ML18254A253
| ML18254A253 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 09/11/2018 |
| From: | NRC |
| To: | NRC/NRO/DLSE/LB4 |
| References | |
| Download: ML18254A253 (10) | |
Text
1 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.
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:
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"Vogtle PEmails" <Vogtle.PEmails@nrc.gov>
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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:
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1 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)
2 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
3 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
4 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
5 Licensing Basis Document Changes
- Tier 2* Changes
- WCAP-16097-P-A, Common Q Platform Topical Report, Rev. 3 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
- UFSAR Section 7A.8 (WCAP-16675-P-A, AP1000 PMS Architecture Technical Report)
- 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)
6 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.
7 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.
8 PAR