state that it applies to both the LTC licence and the LTO application
  • within the same letter, it should differentiate how the submission applies to the LTC, (e.g. an open CNSC staff action request, information request) from the LTO related requirements
• ensure the submission is sent to both the Darlington Regulatory Program Division DNNP and the Advanced Reactor Licensing Division at the CNSC
• the letter must identify a summary of the key differences between the revisions and a discussion on the significance of the change for submissions that are revised from LTC to LTO.

OPG is expected to ensure all submissions that overlap with the amendment for construction of L&ILWSS include:

• a statement of what the submission letter is intended to support, either the LTC amendment for construction of the L&ILWSS or to support the LTO application
• an indication of the relevant regulatory requirements
• identification of the appropriate CNSC staff are listed in the letter

3.1 OPG submission schedule to CNSC

Table 1 outlines OPG’s committed dates for submitting the LTO document package to the CNSC while Table 2 details the committed dates for the submission of the SMR management system document sets to the CNSC ^{Footnote 3 Footnote 10} (collectively, the “OPG submission schedule”).

With respect to the L&ILWSS, OPG is seeking Commission approval to operate the facility, and the application for an amendment to the licence to construct (LTC), detailing the construction of the L&ILWSS, will be submitted by Q2 2027. OPG is also proposing an LTO regulatory hold point for commitments identified in table 32 of appendix D of the application.

OPG submission schedule:

All the deliverables detailed in the above tables are to be referred to as “OPG deliverables”.

OPG will use reasonable effort to support a timely and efficient review process by providing complete and substantive information to CNSC staff for the OPG deliverables in accordance with the OPG submission schedule.

CNSC staff require sufficient time to conduct a comprehensive review of the information contained in package #3.

OPG anticipates providing information progressively, as it becomes available, well in advance of this deadline, to ensure CNSC staff have adequate time to review the OPG deliverables.

3.2 Anticipated review timelines of OPG deliverables

CNSC staff’s review process of the OPG applications began when OPG submitted its application for an LTO to the Registry on March 25, 2026. CNSC staff will assess whether the information provided meets regulatory requirements and will identify any areas where additional information or clarification is needed.

Specific dates for potential proceedings and record of decision are set by the Commission Registry, not by CNSC staff nor OPG. As the LTO application will be submitted in stages rather than as a single package, the typical 24-month timeline for CNSC staff to complete its review and prepare a recommendation to the Commission through the Commission member document process will not apply, and currently is estimated to be approximately 35 months.

CNSC staff may require up to 5 months to review each submission package, depending on its complexity and the quality and completeness of the submitted material in conformance with regulatory requirements and guidance, as outlined in table 1.

Disclaimer: In some instances, the number of days may be extended as these timelines do not include processing times of the application and responses.

Upon receipt of the OPG application(s) CNSC staff will endeavor to complete their review in accordance with the timelines set out in Table 3 ,without compromising or limiting the effort required for a thorough and diligent technical review in accordance with regulatory requirements.

The planned review times may be extended under various circumstances including, but not limited to:

• any significant changes made to the design or safety analysis of the nuclear power plant made by OPG that may have the potential to adversely affect the safety of the facility
• any delay in OPG’s submission schedule
• the sufficiency of the information provided by OPG; for an expeditious review, the submissions must be complete, comprehensive, and of sufficient quality to ensure that the review can be carried out in an efficient manner
• the timeliness required for resolving information requests issued by CNSC staff
• delay in OPG’s response to information requests issued by CNSC staff
• any outstanding issues from activities for the licence to construct that impact the assessment of the LTO application
• additional time required for CNSC review if OPG deliverables are not in conformance with this Protocol or regulatory requirements
• any additional time to ensure adequate public and Indigenous engagement and to assess and conduct consultation activities with Indigenous Nations or communities
• unanticipated CNSC resource shortages

In circumstances where review timelines may be delayed:

