ML22186A002
| ML22186A002 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 07/07/2022 |
| From: | John Lamb Plant Licensing Branch II |
| To: | Gayheart C Southern Nuclear Operating Co |
| Lamb J | |
| References | |
| EPID L-2021-LLA-0199 | |
| Download: ML22186A002 (10) | |
Text
July 7, 2022 Ms. Cheryl A. Gayheart Regulatory Affairs Director Southern Nuclear Operating Co., Inc.
3535 Colonnade Parkway Birmingham, AL 35243
SUBJECT:
EDWIN I. HATCH NUCLEAR PLANT, UNITS 1 AND 2 - AUDIT
SUMMARY
FOR LICENSE AMENDMENT REQUEST TO ADOPT RISK-INFORMED EXTENDED COMPLETION TIMES - RISK INFORMED TECHNICAL SPECIFICATIONS TASK FORCE INITIATIVE 4B (EPID L-2021-LLA-0199)
Dear Ms. Gayheart:
By letter dated October 26, 2021, (Agencywide Documents Access and Management System (ADAMS) Accession No. ML21300A153), Southern Nuclear Operating Company (SNC, the licensee) submitted a license amendment request (LAR) for Edwin I. Hatch Nuclear Plant (Hatch), Units 1 and 2. The proposed LAR would modify the plants Technical Specification requirements to permit the use of risk-informed completion times in accordance with Technical Specification Task Force Traveler TSTF-505, Provide Risk-informed Extended Completion Times, RITSTF [Risk-Informed Technical Specification Task Force] Initiative 4b.
To support its review, the U.S. Nuclear Regulatory Commission (NRC) staff conducted a virtual regulatory audit on April 5-7, May 20, and June 30, 2022. The NRC staff reviewed documents and held discussions with members of SNC and its contractors. The regulatory audit summary is enclosed with this letter.
C. Gayheart If you have any questions, please contact me by telephone at (301) 415-3100 or by e-mail at John.Lamb@nrc.gov.
Sincerely,
/RA/
John G. Lamb, Senior Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-321 and 50-366
Enclosure:
Audit Summary Attachment 1 - List of Participants Attachment 2 - List of Documents Attachment 3 - Audit Questions
OFFICE OF NUCLEAR REACTOR REGULATION REGULATORY AUDIT
SUMMARY
FOR APRIL 5-7, MAY 20, AND JUNE 30, 2022, AUDIT IN SUPPORT OF LICENSE AMENDMENT REQUEST TO ADOPT TSTF-505, RISK-INFORMED EXTENDED COMPLETION TIMES - RITSTF 4B SOUTHERN NUCLEAR OPERATING COMPANY HATCH NUCLEAR POWER PLANT, UNITS 1 AND 2 DOCKET NOS. 50-321 AND 50-366
1.0 BACKGROUND
By letter dated October 26, 2021, (Agencywide Documents Access and Management System (ADAMS) Accession No. ML21300A153), Southern Nuclear Operating Company (SNC, the licensee) submitted a license amendment request (LAR) for Edwin I. Hatch Nuclear Plant (Hatch), Units 1 and 2. The proposed LAR would modify the plants Technical Specification requirements to permit the use of risk-informed completion times in accordance with Technical Specification Task Force Traveler TSTF-505, Provide Risk-informed Extended Completion Times, RITSTF [Risk-Informed Technical Specification Task Force] Initiative 4b.
On November 29, 2021 (ML21309A000), the U. S. Nuclear Regulatory Commission (NRC) issued an audit plan, which provided the list of requested documents and other details pertaining to the audit. An audit team, consisting of NRC staff and two contractors from the Pacific Northwest National Laboratory (PNNL), conducted a remote regulatory audit to support the review of the LAR from April 5-7, May 20, and June 30, 2022. The purpose of the audit was to gain an understanding of the information needed to support the NRC staffs licensing decision regarding the LAR and to develop requests for additional information (RAIs), if necessary. The information submitted in support of the LAR is under final review, and any additional information needed to support the LAR review will be formally requested by the NRC staff using the RAI process in accordance with Office of Nuclear Reactor Regulation (NRR) Office Instruction LIC-101, Revision 6, License Amendment Review Procedures (ML19248C539).
The regulatory audit is a planned license or regulation-related activity that includes the examination and evaluation of primarily non-docketed information. The regulatory audit is conducted with the intent to gain understanding, to verify information, and/or to identify information that will require docketing to support the basis of a licensing or regulatory decision.
Performing a regulatory audit of the licensees information is expected to assist the NRC staff in efficiently conducting its review or gain insights on the licensees processes or procedures.
