ML23065A321
| ML23065A321 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 03/28/2023 |
| From: | Mahesh Chawla NRC/NRR/DORL/LPL4 |
| To: | Diya F Callaway Energy Center |
| References | |
| EPID L-2022-LLA-0176 | |
| Download: ML23065A321 (1) | |
Text
March 28, 2023 Mr. Fadi Diya Senior Vice President and Chief Nuclear Officer Ameren Missouri Callaway Energy Center 8315 County Road 459 Steedman, MO 65077
SUBJECT:
CALLAWAY PLANT, UNIT NO. 1 - REGULATORY AUDIT PLAN AND SETUP OF ONLINE REFERENCE PORTAL FOR LICENSE AMENDMENT REQUEST TO CLARIFY SUPPORT SYSTEM REQUIREMENTS FOR THE RESIDUAL HEAT REMOVAL AND CONTROL ROOM AIR CONDITIONING SYSTEMS (EPID L-2022-LLA-0176)
Dear Mr. Diya:
By application dated December 1, 2022 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML22335A507), Union Electric Company, doing business as Ameren Missouri (the licensee), submitted a license amendment request (LAR) for Callaway Plant, Unit No. 1.
The proposed amendment would modify the Technical Specification (TS) Bases and Final Safety Analysis Report, to allow use of one train of the normal, non-safety-related service water system to solely provide cooling water support for one of two redundant trains of TS-required equipment when both equipment trains are required to be Operable during cold shutdown/refueling conditions. The supported equipment/systems affected by the proposed change are the residual heat removal system and control room air conditioning system, as applicable during Modes 5 and 6. The applicable/affected TS limiting conditions for operation (LCOs) are TS LCO 3.4.8, RCS [Reactor Coolant System] Loops - Mode 5, Loops Not Filled; TS LCO 3.7.11, Control Room Air Conditioning System (CRACS); and TS LCO 3.9.6, Residual Heat Removal (RHR) and Coolant Circulation - Low Water Level.
The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the licensees LAR and determined that a regulatory audit would assist in the timely completion of the review. The NRC staff will conduct a regulatory audit to support its review 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.
To improve the efficiency of the NRC staff reviews, the licensees representatives and the NRC staff have discussed having an audit using an online reference portal. The NRC staff plans to initially conduct a review of the documentation provided on the portal. The audit meeting with the licensee is scheduled for April 11-12, 2023. The online reference portal would allow the
NRC staff to audit documents referenced in the request to determine whether the information included in the documents is necessary to reach a safety conclusion on the proposed amendment. The licensee will be formally requested to submit information that is needed to be submitted on the NRC docket to reach a safety conclusion. Use of the online reference portal is acceptable as long as the following conditions are met:
The online reference portal will be password-protected, and passwords will be assigned to those directly involved in the review on a need-to-know basis; The online reference portal will be sufficiently secure to prevent NRC staff from printing, saving, or downloading any documents; and Conditions of use of the online reference portal will be displayed on the login screen and will require concurrence by each user.
The NRC staff would like to request that the portal be populated with the documents listed in the attachment to the enclosure to this letter. This is the initial list identified by the NRC staff. The NRC staff may request additional documents during the review via email. Please provide the NRC staff with access to the portal and send me the information needed for access, such as username and password, as soon as possible. The conditions associated with the online reference portal must be maintained throughout the duration of the audit. Please provide written confirmation that Ameren Missouri agrees to the terms and conditions set forth in this letter.
If you have any questions, please contact me at 301-415-8371 or via email at Mahesh.Chawla@nrc.gov.
Sincerely,
/RA/
Mahesh L. Chawla, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-483
Enclosure:
Regulatory Audit Plan cc: Listserv
Enclosure REGULATORY AUDIT PLAN TO SUPPORT REVIEW OF LICENSE AMENDMENT REQUEST TO CLARIFY SUPPORT SYSTEM REQUIREMENTS FOR THE RESIDUAL HEAT REMOVAL AND CONTROL ROOM AIR CONDITIONING SYSTEMS UNION ELECTRIC COMPANY CALLAWAY PLANT, UNIT NO. 1 DOCKET NO. 50-483
1.0 BACKGROUND
By application dated December 1, 2022 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML22335A507), Union Electric Company, doing business as Ameren Missouri (the licensee), submitted a license amendment request (LAR) for Callaway Plant, Unit No. 1 (Callaway). The proposed amendment would modify the Technical Specification (TS) Bases and Final Safety Analysis Report (FSAR), to allow use of one train of the normal, non-safety-related service water (SW) system to solely provide cooling water support for one of two redundant trains of TS-required equipment when both equipment trains are required to be Operable during cold shutdown/refueling conditions. The supported equipment/systems affected by the proposed change are the residual heat removal system and control room air conditioning system, as applicable during Modes 5 and 6. The applicable/affected TS limiting conditions for operation (LCOs) are TS LCO 3.4.8, RCS
[Reactor Coolant System] Loops - Mode 5, Loops Not Filled; TS LCO 3.7.11, Control Room Air Conditioning System (CRACS); and TS LCO 3.9.6, Residual Heat Removal (RHR) and Coolant Circulation - Low Water Level.
