Text

12/5/06 Public Meeting Handout from Entergy/Epri Re GGNS Application of N-716
	ML063450068
Person / Time
Site:	Grand Gulf
Issue date:	12/05/2006
From:	; Electric Power Research Institute, Entergy Operations
To:	Bhalchandra Vaidya; NRC/NRR/ADRO/DORL/LPLIV
	Vaidya B, NRR/DORL/LP4, 415-3308
References
	TAC MD3044
	Download: ML063450068 (26)
	v • d • e

Entergy In conjunction with ELECTRIC POWER F~r2I II RESEARCH INSTITUTE Grand Gulf I Application of N-716 I December 5, 2006

Introductions

" Background

" N-716 e Grand Gulf Results

" Lessons Learned

" Summary/Conclusions

8I7R!2I PWE IR

Introduction 1994-1997 1998-1999 1999-Present Code Case N-560 - NRC Approves U.S. & Worldwide Industry Class-1 BJ Welds Only Industry Reports - Implement -

Code Case N-577 - WOG Topical R] > 20 U.S. Reactors +

RI-ISI Method A ISI Method A Several Countries Code Case N-578 - EPRI Topical RI- OM >60 U.S. Reactors +

RI-ISI Method B ISI Method B Several countries

Introduction N-716 Risk-Informed / Safety Based ISI (RISB)

Purpose:

Develop a streamlined process for RI-ISI programs

Standardized methodology

" Provides stability to the process

Improved oversight (licensee, industry, and regulatory) 2006 Electric Power Research Institute, Inc. All rights reserved. 4 AP i515 UTE 11jRt

Background

Number of high safety significant (HSS) locations added by plant review

- VY = zero BWR-N-560

- ANO-1 = zero B&W-N-560

- ANO-2 = zero CE - N-578 (full scope)

- Fitzpatrick = zero BWR - N-578 (full scope)

- South Texas 1 & 2 = zero West - N-560

Number of HSS locations added by NRC review

- VY = zero

- ANO-1 = zero

- ANO-2 = zero

- Fitzpatrick = zero

- South Texas 1 & 2 = zero

1Background

RI- Break Exclusion Requirements (HELB)

- EPRI TR-1006937

" Approved June 2002

NRC Review

- Inspection population < 10 percent

- Implementation via 50.59 procedure

- WCAP-14572, Addendum 1

" Approved March 2004

NRC Review

- Inspection population < 10 percent

Background

Code Case N-663 "Alternative Surface Examination Requirements"

- Incorporates lessons learned from RI-ISI methodology and applications

- Eliminates many unnecessary examinations

- Reduces worker exposures

- Minimal analysis cost (as compared to typical RI-ISI applications)

- A number of plants approved to date

Background

Recent Experiences (RI-ISI Submittals)

- Results of USNRC Review

" Plant A-70 locations added

Plant B-40 locations added

" Plant C-40 locations added

Plant D-17 locations added

" Plant E-13 locations added ELECTRIC POWER

Background

Recent Experiences (cont.)

RI-ISI Program Updates

" Plant A PRA model updates

- Physical plant changes (e.g. power uprate, S/G replacement)

- No change in HSS

- No change in inspection program

" Plant B

- PRA model updates

- Minor physical plant changes

- ~80 segments moved from Low to High/Medium

- -30 segments moved from High to Low

Background

Recent Experiences (cont.)

NEI 04-05 Update Review Eight Plants Updated with some resulting in a larger than expected change in inspection population:

- Four had no changes to the RI-ISl selections / inspections

- One had six exams eliminated and one added

- One had twenty exams eliminated and five added

- One had twenty eight exams eliminated and seven added

- One had nineteen exams eliminated 2 c r I , r sELKTRIC POWER

Background

Summary

RI-ISI methodologies.

- Some applications approved with no changes required

- Some applications approved after significant changes requested by the NRC

- Some applications are experiencing difficulty in gaining USNRC approval (e.g. numerous RAIs, re-analysis, changes to program, etc.)

