ML24227A052
| ML24227A052 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 08/29/2024 |
| From: | Joel Wiebe Plant Licensing Branch III |
| To: | Rhoades D Constellation Energy Generation |
| Wiebe J | |
| References | |
| EPID L-2024-LLA-0055 | |
| Download: ML24227A052 (1) | |
Text
August 29, 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:
BRAIDWOOD STATION, UNITS 1 AND 2, AND BYRON STATION, UNIT NOS. 1 AND 2 - AUDIT PLAN IN SUPPORT OF REVIEW OF LICENSE AMENDMENT REQUEST REGARDING DELETION OF TECHNICAL SPECIFICATION 5.6.5.b.5 (EPID L-2024-LLA-0055)
Dear David P. Rhoades:
By letter dated April 25, 2024 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML24116A112), Constellation Energy Generation, LLC (Constellation, the licensee), submitted a license amendment request (LAR) for Braidwood Station, Units 1 and 2, and Byron Station, Unit Nos. 1 and 2, to the U.S. Nuclear Regulatory Commission (NRC).
Specifically, the proposed LAR would delete Technical Specification 5.6.5.b.5 associated with the anticipated transients without scram moderator temperature coefficient limit.
During the review of the LAR, the NRC staff identified items that require further clarification and detailed explanations. The NRC staff will conduct a regulatory audit to support its review of the LAR 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 LAR and may identify information that will require docketing to support the NRC staffs regulatory findings.
The audit will be conducted using an online portal and teleconferences. The audit plan and supporting materials are enclosed.
If you have any questions, please contact me by telephone at 301-415-6606 or via email at Joel.Wiebe@nrc.gov.
Sincerely,
/RA/
Joel S. Wiebe, Senior Project Manager Plant Licensing Branch III Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. STN 50-454, STN 50-455, STN 50-456, and STN 50-457
Enclosure:
Audit Plan cc: Listserv
Enclosure REGULATORY AUDIT PLAN REGARDING LICENSE AMENDMENT REQUEST TO DELETE TECHNICAL SPECIFICATION 5.6.5.B.5 BRAIDWOOD STATION, UNITS 1 AND 2, AND BYRON STATION, UNIT NOS. 1 AND 2 CONSTELLATION ENERGY GENERATION, LLC.
DOCKET NOS. STN 50-454, STN 50-455, STN 50-456, AND STN 50-457
1.0 BACKGROUND
By letter dated April 25, 2024 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML24116A112), Constellation Energy Generation, LLC (Constellation, the licensee), submitted a license amendment request (LAR) for Braidwood Station, Units 1 and 2, and Byron Station, Unit Nos. 1 and 2, to the U.S. Nuclear Regulatory Commission (NRC).
The proposed amendment deletes Technical Specification 5.6.5.b.5 from the core operating limits report (COLR) methodologies.
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 regulatory audit is based on the following regulatory requirements and guidance:
Title 10 of the Code of Federal Regulations (10 CFR), Part 50.62, "Requirements for reduction of risk from anticipated transients without scram (ATWS) events for light-water-cooled nuclear power plants" 10 CFR 50 Appendix A, GDC [General Design Criterion] 27, "Combined Reactivity Control System Capability" 10 CFR 50 Appendix A, GDC 28, "Reactivity Limits" 10 CFR 50 Appendix A, GDC 29, "Protection Against Anticipated Operational Occurrences" NRC Generic Letter 83-28 dated July 8, 1983 (and Supplement 1 dated October 7, 1992),
"Required Actions Based on Generic Implications of Salem ATWS Events"
3.0 SCOPE The audit team will view the documentation and calculations that provide the technical support for the LAR. The scope of the NRC staffs audit will focus on the documents listed in section 4.0 of this audit plan.
In addition, the audit team will request to discuss these topics with Constellations subject matter experts. The NRC staff will conduct this audit under the guidance provided in NRR Office Instruction LIC-111, Regulatory Audits, Revision 1 (ML19226A274).
4.0 INFORMATION AND OTHER MATERIAL NECESSARY FOR THE REGULATORY AUDIT The NRC staff requests that the documents, data, and calculations regarding the following topics be made available to the staff in Constellations electronic reading room, specifically, information related to the following and any supporting documents:
- 1. WCAP-11992, Joint Westinghouse Owners Group / Westinghouse Program: ATWS Rule Administration Process, December 1988.
- 2. Uncertainty notebooks for the Byron and Braidwood internal events, internal flooding, and fire Probability Risk Assessments (PRA) related to PRA model assumptions and sources of uncertainty.
- 3. Documentation on evaluation of the generic and plant-specific uncertainties with respect to the MTC and Unfavorable Exposure Time calculations driving the results of the Byron and Braidwood LAR.
- 4. PRA notebooks for the modeling of FLEX equipment and FLEX human error probabilities, if credited in the underlying PRA used for the Moderator Temperature Coefficient evaluation.
- 5. Plant and PRA configuration control procedures.
- 6. LAR references a pressure of 3584 psi (pounds per square inch) for steam generator (SG) tube failure (taken from WCAP-15831-P-A). The NRC safety evaluation of this document states:
However, if there are indications that the SG tubes are susceptible to failure at a lower pressure, the licensee must use the lower pressure in determining these impacts and their acceptability. The NRC requests confirmation that there is no indication that the SG tubes at the Byron/Braidwood facility are susceptible to failure at a lower pressure.
- 7. LAR references NUREG/CR-7110, Volume 2, to demonstrate that the scrubbing and decontamination provided by the SG and main steam line surfaces would mitigate the large early release. The NRC requests clarification on the specific section or text used to draw this conclusion.
- 8. Any other supporting documentation that the licensee may determine is responsive to the NRC staffs information requests.
The NRC staff acknowledges and will observe appropriate handling and protection of proprietary information made available for the audit and will not remove non-docketed information from the audit site or web portal.
5.0 AUDIT TEAM Joel Wiebe, Project Manager Joel.Wiebe@nrc.gov Jeff Circle, APLA, Technical Reviewer Jeff.Circle@nrc.gov Joshua Wilson, STSB, Technical Reviewer Joshua.Wilson@nrc.gov Malcolm Patterson, APLA, Technical Reviewer Malcolm.Patterson@nrc.gov Charley Peabody, Jr., Technical Reviewer Charley.Peabody@nrc.gov Logan Gaul, Technical Reviewer Logan.Gaul@nrc.gov 6.0 LOGISTICS The audit will be conducted remotely using video and teleconferencing and a secure, online portal, established by the licensee. The audit will begin within 2 weeks of the date of this audit plan and last until the LAR is dispositioned by the NRC. The NRC will establish audit meeting(s)
(e.g., a single, multiday audit meeting; periodic audit meetings throughout the audit period) on mutually agreeable dates and times to discuss information needs and questions arising from the NRCs review of the audited items. The NRCs licensing project manager will inform the licensee of audit meeting dates when they are established, including the date of an audit kickoff meeting.
7.0 DELIVERABLES The NRC staff will issue an audit summary report within 90 days of the audit exit.
ML24227A052 OFFICE NRR/DORL/LPL3/PM NRR/DORL/LPL3/LA NRR/DSS/SNSB/BC NAME JWiebe SRohrer PSahd DATE 8/20/2024 8/14/2024 8/23/2024 OFFICE NRR/DRA/APLA/BC NRR/DSS/STSB/BC NRR/DORL/LPL3/BC NAME JCircle for RPascarelli RElliott for SMehta JWhited DATE 8/22/2024 8/22/2024 8/27/2024 OFFICE NRR/DORL/LPL3/PM NAME JWiebe DATE 8/29/2024