2.0 REGULATORY AUDIT BASES, SCOPE, AND METHODOLOGY 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 to further identify material that the U.S. Nuclear Regulatory Commission (NRC) staff may determine is warranted to be submitted on the docket 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 of the LAR and to gain insights on the licensees processes and procedures. Information that the NRC staff relies upon to make the safety determination must be submitted on the docket. The basis of this remote audit is to support the NRC staff review of the licensees LAR for Callaway.
The remote audit will be performed consistent with NRC Office of Nuclear Reactor Regulation (NRR) Office Instruction LIC-111, Revision 1, Regulatory Audits, dated October 31, 2019 (ML19226A274). The NRC staff plans to initially conduct a desk audit to review the documentation provided on the portal. The audit meeting with the licensee is scheduled for April 11-12, 2023. An audit was determined to be the most efficient approach toward a timely resolution of issues associated with this LAR review, since the NRC staff will have an opportunity to minimize the potential for multiple rounds of requests for additional information (RAIs) and ensure that no unnecessary burden will be imposed by requiring the licensee to address issues that are no longer necessary to make a safety determination. Audit review items include the following:
Gain a better understanding of the detailed calculations, analyses, and bases underlying the LAR and confirm the NRC staffs understanding of the LAR.
Gain a better understanding of plant design features and their implications for the LAR.
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 RAIs per NRR Office Instruction LIC-115, Processing Requests for Additional Information, Revision 1, dated August 9, 2021 (ML21141A238).
3.0 INFORMATION AND OTHER MATERIALS NECESSARY FOR THE REMOTE REGULATORY AUDIT The NRC staff will request information as needed. The NRC staff will use an audit items list to identify the information (e.g., methodology, process information, and calculations) to be audited and the subjects of requested interviews and meetings. The NRC staff requests the licensee to have the requested audit information listed in the audit document request to be readily available and accessible for the NRC staffs review via a web-based portal.
The NRC staff requests the licensee to have the information referenced in the attachment to this audit plan available and accessible for the NRC staffs review via an online reference portal, as soon as feasible, within a few days of the issuance of this audit plan. The NRC staff requests that any supplemental information requested be available and accessible for the NRC staffs review at the licensees earliest possible date from the date of the NRCs notification to the licensee of the new requests.
4.0 AUDIT TEAM Division Branch NRR Staff Title Email DORL1 LPL42 Mahesh Chawla Project Manager Mahesh.Chawla@nrc.gov DRA3 APLC4 Marie Pohida Senior Reliability and Risk Analyst Marie.Pohida@nrc.gov Keith Tetter Reliability and Risk Analyst Keith.Tetter@nrc.gov APOB5 Andrew Mihalik Andrew.Mihalik@nrc.gov DSS6 STSB7 Matt Hamm Safety and Plant Systems Engineer Matthew.Hamm@nrc.gov SCPB8 Hanry Wagage Senior Safety and Plant Systems Engineer Hanry.Wagage@nrc.gov Gordon Curran Reactor Systems Engineer Gordon.Curran@nrc.gov SNSB9 Summer Sun Senior Nuclear Engineer Summer.Sun@nrc.gov 5.0 SPECIAL REQUESTS The NRC requests access to requested documents and information through a web-based portal that allows the NRC staff to access documents over the internet. The NRC staff access to the online portal should be terminated by July 31, 2023. The following conditions associated with the online portal must be maintained while the NRC staff has access to the online portal:
The online portal will be password-protected. A separate password will be assigned to each member of the NRC staff participating in the audit.
The online portal will prevent the NRC participants from printing, saving, downloading, or collecting any information directly from the online portal.
Conditions of use of the online portal will be displayed on the login screen and will require acknowledgment by each user.
Username and password information should be provided directly to members of the NRC staff.
The NRC licensing project manager will provide the licensee with the names and contact information of the NRC staff participating in the audit. All other communications should be coordinated through the NRC project manager.
1 Division of Operating Reactor Licensing 2 Plant Licensing Branch IV 3 Division of Risk Assessment 4 Probabilistic Risk Assessment Licensing Branch C 5 Probabilistic Risk Assessment Oversight Branch 6 Division of Safety Systems 7 Technical Specifications Branch 8 Containment and Plant Systems Branch 9 Nuclear Systems Performance Branch 6.0 DELIVERABLES The NRC staff will issue an audit summary report within 90 days of the completion of the audit.
The NRC staff will develop any RAIs, as needed, consistent with the guidance in NRR Office Instruction LIC-115, Revision 1, and issue such RAIs separately from audit-related correspondence.
