ML022760399

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Firstenergy Nuclear Operating Co., & Bnfl Westinghouse Electric Co., LLC, Meeting on Risk-Informed In-service Inspection(Is) Augmented High Energy Line Break (HELB)
ML022760399
Person / Time
Site: Beaver Valley
Issue date: 09/25/2002
From:
FirstEnergy Nuclear Operating Co, Westinghouse
To:
Office of Nuclear Reactor Regulation
References
Download: ML022760399 (22)
v • d • e


Text

xt e : 1,111111.191.. I I I I mill FENOC Beaver Valley 2-NRC-WOG Meeting On Risk-informed In-service Inspection (ISi)

Augmented High Energy Line Break

"(HELB)

September 25, 2002 02002 FirstEnergy Nuclear Operating Company

©2002 Westinghouse Electric Company LLC 9/25/02 1

Agenda I

I I I mill

- History

- Lead Plant, Scope, and Approach

- Results

- NRC Review e Related WOG Risk-Informed Initiatives

  • Summary 9/25/02 2

( -

Introduction I I MENMHH m~il Introduction and Opening Remarks To discuss and to obtain NRC feedback and direction on program results on the extension of the risk-informed ISI application to High Energy (HE) piping in the Break Exclusion Zone (BEZ) at FirstEnergy Nuclear Operating Company Beaver Valley Unit 2 the lead plant for the WOG Topical Report Addendum 9/25/02 3

eI I I I mllI Risk Informed Methods Applied to High Energy Line Break Augmented Inspections WCAP-14572 Revision 1-NP-A Addendum 1 - Markup 9/25/02 4 4

--- iN

History I1

"* WCAP 14572 Rev 1-NP-A Addendum 1 submitted 12/99 for augmented exams and HELB specifically

"* March 8, 2000 WOG/NRC met to address and discuss NRC questions (ADAMS ML0036900235) on the Addendum to WCAP-1 4572, Revision 1-NP-A for augmented exams and HELB specifically

"* Markup to Addendum 1 of WCAP-1 4572, Rev 1-NP-A issued to NRC 6/2000

"* Beaver Valley-2 identified to NRC to test methodology for HELB exams

"* Meeting held between NRC/NEI/WOG/EPRI in May 2001;

- NRC expressed concern about consequence analysis that would be used to address HELB exams for break exclusion regions,' particularly where 100% selection per SRP or NUREG-0800 is required to meet GDC-4 intent

- NRC concerned about portioris of high energy pipingcurrently covered by augmented ISI where a break would violate single failure criteria, e.g., there is no way to isolate the failure of some main steam piping outside containment

- Treatment of dynamic effects from pipe failure must be consistent with NRC Standard Review Plan Chaptei"3.6.2

- Notification proposed to be done via periodic §50.59 summary report and SAR update per §50.71(e)

Meeting held September 2001 between NRC/FENOC/WOG presenting results of application of WCAP 14572 Methodology for Lead Plant Scope, Segment Definition, Direct Consequence Assessment, and Indirect Effects Assessment tasks.

Meeting held between NRC/NEI/WOG/EPRI in October 2001; technical issues and regulatory approach discussed.

- Confirmed process for notification via §50.59 summary report and SAR update per §50.71(e) 9/25/02 5

Lead Plant, Scope, and Approach I I mHlI

- FirstEnergy Corporation Beaver Valley Unit 2 (FENOC BV2)

  • Scope

- RI-ISI Base Program ASME Class 1/Class 2 RI-ISI Piping

- BV2 High Energy (HE) Piping in the Break Exclusion Zone (BEZ) as defined in the UFSAR Base-001 BEZ-001 p.-

Service Inside p.-

BEZ-002 Reactor L

.-- ý -. _j Service Containment Valve Main Steam Valve Room Building

-d Break Exclusion Zone (BEZ) 9/25/02 6

't ý- ?