Current program maintenance

- Burden associated with program updates

- Updates challenge program stability

1 N-716 / RIS_B GOAL: Develop a consistent and streamlined process for developing, implementing, and maintaining a RI-ISI program ASME Whitepaper 2002-02-01

Reviewed over fifty plant-specific RI-ISI applications,

Thirty, of which, were Class 1 & 2 or full scope applications

° Reviewed a number of industry and USNRC risk assessments Delta risk assessment conducted for eight plants

" Included both BWRs and PWRs,

Included plants that used the N-577/N-578 RI-ISI methods

N-716 typically increases the number of examinations compared to other RI-ISI methodologies

Does not credit the positive impact of N-716 Section 2(a)(5)

(i.e. CDF > 1E-06)

N-716 (RISB) provides a risk reduction or at worst, risk neutrality

N-716 /RIS B

" High Safety Significant (HSS)

Reactor Coolant Pressure Boundary (e.g. Class 1)

Shutdown Decay Heat Removal (out to containment isolation)

Break Exclusion Region (BER)

- Main Feedwaterfrom SIGs to BER

- Segments with > IE-6 CDF (from internalflooding study)

" Low Safety Significant (LSS)

- Remaining items (i.e.

" other Class 2,

" all Class 3,

all NNS 2006 Electric Power Research Institute, Inc. All rights reserved. 13 r I -"l RESEARCH INSTITUTE

N-716 RIS_B Examination Requirements

HSS population equal to 10%, plus augmented programs e HSS welds selected as follows:

- A minimum of 25 percent of the population identified as susceptible to each degradation mechanism and degradation mechanism combination

- RCPB, at least two thirds of the examinations shall be located between the first isolation valve (i.e., isolation valve closest to the RPV) and the reactor pressure vessel.

- A minimum of ten percent of the welds in that portion of the RCPB that lies outside containment (e.g., portions of the main feedwater system in BWRs) shall be selected.

- A minimum of ten percent of the welds within the break exclusion region shall be selected.

©rs t l sELECT RC POWER

N-716 / RIS B Additional Requirements

- Risk assessment of internal flooding events (flooding, pipe whip, spray, etc.)

- Augmented inspection programs for FAC, IGSCC-BWRs, PWSCC-PWRs, and localized corrosion (HSS

& LSS Systems)

- Delta risk per EPRI TR- 112657 15 LECTRIC POWER RESEARCH E INST11UTIF

GGNS Results

, J N-716 Safety Significance Determination Weld N-716 Safety Significance Determination Safety Significance

System Description

ICount RCPB SDC PWR: FW BER CDF > 1E-6 High Low RPV - Reactor Pressure Vessel (B13) 40 " NA /

FW- Feedwater (B21) 16 V V NA V ,

57 , V NA /

8 , NA V /

27 NA / /

MS - Main Steam (B21) 79 -" NA V 94 V NA ,

20 NA V "

SD - Steam Drains (B21) 5 V NA "

36 V NA "

SP - Sodium Pentaborate (B21) 5 , NA V RCR - Reactor Recirculation (B33) 4 V V NA i

190 NA ELECTRIC POWER

GGNS Results N-716 Safety Significance Determination S Weld N-716 Safety Significance Determination Safety Significance System Description. Count RCPB SDC PWR: FW BER CDF > 1E-6 High Low CRD - Control Rod Drive (Cl1) 63 NA /

SLC - Standby Liquid Control (C41) 42 V NA "

RHR - Residual Heat Removal (E12) 9 V NA 70 V NA /

35 NA V V 500 NA V LPCS - Low Pressure Core Spray (E21) 32 V NA ,

64 NA HPCS - High Pressure Core Spray (E22) 42 V NA V 82 NA V MSLC - Main Steam Leakage Control (E32) 31 V NA V V FWLC - Feedwater Leakage Control (E38) 11 " NA V ELEORK POWER

