CP-202300416, Supplemental Information to Facilitate Acceptance of Licensee Amendment Request 23-002, Application Regarding GDC-5 Shared System Requirements
| ML23285A096 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 10/12/2023 |
| From: | John Lloyd Luminant, Vistra Operating Co. (VistraOpCo) |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| CP-202300416, TXX-23067 | |
| Download: ML23285A096 (1) | |
Text
CP-202300416 TXX-23067 October 12, 2023 U. S. Nuclear Regulatory Commission Ref 10 CFR 50.90 ATTN: Document Control Desk Washington, DC 20555-0001
Subject:
Comanche Peak Nuclear Power Plant Docket Nos. 50-445 and 50-446 Supplemental Information to Facilitate Acceptance of Licensee Amendment Request 23-002, Application Regarding GDC-5 Shared System Requirements
Dear Sir or Madam:
Pursuant to 10 CFR 50.90, Vistra Operations Company LLC (Vistra OpCo) requested approval of a license amendment (LAR), per Reference 1. The NRC requested, and Vistra OpCo submitted, supplemental information to assist the NRC in accepting the LAR in References 2 and 3 respectively. Vistra OpCo is now submitting the enclosed supplemental information to facilitate the NRC review of the LAR in the attached enclosure.
There are no new regulatory commitments made in this submittal.
Should you have any questions, please contact Ryan Sexton at (254) 897-6267 or ryan.sexton@vistracorp.com.
I state under penalty of perjury that the foregoing is true and correct.
Executed on October 12, 2023.
Sincerely, Jay Lloyd
Enclosure:
Supplemental Request and CPNPP Response Jay Lloyd Senior Director, Engineering and Regulatory Affairs Comanche Peak Nuclear Power Plant (Vistra Operations Company LLC)
P.O. Box 1002 6322 North FM 56 Glen Rose, TX 76043 T
254.897.5337 Jay Lloyd (Oct 12, 2023 07:59 CDT)
TXX-23067 Page 2 of 2 c (email):
John D. Monninger, Region IV [John.Monninger@nrc.gov]
Dennis Galvin, NRR [Dennis.Galvin@nrc.gov]
John Ellegood, Senior Resident Inspector, CPNPP [John.Ellegood@nrc.gov]
Dominic Antonangeli, Resident Inspector, CPNPP [Dominic.Antonangeli@nrc.gov]
References:
- 1. Luminant letter from Jay Lloyd to U.S. NRC dated April 20, 2023, "License Amendment Request (LAR)23-002, Application Regarding GDC-5 Shared Systems Requirements" (ADAMS Accession Number ML23110A156)
- 2. NRC letter from Dennis J. Galvin to Ken J. Peters dated May 31, 2023, "Comanche Peak Nuclear Power Plant, Unit Nos. 1 and 2 - Supplemental Information Needed for Acceptance of Requested Licensing Action Re: License Amendment Request Regarding General Design Criterion 5 of Appendix A to 10 CFR Part 50 and Regulatory Guide 1.81 (EPID L-2023-LLA-0058)" (ADAMS Accession Number ML23136B296)
- 3. Luminant letter from Jay Lloyd to U.S. NRC dated June 15, 2023, "Supplemental Information to Facilitate Acceptance of Licensee Amendment Request 23-002, Application Regarding GDC-5 Shared System Requirements" (ADAMS Accession Number ML23166B144)
Enclosure to TXX-23067 SUPPLEMENTAL REQUEST AND CPNPP RESPONSE
Enclosure to TXX-23067 Page 1 of 3 SUPPLEMENTAL REQUEST AND CPNPP RESPONSE NRC REQUEST INTRODUCTION By letter dated April 20, 2023 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23110A156, Vistra Operations Company LLC (Vistra OpCo, the licensee) submitted a license amendment request (LAR) for Comanche Peak Nuclear Power Plant (Comanche Peak, CPNPP), Unit Nos. 1 and 2, regarding changes to the Final Safety Analysis Report (FSAR). Specifically, the proposed amendments would allow a deviation in compliance to Regulatory Guide (RG) 1.81, Revision 1, Shared Emergency and Shutdown Electric Systems for Multi-Unit Nuclear Power Plants (ML003740343) to meet the regulatory requirements of Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Domestic Licensing of Production and Utilization Facilities, Appendix A, General Design Criteria for Nuclear Power Plants, General Design Criterion (GDC) 5, Sharing of structures, systems, and components, and address the violation issued in the Comanche Peak Integrated Inspection Report dated November 1, 2022 (ML22299A056). To support the proposed amendment, the licensee proposed FSAR changes to provide additional description of the power feeds to some common 125 volts direct current (VDC) and 118 volts alternating current (VAC) safety-related electrical buses, which can be fed from both units and also feeds some Unit 1 specific loads.
The licensee also submitted Technical Specifications (TSs) Bases changes (mark-up) necessary to account for changes in the FSAR.
