ML24204A186
| ML24204A186 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 07/24/2024 |
| From: | Shilpa Arora Plant Licensing Branch III |
| To: | Rhoades D Constellation Energy Generation, Constellation Nuclear |
| Arora, S | |
| References | |
| EPID L-2024-LLA-0061, EPID L-2024-LLA-0069 | |
| Download: ML24204A186 (1) | |
Text
July 24, 2024 David P. Rhoades Senior Vice President Constellation Energy Generation, LLC President and Chief Nuclear Officer Constellation Nuclear 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
DRESDEN NUCLEAR POWER STATION, UNITS 2 AND 3 - REGULATORY AUDIT IN SUPPORT OF LICENSE AMENDMENT REQUESTS TO ADOPT TSTF-505, REVISION 2, PROVIDE RISK-INFORMED EXTENDED COMPLETION TIMES - RITSTF INITIATIVE 4B, TSTF-591, REVISION 0, REVISE RISK INFORMED COMPLETION TIME (RICT) PROGRAM, AND 10 CFR 50.69, RISK-INFORMED CATEGORIZATION AND TREATMENT OF STRUCTURES, SYSTEMS AND COMPONENTS FOR NUCLEAR POWER REACTORS (EPID L-2024-LLA-0061 AND EPID L-2024-LLA-0069)
Dear David Rhoades:
By letters dated May 8, 2024, and May 28, 2024 (Agencywide Documents Access and Management System (ADAMS) Accession Nos. ML24129A135 and ML24149A261, Constellation Energy Generation, LLC (CEG, the licensee) submitted license amendment requests (LARs) to amend the licenses for Dresden Nuclear Power Station, Units 2 and 3, Renewed Facility Operating License Nos. DPR-19 and DPR-25, respectively. The proposed LARs would adopt Technical Specifications Task Force (TSTF) Traveler-505, Revision 2, Provide Risk-informed Extended Completion Times, RITSTF [Risk-informed Technical Specifications Task Force] Initiative 4b (TSTF-505), TSTF-591, Revision 0, Revise Risk Informed Completion Time (RICT) Program, and the provisions of Title 10 of the Code of Federal Regulations (10 CFR), section 50.69, Risk-informed categorization and treatment of structures, systems and components for nuclear power reactors.
The U.S. Nuclear Regulatory Commission (NRC) staff has identified the need for a regulatory audit to examine the licensees non-docketed information with the intent to gain understanding, to verify information, or to identify information that will require docketing to support the basis of the licensing or regulatory decision.
The NRC staff will conduct the audit virtually via Teams using a licensee-established electronic portal available to NRC staff from August 12, 2024, through November 29, 2024, with formal audit meetings, as needed, to be scheduled during this period. The detailed audit plan is enclosed with this letter.
If you have any questions, please contact me by telephone at 301-415-1421 or via e-mail to Surinder.Arora@nrc.gov.
Sincerely,
/RA/
Surinder Arora, Project Manager Plant Licensing Branch LPL3 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-237 and 50-249
Enclosure:
Audit Plan Listserv
Enclosure REGULATORY AUDIT PLAN BY THE OFFICE OF NUCLEAR REACTOR REGULATION TO SUPPORT THE REVIEW OF LICENSE AMENDMENT REQUESTS TO ADOPT THE REQUIREMENTS OF TSTF-505, TSTF-591, AND 10 CFR 50.69 CONSTELLATION ENERGY, LLC DRESDEN NUCLEAR POWER STATION, UNITS 2 AND 3 DOCKET NOS. 50-237 AND 50-249
1.0 BACKGROUND
By letters dated May 8, 2024, and May 28, 2024 (Agencywide Documents Access and Management System (ADAMS) Accession Nos. ML24129A135 and ML24149A261),
Constellation Energy Generation, LLC (CEG, the licensee) submitted license amendment requests (LARs) for Dresden Nuclear Power Station, Unit Nos. 2 and 3 (DNPS). The proposed LARs would adopt Technical Specifications Task Force (TSTF) Traveler-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b (TSTF-505), TSTF-591, Revision 0, "Revise Risk Informed Completion Time (RICT) Program," and Title 10 of the Code of Federal Regulations (10 CFR), section 50.69, Risk-informed categorization and treatment of structures, systems and components for nuclear power reactors.