Information that the NRC staff relies upon to make the safety determination must be submitted on the docket. However, the NRC staff may review supporting information retained as records under Title 10 of the Code of Federal Regulations (10 CFR) Section 50.71, Maintenance of records, making of reports, and/or 10 CFR 54.37, Additional records and recordkeeping requirements, which, although not required to be submitted as part of the licensing action, would help the NRC staff better understand the licensees submitted information.
Enclosure
LIST OF DOCUMENTS REVIEWED DURING THE AUDIT 2.0 AUDIT ACTIVITIES The NRC audit team consisted of several NRC staff from NRR and two contractors from PNNL. of this enclosure provides the list of participants from NRC, Pacific Northwest National Laboratory (PNNL), the licensee, and other attendees.
The NRC audit team held an entrance meeting with the licensees staff and contractors on December 13, 2021 (ML21349A365), for the audit plan, and another entrance meeting on April 5, 2022, for the virtual audit. During the remainder of the audit, the NRC audit team participated in technical discussions with the licensee based on discipline according to the audit agenda and questions dated March 1, 2022 (ML22048C223), and email dated May 13, 2022 (ML22140A118). Attachment 2 of the enclosure includes a list of documents reviewed during the audit.
3.0 RESULTS OF THE AUDIT Technical discussions were focused on the following major areas: Probabilistic Risk Assessment (PRA) model changes since the LAR submittal, internal events, fire, seismic, and external hazards topics. The NRC audit team participated in an audit meeting with the licensee on April 5-7, 2022, where the NRC staff provided a brief summary of the teams goals, objectives, and technical discussion conclusions. There were 29 audit questions in the letter dated March 1, 2022, all audit questions were discussed.
The NRC staff provided a brief conclusion of the audit objectives that were met and details on the path forward. There were no open items in the discussion and no deviation from the audit plan.
During the audit on April 7, 2022, 24 audit questions were resolved, and the licensee agreed to provide a supplement to the application to address 2 audit questions (10 and 14). On April 29, 2022 (ML22119A144), SNC provided a supplement to the application regarding audit questions 10 and 14.
During the audit on April 7, 2022, SNC stated that it would respond to audit questions 11 and 13 when the NRC staff submitted RAI questions. On April 13, 2022, the NRC staff submitted to SNC draft RAIs regarding audit questions 11 and 13 to determine if SNC understood the questions and its regulatory basis. On April 20, 2022, SNC requested a clarifying call. During the clarifying call on May 20, 2022, SNC stated that it understood the questions and requested to respond to audit questions 11 and 13 within 90 days. On May 20, 2022 (ML22140A119), the NRC staff transmitted RAI questions 1 and 2 for audit questions 11 and 13, respectively.
During the audit on April 7, 2022, the NRC staff discovered an error in a PRA calculation pertaining to audit question 12; therefore, audit question 12 was held in abeyance pending SNC providing information on the portal. On May 9, 2022, SNC provided information related to audit question 12. On May 13, 2022 (ADAMS Accession No. ML22140A118), the NRC staff provided revised audit question 12 to SNC.
LIST OF DOCUMENTS REVIEWED DURING THE AUDIT During the clarifying call on May 20, 2022, SNC stated that it would respond to revised audit question 12 once SNC receives the RAI. On May 23, 2022, the NRC staff submitted to SNC a draft RAI regarding revised audit question 12 to determine if SNC understood the questions and the regulatory basis. On May 26, 2022, SNC requested a clarifying call to be held on June 6, 2022. During that call, SNC requested to respond to the RAI in 76 days. The NRC staff re-numbered revised audit question 12 to RAI 3 and submitted RAI 3 to SNC on June 6, 2022 (ML22157A354).
On June 30, 2022, a meeting was held to exit the audit. The audit exit meeting slides are contained in ML22181A046.
