Bruce Power – CNSC Administrative Protocol for the Review of the Innovative LBLOCA Composite Analytical Approach

Preamble

Over the past 15 years the industry has developed an integrated Large Break Loss-Of-Coolant Accident (LBLOCA) Composite Analytical Approach (CAA) which they consider to be based on sound engineering, many reactor-years of operating experience and on-going research and development.

On January 29, 2020, Bruce Power submitted a letter for the LBLOCA CAA [ref.1] and requested that CNSC re-classify breaks larger than the Threshold Break Size (TBS) from Design Basis Accidents (DBA) to Beyond Design Basis Accidents (BDBA). In response to Bruce Power’s submission, CNSC Staff accepted re-classification of LBLOCA events above the TBS as BDBAs [ref.2], and subsequently communicated to industry that the risk associated with accepting this approach in demonstrating compliance with applicable regulatory requirements is judged to be negligible [ref. 3].

Bruce Power has reached out to CNSC asking for a review outside of licensing space of information relating to its’ innovative LBLOCA CAA.

Problem Definition

Since the CNSC accepted re-classification of LBLOCA events above the TBS as BDBAs, Bruce Power and CNSC staff have been in dialogue regarding the LBLOCA CAA and have encountered several challenges that are impeding full application of the analysis methodology to the Bruce stations. To implement LBLOCA CAA within the existing regulatory framework [ref. 4], agreement is needed. Information in the following areas is needed to support the review of the proposed innovative approach:

1. Evaluation of the re-classification impact on the relevant specific safety areas (fitness-for- service, probabilistic safety analysis, deterministic safety analysis, safe operating envelope, beyond design basis analysis, emergency operating program, and severe accident management guidelines, etc. ^{Footnote 1}),
2. LBLOCA beyond design basis analysis as per REGDOC 2.4.1 and measured against the Safety Goals,
3. Evaluation of the Safe Operating Envelope (SOE), based on the remaining Design Basis Accidents (DBA) including the smaller breaks up to the TBS, to establish station operational safety margins, and
4. Risk integration from the LBLOCA CAA specific safety areas, in a holistic manner, following the risk-informed decision-making process [ref.5].

At the end of the above, Bruce Power will compile a framework which describes the components of the innovative LBLOCA CAA safety case, including information provided in support of the above items for breaks larger than the TBS and information produced outside of this review in support of breaks below the TBS. To facilitate the preparation and review of documents required for this agreement, the CNSC and Bruce Power have mutually decided to formally document the various steps in this administrative protocol.

Nothing in this protocol fetters the powers, duties or discretion of CNSC designated officers, CNSC inspectors 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 hearing process as set by the CNSC Rules of Procedure ^{Footnote 2}.

Purpose

The purpose of this protocol is to outline the administrative framework for the review of the innovative LBLOCA CAA. This protocol aims to provide efficient project management for the items described in the problem definition.

The signatories to this protocol are:

CNSC

• Executive Vice-President and Chief Regulatory Operations Officer
• Vice-President, Chief Science Officer

Bruce Power

• Chief Engineer and Senior Vice President, Engineering
• Vice President, Regulatory, Environment & Sustainability The remainder of this protocol is divided into three parts:

Part I - Framework Part II - The Project

Part III - Approvals by Signatories

Part I – Framework

1. Parties

The parties to this protocol are the CNSC and Bruce Power.

2. Duration

This protocol will come into effect on the date of the last signature to this protocol. It will terminate on the latter date when deliverables from the project are complete or when either party wishes to terminate the AP.

3. Communication / Timing

Tentative timelines for deliverables will be maintained in Part II of this document. Each party is required to notify the other as soon as practicable of any advances or delays to the schedule of 15 working days or greater. The Team co-chairs can approve changes to the schedule of up to 40 working days for each deliverable. Longer delays need to be approved by the Executive Management Committee.

4. Collaborative Review Approach

A team of experts (hereinafter referred to as the Team) will be assembled from the CNSC and Bruce Power and may also include other supporting technical experts on an as-needed basis (including observers from other power utilities). This team will be responsible for providing and reviewing relevant information to support the review of the innovative LBLOCA CAA.

A consensus building approach is being followed. Bruce Power provides the information to be reviewed and CNSC staff performs the reviews. The Team will follow a collaborative approach for dispositioning comments to allow open discussion and common understanding of the information provided, as well as to ensure consensus on agreements reached or areas of disagreement that need to be escalated. This collaborative approach will facilitate consensus building around the solution being proposed by the Team.

The deliverables are as outlined in Section 5 of Part II of this protocol.

