ML063450068

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12/5/06 Public Meeting Handout from Entergy/Epri Re GGNS Application of N-716
ML063450068
Person / Time
Site: Grand Gulf  Entergy icon.png
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)
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Text

Entergy In conjunction with II F~r2I ELECTRIC POWER 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

@ 2006 Electric Power Research Institute, Inc. All rights reserved.

Introduction 1994-1997 1998-1999 1999-Present Code Case N-560 -

Class-1 BJ Welds Only Code Case N-577 -

RI-ISI Method A Code Case N-578 -

RI-ISI Method B NRC Approves Industry Reports -

U.S. & Worldwide Industry Implement -

WOG Topical R]

ISI Method A EPRI Topical RI-ISI Method B

> 20 U.S. Reactors +

Several Countries OM

>60 U.S. Reactors +

Several countries I2I EETIC POE

© 2006 Electric Power Research Institute, Inc. All rights reserved.

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 11jRt AP 5

i51 UTE

=

Background===

  • Number of high safety significant (HSS) locations added by plant review VY = zero ANO-1 = zero ANO-2 = zero Fitzpatrick = zero South Texas 1 & 2 = zero BWR-N-560 B&W-N-560 CE - N-578 (full scope)

BWR - N-578 (full scope)

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 EjECTRIC POER

© 2006 Electric Power Research Institute, Inc. All rights reserved.

5

1 Background

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 Implementation via 50.59 procedure 2006 Electric Power Research Institute, Inc. All rights reserved.

6$t RESEARCH 1S9TITtTLITE

=

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

© 2006 Electric Power Research Institute, Inc. All rights reserved.

7I

=

Background===

Recent Experiences (RI-ISI Submittals)

- Results of USNRC Review

" Plant

  • Plant

" Plant

  • Plant

" Plant A-70 B-40 C-40 D-17 E-13 locations locations locations locations locations added added added added added ELECTRIC POWER C-:f=fal I RESEARCH INSTITME

© 2006 Electric Power Research Institute, Inc. All rights reserved.

=

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

@ 2006 Electric Power Research Institute, Inc. All rights reserved, 9

8 I RF A ý'Cit INS'TITUTE

=

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

©2006 Electric Power Research Institute, Inc. All rights reserved.

10 RE SEARCH INSTITUJTE

=

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 ELETRI 2tPOWER

©9 2006 Electric Power Research Institute, Inc. All rights reserved.

11CE2I j R~SACH1145lTLJUTE

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

© EELECTRIC POWER

©2006 Electric Power Research Institute, Inc. All rights reserved.

12 ez

~

a RE"5ARtCH INSrTITUTE

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 Feedwater from SIGs to BER Segments with > IE-6 CDF (from internal flooding 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

©2006 Electric Power Research Institute, Inc. All rights reserved.

14 a

f fa RESEAR~CH INSTITUTE

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 E LECTRIC POWER R ESEARCH INST11UTIF

© 2006 Electric Power Research Institute, Inc. All rights reserved.

15

GGNS Results J

N-716 Safety Significance Determination

System Description

Weld N-716 Safety Significance Determination Safety Significance 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 190 i

NA ELECTRIC POWER RESEARCH INSTITUTE

© 2006 Electric Power Research Institute, Inc. All rights reserved.

16

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 RESEARCH VNI15TITUTE

© 2006 Electric Power Research Institute, Inc. All rights reserved.

17

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 E LECTINC POV.IR (E(f2IjEtRH NMT

© 2006 Electric Power Research Institute, Inc. All rights reserved.

18

GGNS Results 1

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

Safety Significance Break Location Failure Potential Code Weld Section Xl I Code Case N-716 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

1 0

0 RPV LOCA TT, (IGSCC)

Medium (Medium)

B-J 1

1 0

0 B-J 1

1 0

0 B-F 20 20 0

0 RPV LOCA None (IGSCC)

Low (Medium)

B-J 6

6 0

0 B-F 1

1 0

0 RPV LOCA None Low 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

© 2006 Electric Power Research Institute, Inc. All rights reserved.

KKURK POWER U5115ARCH 1145TITUTE 19

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 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 af=fal I RE$EAKKiK5TI1UTE

© 2006 Electric Power Research Institute, Inc. All rights reserved.

20

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 High Low DMs Rank Category Count IVol/Sur Sur Only1 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

REEAC 11N5TITUTE

© 2006 Electric Power Research Institute, Inc. All rights reserved.

21

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 E1LE2T K POWER

© 2006 Electric Power Research Institute, Inc. All rights reserved.

22

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

Safety Significance Break Location Failure Potential Code Weld Section XI Code Case N-716 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

© 2006 Electric Power Research Institute, Inc. All rights reserved.

23 Et ' -.TRIC POWER CEF121 I R I ; ' KH I NST'ITVP

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 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

© 2006 Electric Power Research Institute, Inc. All rights reserved.

24 RESEAKNC 1I*TI1TME

N-716 / RIS_B Summary Founded upon previously conducted work:

" Deterministic approaches

" Qualitative risk approaches

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

© 2006 Electric Power Research Institute, Inc. All rights reserved.

25 RESEVCH INS-FrITLTE

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)

© 2006 Electric Power Research Institute, Inc. All rights reserved.

26 i

RESEARC ISTITUTIE

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