ML22110A097
| ML22110A097 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 05/09/2022 |
| From: | Marshall M Plant Licensing Branch 1 |
| To: | Rhoades D Constellation Energy Generation, Constellation Nuclear |
| Marshall, M. | |
| Shared Package | |
| ML22110A101 | List: |
| References | |
| EPID L-2022-LLT-0000 | |
| Download: ML22110A097 (30) | |
Text
OFFICIAL USE ONLY PROPRIETARY INFORMATION OFFICIAL USE ONLY PROPRIETARY INFORMATION May 9, 2022 Mr. David P. Rhoades Senior Vice President Constellation Energy Generation, LLC President and Chief Nuclear Officer Constellation Nuclear 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
LIMERICK GENERATING STATION, UNITS 1 AND 2 - REGULATORY AUDIT PLAN IN SUPPORT OF REVIEW OF DEFENSE IN DEPTH AND DIVERSITY COMMON CAUSE FAILURE COPING ANALYSIS (EPID L-2022-LLT-0000)
Dear Mr. Rhoades:
By letter dated February 14, 2022 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML22046A074), as supplemented by letter dated March 25, 2022 (ADAMS Accession No. ML22084A114), Constellation Energy Generation, LLC (Constellation, the licensee) requested that the U.S. Nuclear Regulatory Commission (NRC) review of defense in depth and diversity common cause failure coping analysis (D3 coping analysis) for the Limerick Generating Station, Units 1 and 2 (Limerick). As stated in the licensees letter dated March 25, 2022, the D3 coping analysis is part of a planned license amendment request that will be submitted to the NRC in the August 2022 timeframe to support a digital modernization project at Limerick.
During the initial review of the D3 coping analysis, the NRC staff identified several items that required further clarification and detailed explanations and determined that a regulatory audit would assist in the completion of the review. The NRC staff will conduct a regulatory audit to support its review of the D3 coping analysis in accordance with the enclosed audit plan. A regulatory audit is a planned activity that includes the examination and evaluation of primarily non-docketed information. The audit will be conducted to increase the NRC staffs understanding of the D3 coping analysis and identify information that will require docketing to support the NRC staffs regulatory finding on the planned license amendment request.
OFFICIAL USE ONLY PROPRIETARY INFORMATION D. Rhoades OFFICIAL USE ONLY PROPRIETARY INFORMATION The audit will start on May 18, 2022. The audit will consist of a series of open or partially closed public meetings using video conferencing tools and an online portal (also known as electronic portal, ePortal, electronic reading room, or eDocs web portal). The end of the audit will be scheduled after the acceptance review of the planned Limerick digital instrumentation and controls license amendment request is completed.
If you have any questions, please contact me by telephone at 301-415-2871 or by e-mail to michael.marshall@nrc.gov or Bhagwat BP Jain by telephone at 301-415-6303 or by e-mail to bhagwat.jain@nrc.gov.
Sincerely, Michael L. Marshall, Jr.
Senior Project Manager Plant Licensing Branch I Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-352 and 50-353
Enclosure:
Audit Plan cc: Listserv
/RA/
OFFICIAL USE ONLY PROPRIETARY INFORMATION Enclosure OFFICIAL USE ONLY PROPRIETARY INFORMATION AUDIT PLAN REGARDING DEFENSE IN DEPTH AND DIVERSITY COMMON CAUSE FAILURE COPING ANALYSIS CONSTELLATION ENERGY GENERATION, LLC LIMERICK GENERATING STATION, UNITS 1 AND 2 DOCKET NOS. 50-352 AND 50-353
1.0 BACKGROUND
By letter dated February 14, 2022 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML22046A074), as supplemented by letter dated March 25, 2022 (ADAMS Accession No. ML22084A114), Constellation Energy Generation, LLC (Constellation, the licensee) requested that the U.S. Nuclear Regulatory Commission (NRC) review of defense in depth and diversity common cause failure coping analysis (D3 coping analysis) for the Limerick Generating Station, Units 1 and 2 (Limerick). As stated in the licensees March 25, 2022, letter, the D3 coping analysis is part of a planned license amendment request that will be submitted to the NRC in the August 2022 timeframe to support a digital modernization project at Limerick.
2.0 REGULATORY AUDIT BASES A regulatory audit is a planned license or regulation-related activity that includes the examination and evaluation of primarily non-docketed information. The audit is conducted with the intent to gain understanding, to verify information, and to identify information that will require docketing to support the basis of a licensing or regulatory decision. Performing a regulatory audit is expected to assist the NRC staff in efficiently conducting its review and gaining insights to the licensees processes and procedures. Information that the NRC staff relies upon to make the safety determination must be submitted on the docket. This audit will be conducted in accordance with NRR Office Instruction LIC-111, Regulatory Audits, Revision 1, dated October 2019 (ADAMS Accession No. ML19226A274).
