ML17004A049

Southern Nuclear - Vogtle 50.69 Enhancement Submittal Public Meeting Slides

ML17004A049
Person / Time
Site:	Vogtle
Issue date:	01/04/2017
From:	Southern Nuclear Operating Co
To:	Michael Orenak Plant Licensing Branch II
Orenak M
References
Download: ML17004A049 (9)

Text

Vogtle 50.69 Enhancement Submittal

• Background

• Previous Review scopes

• Intentions of this submittal

• Seismic PRA model

• Peer Review Facts and Observations (F&Os)

• SPRA Adequacy 2

Vogtle 50.69 Background

• SNC requested pilot status 50.69 - Dec. 2010

• NRC granted VEGP pilot status - June 2011

• SNC 50.69 LAR submitted - Aug. 2012

• NRC approved VEGP 10 CFR 50.69 - Dec. 2014

• NRC 50.69 inspection - June 13- 30, 2016

• Inspection report provided to SNC Aug. 10, 2016

- NO FINDINGS 3

Scope of Enhancement Submittal

• Replace Seismic Margins Approach with SPRA model insights

• No other changes to the currently approved risk categorization program RISC 1 RISC 2 Safety Related Non Safety Related High Safety High Safety Significance Significance Safety Related Non Safety Related Low Safety Low Safety Significance Significance RISC 3 RISC 4 RISC = Risk Informed Safety Class 4

Operating License Conditions Note: Unit 1 shown. Unit 2 is identical. See Amendment 155 5

Currently Approved Risk Categorization Tools

• Internal events PRA for internal risk

• Fire PRA for fire risk

• Seismic margin analysis for seismic risk <Update to SPRA>

- Low risk contributor compared to other tools

• Individual Plant Examination of External Events (IPEEE) screening to asses risk from other external hazards (high winds external floods)

• Safety Plan to assess shutdown risk 6

Options to Address Contributions AREAS TO ADDRESS Internal Fire Seismic Other Shutdown Events Risk Risk Risk External Risk Events Risk O Internal Events Other P (including Seismic External Shutdown PRA PRA T Internal Fire Events PRA Flooding) PRA I PRA O Updated Updated S/D DID N FIVE Seismic IPEEE Model via SSEL Screening EOOS S (SMA) 7

Seismic PRA Model

• High Quality SPRA model

- PWROG Peer Review conducted November 2014

- All F&Os have been dispositioned

• All SRs met at CC II per Addendum B of ASME/ANS Seismic PRA Standard

- Sources of model uncertainty 8

Summary

• Long history of VEGP investment in 50.69

• 50.69 process has been extensively reviewed

• Intentions of this submittal

• NRC acceptance of SPRA in the Approved 50.69 Categorization process

• High quality Peer Reviewed model

• One aspect in the determination of safety significance in the Categorization process 9