The staff from the U.S. Nuclear Regulatory Commissions (NRC) Office of Nuclear Reactor Regulation (NRR) has initiated its review of the LARs in accordance with NRR Office Instruction LIC-101, License Amendment Review Procedures, Revision 6, dated July 2020 (ML19248C539).
2.0 REGULATORY AUDIT BASIS A regulatory audit is a planned license, or regulation-related activity that includes the examination and evaluation of primarily non-docketed information that provides the technical basis for the LARs. An audit is conducted to gain understanding, to verify information and to identify information that will require docketing to support the basis of a licensing or regulatory decision. An audit will 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 (ML19226A274), with exceptions noted within this audit plan. The NRC staff performs the audit to support its evaluation of whether the licensees LARs can be approved per 10 CFR, section 50.90, Application for amendment of license, construction permit, or early site permit. The NRC staffs review will be informed by NUREG-0800, Standard Review Plan, section 19.2, Review of Risk Information Used to Support Permanent Plant-Specific Changes to the Licensing Basis: General Guidance, Dated June 2007 (ML071700658). The audit will assist the NRC staff with understanding the licensees proposed programs for implementing RICTs for certain technical specifications and categorizing structures systems and components (SSCs) based on their risk significance.
3.0 REGULATORY AUDIT SCOPE AND METHODOLOGY The audit team will view the documentation and calculations that provide the technical support for the LARs. The scope of the NRC staffs audit will focus on the following subjects:
Understand how the licensees proposed program conforms to NRC-endorsed guidance in Nuclear Energy Institute (NEI) report NEI 00-04, Revision 0, SSC Categorization Guideline (ML052910035), as endorsed by Regulatory Guide 1.201, Revision 1, Guidelines for Categorizing Structures, Systems, and Components in Nuclear Power Plants According to Their Safety Significance (ML061090627).
Understand how the licensees proposed program implements TSTF-505 and TSTF-591 and conforms to NRC-endorsed guidance in NEI 06-09, Revision 0-A, Risk-Informed Technical Specification Initiative 4b, Risk-Managed Technical Specification Guidelines (ML122860402).
Gain a better understanding of the detailed calculations, analyses, and bases underlying the LARs and confirm the staffs understanding of the LARs.
Gain a better understanding of plant design features and their implications for the LARs.
Identify any information needed to enable the staffs evaluation of the technical acceptability of the probabilistic risk assessment (PRA) used for these applications.
Identify any information needed to enable the NRC staffs evaluation of whether the proposed changes challenge design-basis functions or adversely affect the capability or capacity of plant equipment to perform design-basis functions.
Identify questions and requests that may become formal requests for additional information (RAIs) per NRR Office Instruction LIC-115, Processing Requests for Additional Information, Revision 1, dated August 2021 (ML21141A238).
The NRC staff will audit the PRA methods that the licensee would use to determine the risk impact from which the revised completion times for TSTF-505 would be obtained, and to categorize SSCs based on their risk significance. This will include the licensees assessments of internal events (including internal flooding), fire, and seismic PRAs, as well the treatment of uncertainties and evaluation of defense-in-depth. The NRC will also audit the licensees quantification of risk from significant external events whether the licensee uses PRA or bounding methods. In addition, the audit team will request to discuss these topics with the licensees subject matter experts.
4.0 INFORMATION AND OTHER MATERIAL NECESSARY FOR THE AUDIT The NRC staff will request information and interviews throughout the audit period. The NRC staff will use an audit items list to identify the information to be audited (e.g., methodology, process information, and calculations) and the subjects of requested interviews and meetings.
The NRC staff requests the licensee to have the information referenced in the attachment of this audit plan available and accessible for the NRC staffs review via a web-based electronic portal within two weeks of the date of this audit plan. The NRC staff requests that any supplemental information requested be available and accessible for the NRC staffs review within one week of the date of the NRCs notification to the licensee of the new requests. The NRC staff requests the licensee to notify the review team when an audit item is added to its electronic portal by sending an email to the NRC licensing project manager.
The NRC staff acknowledges and will observe appropriate handling and protection of proprietary information made available for the audit. Any information accessed through the licensees portal will not be held or retained in any way by NRC staff.