Attachments:
- 1. List of Participants
- 2. List of Documents Reviewed During Audit
- 3. Status of Audit Questions
LIST OF PARTICIPANTS U.S. Nuclear Regulatory Commission (NRC) Audit Team NAME AFFLIATION John G. Lamb NRR/DORL Dawnmathews Kalathiveettil NRR/DORL Joshua Havertape NRR/DRA/APLA Adrienne Brown NRR/DRA/APLA Keith Tetter NRR/DRA/APLC Sunwoo Park NRR/DRA/APLC Andrea Russell NRR/DSS/STSB Chris Jackson NRR/DSS/SNSB Nan Chien NRR/DSS/SCPB Joe Ashcraft NRR/DEX/EICB Norbert Carte NRR/DEX/EICB Michael Breach NRR/DEX/EMIB Nadim Khan NRR/DEX/EEEB Steve Wyman NRR/DEX/EEEB Khoi Nguyen NRR/DEX/EEEB Mark Wilk PNNL Steve Short PNNL NRR - Office of Nuclear Reactor Regulation DORL - Division of Operating Reactor Licensing DRA - Division of Risk Assessment DSS - Division of Safety Systems DEX - Division of Engineering and External Hazards APLA - Probabilistic Risk Assessment (PRA) Licensing Branch A APLC - PRA Licensing Branch C STSB - Technical Specifications Branch SNSB - Nuclear Systems Performance Branch SCPB - Plant Systems Branch EICB - Instrumentation and Controls Branch EEEB - Electrical Engineering Branch PNNL - Pacific Northwest National Laboratory Attachment 1
LIST OF PARTICIPANTS Southern Nuclear Operating Company NAME AFFILIATION Adam Quarles SNC Ryan Joyce SNC Dave Edenfield SNC Faramarz Pournia SNC Philip Ward SNC Alex Gilbreath SNC Eddie Grant SNC John Minley SNC Parthasarathy Chandran SNC Brian Coughlin SNC Dan Williamson SNC Charles Standridge Jensen Hughes
LIST OF DOCUMENTS REVIEWED DURING THE AUDIT Hatch, Units 1 and 2, Documents Available for Review on the Portal Southern Nuclear Operating Company (SNC, the licensee) provided an extensive list of supporting documents (e.g., analyses, calculations, reports, drawings, and procedures) on the Hatch document portal for review in support of the audit, as follows:
Item # Audit Item 1 Reports of full-scope and focused-scope peer reviews, facts and observations (F&Os) closure reviews, and any self-assessments referred to in license amendment request (LAR) Enclosure 2 for the internal events, internal flooding, fire, and seismic probabilistic risk assessments (PRAs) cited in the LAR 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)
- b. Identification of key assumptions and sources of uncertainty for this LAR
- 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 PRA notebooks for the Reactor Protection System 5 Documentation of how shared or cross-tied systems are modeled in the PRA 6 Hatch fire PRA notebooks containing the results of the fire PRA 7 The primary documents supporting the revised Hatch, Units 1 and 2, warning time analysis to reconfirm that the external flooding hazard can be screened out using screening criterion C5 (or using the criteria of Section 6-2-3 of ASME/ANS RA-Sa-2009 if external flooding cannot be screened as a slow-moving event).
8 The PRA notebooks associated with the modeling of Open Phase Condition (OPC) in electrical switchyards and the Open Phase Isolation System (OPIS).
9 Documentation supporting the development of the real-time risk tool and benchmarking it against the PRA 10 Documentation supporting the example risk informed completion times (RICT) calculations presented in LAR Enclosure 1, Tables E1-2 and E1-3 11 Plant and PRA configuration control procedures 12 Any draft or final RICT program procedures (e.g., for risk management actions, PRA functionality determination, and recording limiting conditions for operation) 13 Plant procedures related to risk management actions for the electrical power systems, if available 14 Relevant design documentation (e.g., single line diagrams of the electrical power distribution systems and piping and instrumentation diagrams).
15 Design details of systems shared or cross-tied between Units 1 and 2, including electrical and mechanical systems 16 Other documentation that the licensee determines to be responsive to the NRC staff's information requests Attachment 2
AUDIT QUESTIONS AUDIT QUESTION NUMBER STATUS 1 Resolved 2 Resolved 3 Resolved 4 Resolved 5 Resolved 6 Resolved 7 Resolved 8 Resolved 9 Resolved 10 SNC supplemented on April 29, 2022 (ML22119A144) 11 RAI provided to SNC on May 20, 2022 (ML22140A119) 12 RAI provided to SNC on June 6, 2022 (ML22157A354) 13 RAI provided to SNC on May 20, 2022 (ML22140A119) 14 SNC supplemented on April 29, 2022 (ML22119A144) 15 Resolved 16 Resolved 17 Resolved 18 Resolved 19 Resolved 20 Resolved 21 Resolved 22 Resolved 23 Resolved 24 Resolved 25 Resolved 26 Resolved 27 Resolved 28 Resolved 29 Resolved NOTE The audit questions were submitted to SNC by letter dated March 1, 2022 (ML22048C223).
Attachment 3
ML22186A002 OFFICE NRR/DORL/LPL2-1/PM NRR/DORL/LPL2-1/LA NRR/DSS/STSB/BC NRR/DRA/APLC/BC NAME JLamb KGoldstein VCusumano SVasavada (A)
DATE 6/30/2022 7/05/2022 7/5/2022 7/5/2022 OFFICE NRR/DRA/APLA/BC NRR/DORL/LPL2-1/BC NRR/DORL/LPL2-1/PM NAME RPascarelli MMarkley JLamb DATE 7/5/2022 7/7/2022 7/7/2022