ML21271A202

Pre-Submittal Meeting on October 5, 2021 - Hatch NFPA 805 Supplement LAR (SNC Slides)

ML21271A202
Person / Time
Site:	Hatch
Issue date:	10/05/2021
From:	Southern Nuclear Operating Co
To:	John Lamb NRC/NRR/DORL/LPL2-1
Lamb J
References
Download: ML21271A202 (15)

Text

Hatch Pre-Submittal Meeting NFPA 805 LAR Attachment S2, Table S-2 Changes

October 5, 2021 Meeting Purpose

• Discuss proposed license amendment request (LAR) to revise Attachment S2, Table S-2, Plant Modifications Committed, of SNC letter NL-19-1475 referenced in the NFPA 805 Fire Protection Transition License Condition.

• Provide a summary of the changes to Attachment S2, Table S-2.

2 Meeting Agenda

• Background and Reason for Proposed Change

• LAR Summary Description

• Description of Proposed Change

• Modification Implementation Schedule

3 Background and Reason for Proposed Change Background and Reason for Proposed Change

• NRC approved NFPA 805 License Amendment Request in June 2020

• Table S-2 listed modifications needed to achieve NFPA 805 compliance

• Required items listed in Table S-2 to be implemented within 2 refueling outages after issuance of the Safety Evaluation (Unit 1 by 1R31 (2024) and Unit 2 by 2R27 (2023))

• Safety Evaluation required NFPA 805 Program Implementation Table S-3 items be implemented by June 2021. NFPA 805 Program Implementation was completed in June of 2021.

5 Background and Reason for Proposed Change (continued)

• During implementation of the NFPA 805 Program requirements, necessary changes to Attachment S2, Table S-2 were identified:

• Additional breaker coordination evaluations were performed for all Nuclear Safety Capability Assessment (NSCA) / Fire Probabilistic Risk Assessment (FPRA) power supplies which identified additional NFPA 805 breaker coordination modifications.

• Extent of condition reviews were also performed which identified the need for additional engineering evaluation and potential modification of two motor-operated valves (MOVs).

• Field verifications identified the need for installation of three additional cable tray covers.

• Implementation of Attachment S2, Table S-2, Item 14, Fire Damper modification identified the need to clarify that fire testing would be performed to bound the as installed fire damper configurations.

6 LAR Summary Description LAR Summary Description

• Revision to NFPA 805 LAR Attachment S2, Table S-2 to reflect additional modifications associated with breaker coordination, cable tray covers, IN 92-18 issues*, and clarification to the scope of fire damper resolution.

• Revised Unit 1 and Unit 2 Facility Operating License Transition License Condition will reference updated Table S-2 that will be provided in LAR.

• Timeframe for transition to full compliance (by the startup of the second refueling outage (for each unit) after the original NRC SE) unchanged.

• As will be discussed later in presentation, SNC still determining whether modifications to MOVs will be required.

8 Description of Proposed Change Proposed Changes

• Breaker Coordination Modifications

• An evaluation was performed of the credited FPRA and NSCA power supplies to ensure breaker coordination had been adequately addressed for each panel.

• The evaluation identified that two additional NSCA power supplies did not meet the requirements of the LAR Attachment B, NEI 04-02 Table B-2 NSCA Methodology Review. Modifications have been identified to comply with the breaker coordination criteria.

• The evaluation also identified that nine additional FPRA power supplies require breaker coordination modification.

• In accordance with the Transition License Condition, non-conforming power supplies credited in the FPRA were evaluated to demonstrate whether they have no more than a minimal risk impact to FPRA.

• SNC considers a delta risk < 1E-08 core damage frequency and < 1E-09 large early release frequency to be no more than a minimal risk impact.

10 Proposed Changes

• Cable Tray Cover Modification

• The FPRA credits cable tray covers in specific locations to reduce the propagation of fire.

• Walkdowns during the NFPA 805 Fire Protection Program Implementation identified three locations where the as found configuration did not agree with the FPRA.

• Compensatory measures have been implemented for these locations until the modifications are complete.

11 Proposed Changes

• IN 92-18 MOV Modification

• Two additional MOVs credited by the FPRA have been identified as being susceptible to a hot short which could by-pass the limit and torque switches.

• Additional engineering evaluations are in progress to determine if the potential fault could result in a loss of pressure boundary.

12 Proposed Changes

• Fire Damper Modification

• LAR Attachment S2, Table S-2, Item 14 identifies that certain fire damper configurations in the plant do not meet the NFPA 90A code requirements related to the installation in accordance with the condition of approval.

• A clarification in the proposed resolution is being requested to identify that condition of approval includes performing additional fire testing of the damper configurations to bound existing damper configurations or modify the dampers to meet fire test results.

13 Modification Implementation Schedule

• The NFPA 805 Transition License Condition schedule for completion of the NFPA 805 modifications remains unchanged with these additional modifications.

• Unit 1 Modifications complete by 1R31 (2024)

• Unit 2 Modifications complete by 2R27 (2023)

14 Questions?