• OPG and CNSC staff will communicate, via letter, delays to review timelines to the other Party as soon as they are reasonably able to
• CNSC staff will continue reviewing material in other OPG Deliverables where possible
• OPG and CNSC staff will provide updated estimated timelines, via letter, for the completion of applicable work and resolutions

3.3 Revisions to OPG submission schedule

The Parties may need to revise the timelines set out in the OPG submission schedule or the CNSC staff anticipated review timelines; this may be done by mutual written agreement, at the director level, including via email, and such revisions will replace the timelines set out in the OPG submission schedule or CNSC staff anticipated review timelines of OPG deliverables, as applicable, and amend the Protocol accordingly.

3.4 Results of the technical review

During the technical review, of each package of OPG deliverables, CNSC staff will issue an information request (IR) if it is determined that there is further clarification required. IRs will be tracked by both organizations, discussed at recurring meetings and closed when resolution is attained. OPG will submit the requested information within 60 business days of receipt for CNSC staff to complete reviews ^{Footnote 12}. CNSC staff will confirm whether the additional information provided is sufficient and if and when possible, provide closure of any information requests. Delays in OPG responses to IRs will adversely affect CNSC staff’s ability to complete reviews and provide recommendations to the Commission.

3.5 Issue resolution

If differences of opinion or interpretation and application of regulatory documents should arise, it is OPG and CNSC’s intention to utilize an issues resolution process outlined below. Notwithstanding the issues resolution process outlined below, CNSC staff retain their unfettered authority to exercise their powers, duties or discretion as set out in the NSCA or the regulations thereunder.

The frequency of these issues resolution meetings can be adjusted as need arises and agreed by both OPG and CNSC staff.

Table 4 summarizes the issue resolution process.

3.6 Managing change

Proposed changes to an LTO submission as part of an OPG Deliverable must be submitted, in writing, to the CNSC staff. How the change is submitted depends on the type of change ^{Footnote 13}:

• Changes with no licensing basis impact and no safety significance may be reported as a quarterly update.
  Example: minor editorial changes
• Changes with potential licensing basis impact but no safety significance may be reported as a quarterly update with additional details (such as reasons for making the change).
• Changes with potential licensing basis impact and safety significance will require OPG to notify CNSC immediately, and will need to include the following information:
  1. overview and rationale for the change
  2. description of licensing basis impact
  3. description of safety analysis impact (neutral or negative impact for margin) and clearly identify the resubmitted sections

Note that changes that are safety significant may affect CNSC staff review timelines.

3.7 Project communications

Monthly or more frequent meetings based on agreement between OPG and CNSC staff at the manager and director level will be held to discuss the review progress and highlight any potential major issues. At a working level, CNSC staff may meet with OPG as described in Step 1Table, Issue resolution. On a quarterly basis, or more frequently, executive-level meetings will be held between OPG and CNSC staff to discuss the overall progress for the project and any issues as required.

3.8 Licence to operate commitments

All outstanding licensing commitments made under previous licences, including those from PRCL 32.00/2035, must be tracked and reported to CNSC staff throughout the LTO application process. OPG will submit these regulatory commitments as part of the OPG DNNP commitments report.

3.8.1 Regulatory hold points

To support effective licence implementation, the Commission may establish regulatory hold points to enable CNSC staff to verify that Commission‑approved actions or commitments have been completed before a licensee proceeds to subsequent activities.

For any regulatory hold points proposed, the applicant would be expected to clearly describe the associated commitments and proposed criteria. CNSC staff would review this information and consider if it is appropriate and in conformance with regulatory requirements to include it as a recommendation to the Commission. Assessment and determination of the potential issuance of regulatory hold points rests solely with the Commission.

4.0 Revisions of the Protocol

Significant material revisions of this Protocol shall be coordinated by the managers and approved by the signatories of this Protocol. Directors can approve minor revisions (e.g., timelines, editorial corrections, clarification of text or updates to organizational structure) to this Protocol.