5.0 TEAM ASSIGNMENTS The audit team will consist of the following NRC staff from NRR and contractors.
Surinder Arora, Plant Licensing Branch III (LPL3); surinder.arora@nrc.gov Adrienne Brown, PRA Licensing Branch A (APLA); adrienne.driver@nrc.gov Todd Hilsmeier, APLA; todd.hilsmeier@nrc.gov Daniel Ju, PRA Licensing Branch B (APLB); daniel.ju@nrc.gov Charles Moulton, APLB; charles.moulton@nrc.gov Michael Swim, PRA Licensing Branch C (APLC); michael.swim@nrc.gov Keith Tetter, APLC; keith.tetter@nrc.gov Angelo Stubbs, Containment and Plant Systems Branch (SCPB);
angelo.stubbs@nrc.gov Gordan Curran, SCPB, gordon.curran@nrc.gov Fred Forsaty, Nuclear Systems Performance Branch (SNSB); fred.forsaty@nrc.gov Norbert Carte, Instrumentation and Controls Branch B (EICB); norbert.carte@nrc.gov Edmund Kleeh, Electrical Engineering Branch (EEEB); edmund.kleeh@nrc.gov Hari Kodali (EEEB); hari.kodali@nrc.gov Gurjendra Bedi, Mechanical Engineering and Inservice Testing Branch (EMIB);
gurjendra.bedi@nrc.gov Thomas Scarbrough, EMIB; thomas.scarbrough@nrc.gov Stephanie Garza, External Hazards Branch (EXHB); stephanie.garza@nrc.gov Hosung Ahn, EXHB; hosung.ahn@nrc.gov Jason White, EXHB; jason.white@nrc.gov Sara Tabatabai, EXHB; sarah.tabatabai@nrc.gov Rosalynn Wang, EXHB; rosalynn.wang@nrc.gov Robert Elliott, Technical Specifications Branch (STSB); robert.elliott@nrc.gov Dan Widrevitz, Vessel and Internals Branch (NVIB); dan.widrevitz@nrc.gov Stephen Cumblidge, Piping and Head Penetration Branch, stephen.cumblidge@nrc.gov Pacific Northwest National Laboratory (PNNL) contractors The NRC staff may request portal access for additional staff as the audit progresses.
6.0 LOGISTICS The audit will be conducted using a secure, online electronic portal, established by the licensee to present supporting documentation and calculations and virtually by interviews with the licensees subject matter experts. The audit will begin within 2 weeks of the date of this audit plan.
A desktop audit will take place approximately between August 12, 2024, and November 29, 2024. The NRCs licensing project manager will inform the licensee of the entrance and exit meeting dates when they are established. The NRC project manager will coordinate with the licensee to set dates and times to discuss information needs and questions arising from the NRCs review of the audited items. The NRC staff may change and/or add audit dates and times when deemed necessary. Audit meeting agenda and questions will be sent in advance of the audit meeting.
7.0 SPECIAL REQUESTS The following conditions associated with the online web-based electronic portal should be maintained while the NRC staff and contractors on the audit team have access to the online portal:
The online electronic portal will be password-protected, and separate passwords will be assigned to each member of the audit team.
The online web-based electronic portal will be sufficiently secure to prevent the NRC staff and contractors from printing, saving, downloading, or collecting any information from the web portal.
Conditions of use of the online electronic portal will be displayed on the login screen and will require acknowledgment by each user.
The licensee should provide username and password information directly to the NRC staff and contractors on the audit team, listed above. The NRC project manager will provide the licensee with the names and contact information of the NRC staff and contractors who are added to the audit team. All other communications should be coordinated with the NRC project manager. The NRCs project manager will inform the licensee via routine communications when the NRC staff no longer needs access to the electronic portal.
No data accessed by the audit team members will be retained by the NRC following the conclusion of the audit.
8.0 DELIVERABLES The NRC staff will develop any RAIs, as needed, via NRR Office Instruction LIC-115 and issue such RAIs separately from audit-related correspondence. The NRC staff will issue an audit summary report within approximately 90 days after the end of the audit and prior to completing its safety evaluations of the LARs.
Initial Audit Items List Item #
Audit Item 1
Reports of peer reviews (full-scope and focused-scope), self-assessments, and Facts &
Observations (F&Os) closure reviews for the internal events, internal flooding, fire, and seismic PRAs cited in Dresden LARs dated May 8th, and 28th 2024.