The Team will meet at an agreed upon frequency to work through the reviews. Prior to each team meeting, required supporting information will be identified and provided, along with a clear statement of the outcome expected at each meeting. Escalation will take place if the expected outcome is not achieved after two attempts (i.e., two meetings).

5. Issue Resolution

The parties to this protocol will use their best efforts to resolve any differences of opinion in the interpretation or application of this protocol in an effective and timely manner.

The following review and dispute resolution mechanism will be used during the review to assist timely completion.

Step 1: Issue identification

It is the intention of both parties to resolve issues related to the submission of the technical information and the review through direct discussions within the Team and, where required, with the Executive Management Committee.

The Executive Management Committee is described in Part II Section 4 of this protocol.

Following the submission of technical information, the parties will hold meetings to review progress and will escalate issues to the Executive Management Committee on an as-needed basis, to highlight any potential major issues or disputes. Issues to be escalated will be documented by the Team.

Step 2: Meeting of Executive Management Committee

Where the Team cannot resolve an issue, the Executive Management Committee agrees to meet within ten working days of notification of the dispute, with the intention of expeditiously resolving the impasse. Issue resolution is to be documented by the Committee.

If an issue cannot be resolved at this level, it will be referred to the protocol signatories within ten working days of the Executive Management Committee's meeting, supported by the original or revised documentation from Step 1.

Step 3: Meeting of Signatories to this Protocol

If an issue remains unresolved after Step 2, it will be referred with documentation to the signatories to this protocol for resolution. A meeting will be called, typically within fifteen working days, to resolve the issue and document its resolution.

6. Reporting

The Team will produce reports as outlined in Part II of this protocol which will be issued on a periodic basis, demonstrating progress, status of activities, and items of concern or at risk of not being completed. The reports will be submitted by e-mail to the protocol's Executive Management Committee members as agreed to by both parties while this protocol remains in effect.

7. External Communications

Throughout this protocol's duration, all parties agree to open, transparent communications and that information destined for public release will be coordinated through assigned Single Points-Of- Contact (or alternates, where designated), with support from each party's communications division. Bruce Power is responsible for the coordination of necessary communications between the organizations with whom it has established relationships. Communications between Bruce Power and the CNSC will be done in coordination with, and in consideration of, each party's current communications guidelines.

8. Future Revisions

Significant revisions of this protocol shall be coordinated by the Executive Management Committee and approved by the signatories of this protocol. The Executive Management Committee can approve minor revisions to this protocol.

9. Details Added as Project Progresses

As additional details related to this innovation and relevant to this protocol are developed and agreed to, Bruce Power and the CNSC agree to document them in this section and make them part of this protocol.

Part II – The Project

1. Objective

The objective of this project is to review, outside the licensing process, information related to the components of the problem definition, with the goal of assessing Bruce Power’s LBLOCA CAA safety case framework and reaching conclusions regarding whether or not there are impediments to the CAA approach for LBLOCA. After the project is closed, Bruce Power plans to submit a related proposal to the CNSC for the licensing decisions.

2. Deliverables

The deliverables are as outlined in Section 5 of Part II of this protocol.

3. Team

The Team is to review the methodology and supporting documentation and address the objective outlined in Part II Section 1 in a Final Report.

1.1 Team Co-Chairs

The Team Co-Chairs will be:

• Noreddine Mesmous, Directorate of Assessment and Analysis, CNSC
• Neman Ali, Nuclear Safety Analysis, Bruce Power

The role of the Co-Chairs is to:

• Set meeting objective and agenda for all team meetings.
• Ensure meetings are scheduled.
• Moderate the Team discussions and facilitate reaching a “consensus” review conclusion.
• Initiate dispute resolution process if required as described in Part I, Section 5, Step 1.
• Prioritize the review findings, based on their technical significance, and define issue resolution in consultation with Team members.
• Make recommendations to the Executive Management Committee regarding changes to the scope, schedule, and/or budget, depending on the significance of the review findings.
• Prepare periodic progress reports and present them to the Executive Management Committee.
• Lead the production of the Team progress reports, and drafts and final reports, and present them to the Executive Management Committee.
• Perform final review of deliverables and sign off final deliverables as representatives of the Team.

1.2 Technical Panel

The mandate of the Technical Panel, working within the Team and under the guidance of the Team Co-Chairs, is to provide an independent technical review and assessment. The

Technical Panel members are selected to represent the various aspects of the Safety Case Framework, according to their area of expertise.

The members of the Technical Panel will work in good faith and will endeavor to obtain technical consensus to the extent practicable; however, they may present minority views.

1.3 Supporting Experts and Observers

The mandate of the supporting experts is to assist the Team by providing technical assistance and clarification on questions.

