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 Safety Related High Safety Significance Non Safety Related High Safety Significance Non Safety Related Low Safety Significance Safety Related Low Safety Significance RISC 1 RISC 2 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 Fire PRA Seismic PRA Internal Events Risk Fire Risk Seismic Risk Other External Events Risk Shutdown Risk Updated Seismic SSEL (SMA)

Other External Events PRA Updated IPEEE Screening Shutdown PRA S/D DID Model via EOOS Internal Events (including Internal Flooding)

PRA FIVE O

P T

I O

N S

AREAS TO ADDRESS 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