The U.S. Nuclear Regulatory Commission (NRC) staff has identified that the following information is needed to begin its technical review.
REGULATORY REQUIREMENTS Appendix A, to 10 CFR Part 50, GDC 5, states that:
Structures, systems, and components important to safety [, including the onsite electric power supplies and distribution systems,] shall not be shared among nuclear power units unless it can be shown that such sharing will not significantly impair their ability to perform their safety functions, including, in the event of an accident in one unit, an orderly shutdown and cooldown of the remaining units.
The regulations in 10 CFR 50.36, Technical specifications, establish the requirements related to the content of the TS. Pursuant to 10 CFR 50.36(c), TS are required to include items in five specific categories related to station operation: (1) safety limits, limiting safety system settings, and limiting control settings, (2) limiting conditions for operation, (3) surveillance requirements, (4) design features; and (5) administrative controls.
The regulation, 10 CFR 50.36(a)(1), states that:
Each applicant for a license authorizing operation of a production or utilization facility shall include in his application proposed technical specifications in accordance with the requirements of this section. A summary statement of the bases or reasons for such specifications, other than those covering administrative controls, shall also be included in the application, but shall not become part of the technical specifications.
Enclosure to TXX-23067 Page 2 of 3 OTHER ISSUES IDENTIFIED DURING THE ACCEPTANCE REVIEW Although not required for the NRC to complete its acceptance review, the NRC staff has identified some initial information required to complete its review as follows. The response may be submitted with the responses to a supplemental request or separately (e.g., with responses to requests for additional information, if they are identified).
ISSUE 1 The TS Bases should reflect the design basis in the FSAR. TS Bases table B 3.8.9-1 does not currently list all the safety-related buses, including the common buses clarified in the LAR. The listing of all the safety-related buses in TS Bases table B 3.8.9-1 is considered necessary to meet the intent of TS 3.8.9.
Provide updated TS Bases table B 3.8.9-1 with additions of common 125 VDC buses XED1-1 and XED2-1, and common 118 VAC buses XEC1-1 and XEC2-1, to their train A and train B assignments. In addition, all other safety-related buses (such as 480 VAC motor control centers buses) to which safety-related loads are connected should also be added to table B 3.8.9-1.
RESPONSE
CPNPP is providing the following TS Bases page containing Table B 3.8.9-1 on page 3. The new table does now include bus XEC1-1 and bus XEC2-1, as requested by the NRC, to match the TS Bases requirements. However, CPNPP decided against adding in bus XED1-1, bus XED2-1, or any other safety-related bus, due to the requirements of 10CFR50.36(c)(2)(iii), "A licensee is not required to propose to modify technical specifications that are included in any license issued before August 18, 1995, to satisfy the criteria in paragraph
[10CFR50.36](c)(2)(ii)." Since both CPNPP Units received their Operating License before August 18, 1995, the station is not required to add new safety-related buses to the listing of required distribution buses merely because they meet one of the four criteria.
Enclosure to TXX-23067 Page 3 of 3 Distribution Systems - Operating B 3.8.9 Table B 3.8.9-1 (page 1 of 1)
AC and DC Electrical Power Distribution Systems TYPE VOLTAGE TRAIN A(1)(2)
TRAIN B(1)(2)
AC Safety Buses 6900 V 480 V ESF Bus 1EA1 (2EA1)
Load Centers 1EB1, 1EB3 (2EB1, 2EB3)
ESF Bus 1EA2 (2EA2)
Load Centers 1EB2, 1EB4 (2EB2, 2EB4)
DC Buses 125 V Bus 1ED1 (2ED1)
Bus 1ED3 (2ED3)
Bus 1ED2 (2ED2)
Bus 1ED4 (2ED4)
AC vital buses 118 V Buses 1EC1, 1EC5 (2EC1, 2EC5)
Buses 1PC1, 1PC3 (2PC1, 2PC3)
Bus XEC1-1(3)(4)
Buses 1EC2, 1EC6 (2EC2, 2EC6)
Buses 1PC2, 1PC4 (2PC2, 2PC4)
Bus XEC2-1(3)(4)
(1) Each train of the AC and DC electrical power distribution systems is a subsystem.
(2) The 480 V load centers are fed from the following transformers:
1EB1 - T1EB1 1EB2 - T1EB2 1EB3 - T1EB3 1EB4 - T1EB4 2EB1 - T2EB1 2EB2 - T2EB2 2EB3 - T2EB3 2EB4 - T2EB4 (3) When this bus is powered by Unit 2 in MODES 1-6, the bus is immediately considered INOPERABLE, and the requirements of TS 3.8.9, Condition B or TS 3.8.10, Condition A are applicable as appropriate for Unit 1 ONLY.
(4) When this bus is powered by Unit 1, the bus is not a required distribution bus for TS 3.8.9 or TS 3.8.10 purposes.