Defense-in-depth and diversity are methods that can be used to protect against common cause failures. The audit will assist the NRC staff in evaluating whether the scope and level of detail in
OFFICIAL USE ONLY PROPRIETARY INFORMATION OFFICIAL USE ONLY PROPRIETARY INFORMATION the D3 coping analysis are sufficient to demonstrate that the new instrumentation and control architecture meets the following principal design criteria described in Section 1.2.2 of the Limerick Updated Final Safety Analysis Report:
Nuclear System Process Control Criteria Power Conversion Systems Process Control and Instrumentation Criteria Electrical Power Systems Process Control Criteria Reactor Protection System Primary Containment and Reactor Vessel Isolation Control System Redundant Reactivity Control System Instrumentation and Control Systems 3.0 PURPOSE AND SCOPE The purpose of the audit is to gain a more detailed understanding of licensees D3 coping analysis for Limerick.
4.0 INFORMATION AND OTHER MATERIAL NECESSARY FOR THE REGULATORY AUDIT The NRC staff will use the Open Items Summary Table (or List) to identify the information to be audited. The Open Items Summary Table will be initially shared as an attachment to the audit plan. Consistent with the Special Request Section below, the licensee should place the Open Item List and the information to be audited on an online portal (i.e., electronic portal, ePortal, electronic reading room). The Open Items Summary Table will be updated prior to or during each of the public meetings described in the Logistic Section below.
5.0 AUDIT TEAM The members of the audit team are:
Robert Beaton, Nuclear Engineer and Audit Team Lead Charley Peabody, Nuclear Engineer Richard Stattel, Senior Electronics Engineer David Rahn, Senior Electronics Engineer Kamishan Martin, Reactor Operations Engineer Jesse Seymour, Reactor Operations Engineer Steven Alferink, Reliability and Risk Analyst Bhagwat Jain, Senior Project Manager Michael Marshall, Senior Project Manager 6.0 LOGISTICS The audit will start on May 18, 2022. The audit will consist of a series of open or partially closed public meetings using video conferencing tools and an online portal (i.e., electronic portal, ePortal, electronic reading room). The end of the audit will be scheduled after the acceptance review of the planned Limerick digital instrumentation and control license amendment request is
OFFICIAL USE ONLY PROPRIETARY INFORMATION OFFICIAL USE ONLY PROPRIETARY INFORMATION completed. The NRC project managers assigned to the audit team will coordinate any changes to the audit schedule and location with the licensee.
The first open or partially closed public meeting will be held on May 18, 2022. At the first public meeting and at subsequent meetings, the audit team and representatives from Constellation will agree on the date and time for the next meeting. The NRC staff will use the periodic public meetings to discuss the information identified in the Open Items Summary Table.
7.0 SPECIAL REQUEST The NRC staff would like access to the documents through an online portal (i.e., electronic portal, ePortal, electronic reading room) that allows the audit team access via the internet. The following conditions associated with the online portal must be maintained throughout the duration that the audit team has access to the online portal:
the online portal will be password-protected, and separate passwords will be assigned to each audit team member the online portal will be sufficiently secure to prevent the audit team from printing, saving, downloading, or collecting any information on the online portal conditions of use of the online portal will be displayed on the login screen and will require acknowledgment by each audit team member The licensee should ensure any information uploaded to the online portal is appropriately marked regarding sensitivity. NRC staff will confirm with the licensee the sensitivity of any information uploaded to the online portal.
Username and password information should be provided directly to the NRC staff on the audit team. The NRC project managers assigned to the audit team will provide Constellation the names and contact information of the NRC staff who will be participating in the audit. All communications should be coordinated with one of the NRC project managers on the audit team. The NRCs licensing project manager will inform the licensee via routine communications when the NRC staff no longer needs access to the portal. At the latest, NRC staff access to the online portal should be terminated no later than 30 days after the end of the audit.
8.0 DELIVERABLES An audit summary, which may be public, will be prepared within 90 days of the completion of the audit. If the NRC staff identifies information during the audit that is needed to support its regulatory decision, the staff will issue requests for additional information to the licensee.
OFFICIAL USE ONLY PROPRIETARY INFORMATION 24 of 30 OFFICIAL USE ONLY PROPRIETARY INFORMATION 15 SNSB Reference 17, T-121, Revision 0, LGS RPV Control - OPCON 4 EOP N
16 SNSB Reference 18, T-131, Revision 0, LGS Decay Heat Control - OPCON 5 EOP N
17 SNSB Reference 36, NEDO-2422, Assessment of BWR [Boiling Water Reactor] Mitigation of anticipated transient without scram, Volume II (NUREG 0460 Alternate No. 3, Nonproprietary version, General Electric, February 1981 N
18 SNSB Reference 38, SE-10, Revision 65, LGS Special Event Procedure N
19 SNSB Reference 39, LM-0642, Suppression Pool pH Calculation for Alternate Source Terms, Exelon N
20 SNSB Reference 42, TP18-1-008, Revision 4, BWROG Emergency Procedure and Severe Accident Guidelines Appendix B Technical Basis, Volume I: Introduction and References, June 1, 2018 N
21 SNSB NEDC-30936P-A (Referenced on page 3-26 of D3)
N 22 SNSB NEDO-24708A (Referenced on page 3-26 of D3)
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