GGNS Results N-716 Safety Significance Determination Weld N-716 Safety Significance Determination Safety Significance System Description Count RCPB SDC PWR: FW BER CDF > 1E-6 High Low RCIC - Reactor Core Isolation Cooling (E51) 6 / NA V V 6 / NA V 12 NA V V 107 NA V CGC - Combustible Gas Control (E61) 8 NA /

RWCU - Reactor Water Cleanup (G33) 55 / NA " /

42 / NA V 34 NA V V 2 NA ,

SUMMARY

RESULTS FOR ALL SYSTEMS 16 / V NA V ,

70 " V NA "

184 " NA " V 610 " NA V 128 NA V ,

826 NA V TOTALS 1834 1008 826 ELECTINC POV.IR

GGNS Results 1

Inspection Location Selection Comparison Between ASME Section XI Code and Code Case N-716 Break Location Failure Potential ' Code Weld Section Xl I Code Case N-716 System(l) Safety Significance High Low DMs Rank Category Count Vol/Sur Sur Only RISB Other(2)

RPV V LOCA TASCS, TT, (IGSCC) Medium (Medium) B-F 6 6 0 4(3) -

B-F 1 11 00 00 --

LOCA TT, (IGSCC) Medium (Medium) B-J 1 RPV B-J 1 1 0 0 -

B-F 20 20 0 0 -

LOCA None (IGSCC) Low (Medium)

RPV B-J 6 6 0 0 -

B-F 1 1 0 0 -

LOCA None Low RPV B-J 5 5 0 0 -

FW V LOCA TASCS, TV Medium B-J 60 18 0 9 -

FW V ILOCA TASCS, TT Medium B-J 10 8 2 7 -

FW V BER TASCS, TT Medium C-F-2 10 1 0 3 -

FW V ILOCA TASCS Medium B-J 4 0 4 4 -

FW V LOCA TT Medium B-J 3 2 0 3 -

FW , ILOCA None Low B-J 4 0 1 0 -

FW V BER None Low C-F-2 17 1 0 0 -

KKURK POWER

GGNS Results Inspection Location Selection Comparison Between ASME Section XI Code and Code Case N-716 1 Break Location Failure Potential Code Weld Section XI Code Case N-716 System( ) Safety Significance High Low DMs Rank I Vol/Sur ISur Only RISB IOther(2)

MS - LOCA None Low B-J 107 9 4 4 -

MS V ILOCA None Low B-J 64 8 34 0 -

MS " PLOCA None Low B-J 2 0 2 0 -

MS V BER None Low C-F-2 20 2 0 0 -

SD " LOCA None Low B-J 37 0 4 4 -

SD / ILOCA None Low B-J 4 0 0 0 -

SP / LOCA None Low B-J 5 0 0 1 -

RCR V LOCA None (IGSCC) Low (Medium) B-J 25 6 0 8(4) -

RCR / LOCA None Low B-J 161 38 4 12 -

RCR V PLOCA None Low B-J 8 0 4 0 -

ELECTRK POWER

GGNS Results Inspection Location Selection Comparison Between ASME Section XI Code and Code Case N-716 System(1) Safety Significance Break Location Failure Potential Code Weld Section XI Code Case N-716 1

High Low DMs Rank Category Count IVol/Sur Sur Only RISB I Other(2)

CR0D v Class 2 N/A Assume Medium C-F-2 63 5 0 0 -

SLC V LOCA None Low B-J 5 0 0 4 -

SLC I PLOCA None Low B-J 37 0 4 1 -

RHR , BER TT, CC Medium C-F-2 4 0 0 1 -

RHR v, BER TT Medium C-F-2 13 4 0 4 -

RHR " LOCA None Low B-J 24 8 0 7 -

RHR I PLOCA None Low B-J 55 10 0 1 -

RHR V, BER None Low C-F-2 18 3 0 0 -

RHR , Class 2 N/A Assume Medium C-F-2 500 32 2 0 -

LPCS " LOCA None Low B-J 7 4 0 3 -

LPCS I PLOCA None Low B-J 25 4 0 1 -

LPCS / Class 2 N/A Assume Medium C-F-2 64 5 0 0 -

GGNS Results Inspection Location Selection Comparison Between ASME Section XI Code and Code Case N-716 System(

