ML18254A253

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COL Docs - Presentation for September 13, 2018 Pre-Submittal Meeting on SNC LAR-18-023 - Public Version (NON-PROPRIETARY)
ML18254A253
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Site: Vogtle  Southern Nuclear icon.png
Issue date: 09/11/2018
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Download: ML18254A253 (10)
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Vogtle PEmails From: Hoellman, Jordan Sent: Tuesday, September 11, 2018 12:10 PM To: Vogtle PEmails

Subject:

Presentation for September 13, 2018 Pre-Submittal Meeting on SNC LAR-18-023 -

PUBLIC VERSION (NON-PROPRIETARY)

Attachments: LAR-18-023_Common Q Watchdog Timers_PSM Slides_PUBLIC version.pdf The attached presentation will be used for the September 13th Pre-Submittal Meeting for SNC LAR-18-023, Request for License Amendment: Protection and Safety Monitoring System Watchdog Timer and Common Q Design Description Changes.

This version of the presentation does not contain proprietary information and may be provided to the Public. The non-Public (i.e., Proprietary) version of this presentation was provided in a separate email.

1

Hearing Identifier: Vogtle_COL_Docs_Public Email Number: 364 Mail Envelope Properties (SN6PR0901MB2366DAD6AAD25E6112E1D915D5040)

Subject:

Presentation for September 13, 2018 Pre-Submittal Meeting on SNC LAR-18-023 - PUBLIC VERSION (NON-PROPRIETARY)

Sent Date: 9/11/2018 12:09:38 PM Received Date: 9/11/2018 12:09:49 PM From: Hoellman, Jordan Created By: Jordan.Hoellman2@nrc.gov Recipients:

"Vogtle PEmails" <Vogtle.PEmails@nrc.gov>

Tracking Status: None Post Office: SN6PR0901MB2366.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 467 9/11/2018 12:09:49 PM LAR-18-023_Common Q Watchdog Timers_PSM Slides_PUBLIC version.pdf 785499 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received:

VEGP 3&4 LAR-18-023 (WEC LAR-213):

Protection and Safety Monitoring System Watchdog Timer and Common Q Design Description Changes September 13, 2018 (PUBLIC version) 1

Meeting Purpose and Agenda Meeting Purpose

  • Pre-submittal meeting to discuss the proposed change in VEGP 3&4 LAR-18-023, Protection and Safety Monitoring System (PMS) Watchdog Timer and Common Q Design Description Changes
  • Proactively engage Staff in preparation of preliminary amendment request (PAR)

Agenda

  • Background Information
  • Summary of Changes
  • Discussion of PAR 2

Background Information

  • NSAL 17-2, AC160 Processor Module Stall Timers Not Activated as Described in Licensing Basis

- Software stall timer within the AC160 software is not enabled as per WCAP-16097-P-A, Rev. 3, Common Q Topical Report (TR)

- A cycle time in the Common Q TR does not meet as-built system

  • Extent of condition identified additional changes to WCAP-16097
  • Discussed condition with NRC in 2017

- Part 21 Report concluded there is no safety impact or operational impact

  • Stall timers do not perform a safety-related function
  • Fault would have been detected by other means
  • Window watchdog timers and relay are activated as expected

- Draft changes to Common Q TR presented 3

Background Information SNC LAR-18-023 - PMS Watchdog Timer and Common Q Description

  • Revises the UFSAR to accurately describe the design and use of the watchdog timers (WDTs) in the processor module of the Common Q platform portion of the protection and safety monitoring system (PMS)

- LAR Section 2 provides an overview of the PMS and CQ platform

  • Includes Common Q major building blocks of Fault Detection
  • WDTs - self-testing diagnostic features of the AC160 controller
  • Also changes the design description of the Common Q platform

- Changes identified in Extent of Condition review for NSAL 17-2

- Presented in LAR Sections 2.1.3 - 2.6

  • Westinghouse plans to submit generic changes to the Common Q topical report at a later date 4

Licensing Basis Document Changes

  • Tier 2* Changes

- Revision 3 was approved by NRC Safety Evaluation dated 2/7/13

- VEGP 3&4 Amendment Nos. 79 (U3) and 78 (U4) [ML17104A109]

- Licensing basis revised to refer to WCAP-16097-P/NP-A, Rev. 3, as modified by process alternatives in WCAP-15927, Rev. 6

  • WCAP-15927, Design Process for Common Q Safety Systems

- Changes provided as Tier 2* mark-ups, rather than entire WCAP

- WCAP-15927, Rev. 6 was provided with ND-17-0439 [ML17076A410]

- Revise Section 3.10 and Table 3-2 to include Design Alternatives

  • Tier 2 Changes
  • Conforming references to WCAP-15927 in UFSAR Table 1.6-1, Appendix 1A, and Section 7A.7 (WCAP-16674-P-A, AP1000 I&C Data Communication and Manual Control of Safety Systems and Components) 5

Technical Evaluation

  • Delete Description of the [ ] a.c
  • There are no PMS requirements that credit the [ ]a,c
  • The AP1000 PMS has other mitigations to protect against a stalled processor; upon detection of an internal processor module fault, the [ ]a,c will put the PMS in a safe state.
  • Westinghouse has qualified the [ ]a,c for this purpose, as discussed in the closure of Common Q Topical Report Generic Open Item 7.3 (see WCAP-16097-P-A, Rev. 0 and Rev. 3 Generic OIs [ML030550776] and the Common Q summary qualification report).
  • Correction of Watchdog Timeout Window
  • It was determined that the (approximate) 3 millisecond difference in detecting internal faults is negligible.
  • Change has no adverse impact on the safety function of the processor modules.

The safety function and operability of the processor module is not adversely impacted by this change.

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Technical Evaluation

  • Changes to the Design Description of the Common Q Platform
  • SYSDia Test Timer Correction (LAR Section 2.2)
  • Revise Description of AC160 System Software Execution Location (LAR Section 2.3)
  • Processor Communication Section Memory Capacity Change (LAR Section 2.4)
  • Change to Description of when the Overload (OVERL) Terminal is set to TRUE (LAR Section 2.5)
  • Delete Description of the Processor Module [ ]a,c (LAR Section 2.6)
  • Conforming Administrative Changes (LAR Section 2.7)

- Removal of Duplicate Information from WCAP-16675 (LAR Section 2.1.3)

  • Each change is evaluated individually in the identified LAR sections
  • Overall conclusion is consistent with conclusion reached for WDTs:

The safety function and operability of the processor module is not adversely impacted by this change.

7

PAR

  • A PAR is planned to be submitted concurrently to allow installation (at-risk) of cabinets and panels in the Protection and Safety Monitoring System (PMS) that are impacted by the proposed changes.

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