7.0 AUDIT QUESTIONS Regulatory Basis Appendix A to Title 10 of the Code of Federal Regulations (10 CFR) Part 50, General Design Criteria for Nuclear Power Plants, General Design Criterion (GDC) 34, Residual heat removal, states that, A system to remove residual heat shall be provided. The system safety function shall be to transfer fission product decay heat and other residual heat from the reactor core at a rate such that specified acceptable fuel design limits and the design conditions of the reactor coolant pressure boundary are not exceeded.
Suitable redundancy in components and features, and suitable interconnections, leak detection, and isolation capabilities shall be provided to assure that for onsite electric power system operation (assuming offsite power is not available) and for offsite electric power system operation (assuming onsite power is not available) the system safety function can be accomplished, assuming a single failure.
NRC Regulatory Issue Summary 2013-05 (RIS 2013-05), NRC Position on the Relationship Between General Design Criteria and Technical Specification Operability, dated May 9, 2013 (ML13056A077), states:
It is the NRC staffs position that failure to meet general design criteria, as described in the licensing basis (e.g., nonconformance with the current licensing basis for protection against flooding, seismic events, tornadoes) should be treated as a nonconforming condition and is an entry point for an operability determination if the nonconforming condition calls into question the ability of structures, systems, and components to perform their specified safety function(s) or necessary and related support function(s).
Background:
TS 3.7.7: In Modes 5 and 6, requirements for the component cooling water (CCW) system are determined by the systems it supports.
TS 3.7.8: In Modes 5 and 6, requirements for the essential service water (ESW) system are determined by the systems it supports.
Shutdown Risk Questions
- 1.
Describe how the licensees proposed change, including the ESW and the SW systems supporting it, will meet the two shutdown initiatives described in Generic Letter (GL)
No. 88-17, Loss of Decay Heat Removal - 10 CFR 50.54(f), dated October 17, 1988 and NUMARC 91-06, Guidelines for Industry Actions to Assess Shutdown Management, dated December 1991, during Mode 5 operation with the loops not filled and Residual Heat Removal and Coolant Circulation with Low Water Level.
- 2.
Describe how the SW system is protected from hazards and events such as tornadoes, floods, missiles, pipe breaks, fires, and seismic events compared to the ESW system.
STSB Questions
- 1.
Provide detailed information related to SW system design, operation, maintenance, quality, reliability and power supply characteristics, and any additional controls to meet the requirements of 10 CFR 50.36, Technical specifications, for the use of one safety-related train and one non-safety-related train each supporting a respective RHR train when TS require two operable RHR trains.
- 2.
Proposed Callaway TS Bases submitted with the TS conversion request contained two paragraphs in the BACKGROUND section for TS 3.4.8. Between the time of the request and more recent version of the Bases, a third paragraph discussing RHR appears to have been added. Provide documents supporting the third paragraph in the BACKGROUND section for TS 3.4.8 and any NRC staff-generated documents related to the third paragraph.
SCPB Questions
- 1.
Provide the duration that the plant will be using non-safety-related SW in lieu of ESW.
- 2.
Describe operating procedures containing the requirements and procedures for the startup, operation, and monitoring associated with using the non-safety related SW configuration.
Attachment:
Requested Audit Materials List
Attachment REQUESTED AUDIT MATERIALS LIST ITEM AUDIT DOCUMENT REQUEST 1
Callaway Plant, Unit No. 1 (Callaway) evaluation that was performed showing a more than minimal increase in the likelihood of a malfunction when using service water train instead of essential service water train for residual heat removal and control room air conditioning system (last two paragraphs of LAR enclosure section 2.2).
2 Page 10 of 21 of the enclosure to LAR indicates that risk management during Modes 5 and 6 is implemented via the plants Shutdown Safety Assessment Program.
This sites program is modeled after Nuclear Management and Resources Council (NUMARC) 91-06, Guidelines for Industry Actions to Assess Shutdown Management.
Provide on the portal the document(s) that demonstrate(s) Callaways Risk Management during Modes 5 and 6.
- concurrence via email OFFICE NRR/DORL/LPL4/PM*
NRR/DORL/LPL4/LA*
NRR/DSS/SCPB/BC*
NAME MChawla PBlechman BWittick DATE 3/3/2023 3/8/2023 3/16/2023 OFFICE NRR/DSS/SNSB/BC (A)*
NRR/DSS/STSB/BC*
NRR/DRA/APLC/BC*
NAME DWoodyatt VCusumano SVasavada DATE 3/3/2023 3/17/2023 3/17/2023 OFFICE NRR/DRA/APOB/BC*
NRR/DORL/LPL4/BC*
NRR/DORL/LPL4/PM*
NAME AZoulis JDixon-Herrity MChawla DATE 3/17/2023 3/28/2023 3/28/2023