The role of the observers, typically representatives from other utilities, is to help foster collaborative working of the Team while maintaining their independence and ensuring objectivity of the process. Observers may also be invited to participate as supporting experts. Supporting experts and Observers shall not be part of the consensus decisions.

1.4 Technical Secretary

The Technical Secretary provides support to the Team Co-Chairs in organizing and facilitating Project meetings, recording minutes, following up on actions, and liaising with Bruce Power and external organizations to obtain relevant documentation required by the Technical Panel and Supporting Experts.

4. Executive Management Committee

The CNSC and Bruce Power will form an Executive Management Committee, comprised of senior management representatives. The members of the Executive Management Committee are as follows:

• Director General, Directorate of Assessment and Analysis, CNSC
• Director General, Directorate of Power Reactor Regulation, CNSC
• Division Director, Reactor Safety Engineering, Bruce Power
• Senior Director, Regulatory Affairs, Bruce Power

The role of the Executive Management Committee is to:

• Provide oversight to the Team.
• Approve the scope of work and the work plan.
• Decide on potential recommendations from the Team regarding changes to the scope, schedule or budget.
• Receive and review progress reports.
• Confirm that the Team final report meets the scope and objective.
• Progress the dispute resolution process, if required, as described in Part I, Section 5.
• Coordinate revisions of this protocol.

The CNSC and Bruce Power will identify an alternate if a primary Executive Management Committee member is unavailable.

5. Project Schedule

Approximate timelines for reviewing deliverables associated with the components of the problem definition are presented in this section and are based on a project start date of the date of the last signature to this protocol. Deliverables are denoted by (D), and days in the timeline refer to working days.

A detailed project plan will be prepared to describe the deliverables, activities, tasks, timelines and meetings for each component of the problem definition, and to identify the Team members and their roles and responsibilities. A project kick-off meeting with the Team will be held 15 days after the Project start date to present the project plan, confirm the scope, introduce the team members, and clarify the roles and responsibilities.
For each component of the problem definition, the following meetings will be arranged:

• Meeting 1: confirm the detailed scope of work that will be performed
• Meeting 2: provide a walk-through of the work
  • If needed, an additional meeting to address comments on the work will be held

Additional ad-hoc meetings will be arranged as needed.

In addition to the planned meetings and deliverables, the Team will prepare periodic progress reports to the Executive Management Committee.

1.5 Timeline for Evaluating the Impact of Re-classification on Relevant Safety Areas ^{Footnote 3}

Activity ID #	Activity	Approximate Timeline	Activity Owner
5.1.1	Prepare Scope/Methodology Document	Project Kick- off Meeting + 35 days	Bruce Power
5.1.2	Meet to confirm the scope of the evaluation, including CNSC Specific Safety Areas	Activity 5.1.1 + 10 days	The Team
5.1.3	Prepare report on the impact of re-classification on the impacted safety areas Footnote 4 (D): fitness-for-service (including a review of existing practices and updates to confirm leak before break) probabilistic safety assessment (including update of frequency of LBLOCA) deterministic safety analysis emergency operating program severe accident management guidelines other CNSC Specific Safety Areas	Activity 5.1.2 + 66 days	Bruce Power
5.1.4	Meet to review and agree on the outcome of the evaluations	Activity 5.1.3 + 40 days	The Team
5.1.5	If necessary, incorporate lessons learned and update report	Activity 5.1.4 + 20 days	Bruce Power
5.1.6	Perform review of final report, make updates as needed, and sign-off (D)	Activity 5.1.5 + 20 days	Team Co- Chairs
5.1.7	Presentation to the Executive Management Committee	Activity 5.1.6 + 10 days	Team Co- Chairs

1.6 Timeline for LBLOCA Beyond Design Basis Accident Analysis

Activity ID #	Activity	Approximate Timeline	Activity Owner
5.2.1	Prepare Scope/Methodology Document	Project Kick- off Meeting + 40 days	Bruce Power
5.2.2	Meet to confirm the use of best estimate analysis methodology and use of safety goals	Activity 5.2.1 + 15 days	The Team
5.2.3	Execute analysis and prepare analysis report (D)	Activity 5.2.2 + 100 days Footnote 5	Bruce Power
5.2.4	Meet to review and seek concurrence on analysis results meeting Safety Goals	Activity 5.2.3 + 40 days	The Team
5.2.5	If necessary, incorporate lessons learned and update analysis report	Activity 5.2.4 + 25 days	Bruce Power
5.2.6	Perform review of final report, make updates as needed, and sign-off (D)	Activity 5.2.5 + 30 days	Team Co- Chairs
5.2.7	Presentation to Executive Management Committee	Activity 5.2.6 + 10 days	Team Co- Chairs