11 Safety Significance Break Location [ Failure Potential Code Weld Section XI Code Case N-716 High Low j DMs Rank Category Count [Vol/Sur Sur Onlyj RISB Other2')

HPCS LOCA TT Medium B-J 4 3 0 2 -

HPCS LOCA None Low B6J 8 3 1 2 -

HPCS V PLOCA None Low B-J 30 2 0 1 -

HPCS v" Class 2 N/A Assume Medium C-F-2 82 6 0 0 -

MSLC - ILOCA None Low B-J 31 0 1 4 -

FWLC " PLOCA None Low B-J 11 0 0 2 -

RCIC I LOCA None Low B-J 7 0 0 2 -

RCIC " PLOCA None Low B-J 5 0 0 1 -

RCIC " BER None Low C-F-2 12 5 0 0 -

RCIC / Class 2 N/A Assume Medium C-F-2 107 4 0 0 -

C-F-1 3 3 0 0 -

CGC " Class 2 N/A Assume Medium C-F-2 5 0 0 0 -

GGNS Results Inspection Location Selection Comparison Between ASME Section XI Code and Code Case N-716 Break Location Failure Potential Code Weld Section XI Code Case N-716 Safety Significance System(

High Low DMs ] Rank Category Count Vol/Sur Sur Only RISB Other(2)

RWCU V LOCA None Low B-J 65 11 1 10 -

RWCU ILOCA None Low B-J 25 8 0 2 -

B-J 4 0 0 0 -

C-F-2 22 2 0 0 -

RWCU V BER None Low Class 3 11 0 0 2 -

Other 1 0 0 .0 -

RWCU V Class 2 None Low B-J (5) 3 0 0 0 -

RWCU , Class 2 N/A Assume Medium C-F-2 2 0 0 0 -

Et ' -.TRIC POWER

N-716 / RIS_B Lessons Learned - Pilot plants Application of approved RI-BER process results in inspection populations less than required by N-716.

Application of approved RI-ISI for the RCPB results in inspection populations less than required by N-716.

2(a)(5) Requirement:

Plant 1 - internal flooding study did not identify piping > 1E-06

" Plant 2 - procedural/ hardware changes reduced CDF to < 1 E-06

Plant 3 - updated analysis to remove excessive conservatism to reduce CDF contribution to < 1 E-06

N-716 / RIS_B Summary

- Founded upon previously conducted work:

" Deterministic approaches

" Qualitative risk approaches

Quantitative risk approaches (WCAP-14572, EPRI TR-1 12657, EPRI TR-1006937, N-663)

- Uses generic insights to:

Assure defense in depth is maintained (i.e. high consequence sites, minimum inspection population)

Ensure that minor PRA changes do not cause unnecessary changes to the ISI Program.

Improve efficiencies for implementation and maintenance

- Uses plant-specific insights to:

Assure important plant specific inspections are conducted

" Maintain or improve pressure boundary reliability (e.g. degradation mechanisms)

- Requirement for augmented programs for PWSCC, IGSCC, FAC, LC

Conclusions N-716 Risk-Informed I Safety Based ISI (RISB)

Developed a streamlined process for RI-ISI programs

Standardized methodology

" Provides stability to the process

" Improved oversight (licensee, industry, and regulatory)

v t e Letter Sequence Meeting
TAC:MD3044, (Open)
Initiation Acceptance Administration Meeting, Meeting, Meeting, Meeting, Meeting, Meeting Questions Answers 23 May 2007 2 July 2007 27 August 2007 12 April 2007 12 April 2007 12 April 2007 Results Approval... Other: ML072430005
MONTHYEAR2007-04-25 [Table View]

ML063450068

Text

Introductions

Purpose:

Background

1Background

Background

Background

Background

Background

Background

System Description

SUMMARY

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