2 For the internal events, internal flooding, fire, and seismic PRAs, plant-specific documentation (e.g., uncertainty notebooks) related to:
- a. The review of the PRA model assumptions and sources of uncertainty (generic and plant-specific assumptions/uncertainties) for these LARs
- b. Identification of key assumptions and sources of uncertainty for these LARs
- c. Parametric uncertainty and state-of-knowledge correlation evaluation 3
PRA notebooks for the modeling of FLEX equipment and FLEX human error probabilities credited in the PRAs.
4 If modeled, PRA notebooks associated with the modeling of open phase condition (OPC) in electrical switchyards and the open phase isolation system (OPIS).
5 PRA notebooks associated with open F&Os for the Full Power Internal Events PRA, Internal Flooding PRA, Fire PRA, and Seismic PRA.
6 Fire PRA notebooks containing the results of the fire PRA, including risk importance measures.
7 Seismic PRA notebooks containing the results of the seismic PRA, including risk importance measures.
8 Reports cited in Attachment 4: External Hazards Screening of the 10 CFR 50.69 LAR.
9 PRA configuration control and update procedures, including when the PRA is updated (i.e.,
unscheduled and scheduled PRA updates).
10 If available, 10 CFR 50.69 SSC Categorization program procedures (e.g., categorization review and adjustment process, decision criteria for Independent Decision-Making Panel (IDP)). (The licensee may choose (optional) to provide draft procedures if final procedures are not available.)
11 If available, final RICT program procedures (e.g., for risk management actions, PRA functionality determination, and recording limiting conditions for operation). [The licensee may choose (optional) to provide draft RICT program procedures if final procedures are not available.]
12 Other documentation that the licensee determines to be responsive to the staff's information requests.
- 1. PRA Success Criteria Notebook
- 2. PRA Data Notebook
- 3. Documents cited in section 3.2.4, Other External Hazards section of the 50.69 LAR.
- 4. Documents cited in section 3 of enclosure 4 of the TSTF-505 LAR - Seismic Risk Contribution Analysis.
Section 8 of TSTF-505 LAR:
- 1. Procedure OP-DR-108-111-1004, "Cold Weather Strategy," Revision 1.
- 2. U.S. NRC letter to Commonwealth Edison Company, "'SEP Topic ll-1.C, Potential Hazards Due to Nearby Transportation, Institutional, Industrial and Military Facilities - Dresden Unit 2," Docket No. 50-237, dated August 20, 1982.
Item #
Audit Item
- 3. Calculation No. DRE22-0002, "Dresden Buried Pipe Blast and Gas Leak Analysis,"
- 4. September 7, 2023, Revision 1.
- 5. Control Room Habitability Study Update for Dresden Units 2 and 3, Enercon 2015.
- 6. Control Room Habitability Study Update for Dresden Units 2 and 3, Commonwealth Edison Company, Bechtel Power Co., December 1981.
- 7. MPR Letter 0958-0147-LTR-001, "Impact of Increasing Test and Maintenance Intervals of Turbine Overspeed Protection System Components at Dresden,"
March 2019, Revision 0.
- 8. DR-LAR-008, External Hazards Assessment for Dresden Nuclear Power Station, Revision 1.
Enclosure Section 6 of 10 CFR 50.69 LAR:
- 1. DRE 19-0026, Evaluation of Dresden's Tornado Missile Protection Design for Compliance with the Licensing Requirements, December 19, 2019.
- 2. Dresden Generating Station, Seismic PRA Peer Review Report Using ASME/ANS PRA Standard Requirements, Revision 0, March 2019.
- 3. Dresden Generating Station (Units 2&3) Report #: 32485-RPT-134-01, Seismic PRA Fact And Observation Independent Assessment, August 10, 2022.
- 4. DR-LAR-009, Assessment of Key Assumptions and Sources of Uncertainty for DNPS Nuclear Power Station, Revision 1, May 2024.
13 Relevant design documentation, e.g., single line diagrams of the electrical power distribution systems and piping and instrumentation diagrams 14 Load list for each safety-related bus 15 Plant procedures related to the risk management action for the electrical power systems, if available
ML24204A186 OFFICE NRR/DORL/LPL3/PM NRR/DORL/LPL3/LA NRR/DORL/LPL3/BC NRR/DORL/LPL3/PM NAME SArora SRohrer JWhited SArora DATE 7/22/24 7/23/24 7/23/24 7/24/24