1.7 Timeline for Evaluating the Safe Operating Envelope

Activity ID #	Activity	Approximate Timeline	Activity Owner
5.3.1	Prepare Scope/Methodology Document	Project Kick- off Meeting + 40 days	Bruce Power
5.3.2	Meet to confirm the scope of the evaluation	Activity 5.3.1 + 15 days	The Team
5.3.3	Review existing SOE to identify the impact of removing LBLOCA breaks greater than TBS, and define any new SOE if needed with only DBAs and document in an SOE impact report (D)	Activity 5.3.2 + 50 days	Bruce Power
5.3.4	Meet to review and seek concurrence on SOE being sufficient	Activity 5.3.3 + 40 days	The Team
5.3.5	If necessary, incorporate lessons learned and update report	Activity 5.3.4 + 20 days	Bruce Power
5.3.6	Perform review of final report, make updates as needed, and sign-off (D)	Activity 5.3.5 + 30 days	Team Co- Chairs
5.3.7	Presentation to Executive Management Committee	Activity 5.3.6 + 10 days	Team Co- Chairs

1.8 Timeline for Risk Integration from the LBLOCA CAA Specific Areas

Activity ID #	Activity	Approximate Timeline	Activity Owner
5.4.1	Prepare Scope/Methodology Document	Project Kick- off Meeting + 40 days	Bruce Power
5.4.2	Meet to confirm inputs and scope of RIDM review	Activity 5.4.1 + 15 days	The Team
5.4.3	Use RIDM process per CSA if inputs are identified. Document in a report (D)	55 days after completion of the Activities in Sections 5.1, 5.2, 5.3	Bruce Power
5.4.4	Meet to seek concurrence on RIDM findings	Activity 5.4.3 + 40 days	The Team
5.4.5	If necessary, incorporate lessons learned and update RIDM report	Activity 5.4.4 + 20 days	Bruce Power
5.4.6	Perform review of final RIDM report, make updates as needed, and sign-off (D)	Activity 5.4.5 + 20 days	Team Co- Chairs
5.4.7	Presentation to Executive Management Committee	Activity 5.4.6 + 10 days	Team Co- Chairs

1.9 Safety Case Framework (D) - Based on the deliverables in Sections 5.1 to 5.4, a framework to describe the components of the innovative LBLOCA CAA safety case for breaks above the TBS, and also covering breaks below the TBS will be compiled.

Activity ID #	Activity	Approximate Timeline	Activity Owner
5.5.1	Compile the Safety Case Framework (D)	Activity 5.4.7 + 25 days	Bruce Power
5.5.2	Review the Safety Case Framework and provide recommendations	Activity 5.5.1 + 50 days	The Team
5.5.3	Dispositions comments and update the Safety Case Framework	Activity 5.5.2 + 20 days	Bruce Power
5.5.4	Perform review of final Safety Case Framework, make updates as needed, and sign-off (D)	Activity 5.5.3 + 20 days	Team Co- Chairs
5.5.5	Presentation to Executive Management Committee	Activity 5.5.4 + 20 days	Team Co- Chairs

References

• Bruce Power Letter, M. Burton to L. Sigouin, “Bruce A and Bruce B: Large Break LOCA Safety Margins – Integrated CAA Licensing Analysis”, January 29, 2020, BP-CORR-00531-00068, e- docs#6109834
• CNSC Letter, L. Sigouin to M. Burton, “Bruce NGS A & B: Large Break LOCA Safety Margins – Integrated CAA Licensing Analysis”, August 6, 2020, e-docs#6355498
• CNSC Letter, G. Frappier and M Rinker to M. Knutson, M. Power and M. Burton, “CNSC staff’s regulatory position on the reclassification of Large Break LOCA and re-categorization of the LBLOCA-related CANDU Safety Issues”, September 30, 2020, e-docs#6359517
• CNSC REGDOC 2.4.1 “Deterministic Safety Analysis”, May 2014
• CSA N290.19:18 “Risk-informed decision making for nuclear power plants”, December 2018

Part III – Approvals by Signatories

This protocol has been approved on the dates indicated below:

Ramzi Jammal
Executive Vice-President and Chief Regulatory Operations Officer Canadian Nuclear Safety Commission

Peter Elder
Vice-President, Technical Support Branch and Chief Science Officer Canadian Nuclear Safety Commission

Gary Newman
Chief Engineer and Senior Vice President, Engineering Bruce Power

Michael Rinker
Vice President, Regulatory, Environment & Sustainability Bruce Power