Lead Plant, Scope, an(J Approach

  • V *s 9 WEEN111I Approach

- WOG RI-ISI Methodology defined in Addendum to WCAP-1 4572, Revision 1 NP-A dated May 2000

- Identical to WOG Risk-Informed In-Service Inspection Methodology defined in WOAP-14572 ReVision 1-NP-A

- Documentation process and requirements identical to base scope

- Safety concerns and regulatory oversight addressed via well-defined assessment process (1 OCFR50.59) 9/25/02 7

Results e~e eq :.ee. I I I IIIII

  • Scope and Segment Definition

- HE piping identified using UFSAR system list and plant piping line list

- 16 segments added to base scope segments

- 917 Base Scope Class 1 and 2 piping segments

- 933 Total segments considered in evaluation

- No additional segments defined as a result of indirect consequences 9/25/02 8

Results eI - 9 I I roN1!1 Consequence Evaluation

- Direct

- Indirect

"* A walkthrough per WOG RI-ISI Methodology defined in addendum to WCAP-14572 Revision 1-NP-A (May 2000) was completed for all BEZ piping inside and outside of containment

"* Walkthroughs confirmed existing Design Basis documentation

"* Design Basis Break Locations exist at penetrations inside containment.

"* Penetration Design consistent inside and outside containment.

"* Potential new pipe breaks in the BEZ have designs in place to mitigate consequences in adjacent areas

  • Existing plant design reflects train separation

"* Systems required to perform safety related functions concurrently or consecutively were physically isolated

"* Current inspection locations have isolated or redundant impacts on safety in the event of a piping failure

  • To date no flaw indications found within BEZ scope segments

- Evaluated through plant PRA 9/25/02 9

Results ezýnl  : 9 I mI

  • Failure Probability Assessment - WinSRRA used to assess piping failure probability
  • Risk Evaluation

- Segment combinations considered

  • 917 Base scope (Class 1 and 2 piping)
  • 933 segments in combined scope (Class 1, Class 2, and BEZ)
  • 72 BEZ segments (56 Base Scope/BEZ and 16 BEZ only)
  • Evaluated with no credit for non-BEZ augmented inspection program

- 933 segments in combined scope (Class 1, Class 2, and BEZ)

- 72 BEZ segments

- Relative ranking of segments did not vary as a result of combination considered

- Importance of segments did not vary as a result of combination considered 9/25/02 10

Results e e  :

I I I I lmH~g

,Risk Results Summary Segment Combination CDF LERF With Op. Action Without Op. Action With Op. Action Without Op. Action Base Scope (917 Segments) 1.36E-06 1.90E-06 2.15E-08 2.33E-08 Base + BEZ (933 Segments) 1.36E-06 1.90E-06 2.15E-08 2.33E-08 BEZ (72 Segments) 1.07E-1 0 9.93E-11 2.62E-12 1.46E-12 9/25/02 11

Results I I II I m L'i/guy gin mAmLW*L*hj III Expert Panel Categorization

- Panel Members consistent with Base Scope Review

- Significant discussion on potential indirect effects due to flooding, etc.

confirmed indirect effects assessment completed as part of standard methodology application.

- No change to base scope HSS/LSS rankings Base Scope Base/BEZ Scope 107 HSS Segments 107 HSS Segments 807 LSS Segments 823 LSS Segments 3 Not Used Segments 3 Not Used Segments

- 16 BEZ, which are non-Class 1/2 segments, all ranked LSS

- 8 segments ranked HSS during Base Scope Class 1/2 effort are part of BEZ pipe scope 9/25/02 12

4 Results e e  : - 9. I mml~I Structural Element/Non-Destructive Examination (NDE) Selection Program Exams Reduction Current Section XI 586 NA Base Scope 88 85%

Base Sc ope and Augmented BEZ 320 NA Base Scope and RI-ISI BEZ 88 72%

Program. Exams Current BEZ 240, NA RI-ISI BEZ 8 96%

9/25/02 13

Results 0'Trio9.

I I IIIII

  • Change in Risk - Base Scope program conclusions remain applicable

- 4 Piping Class 2 Segments added for inspection (2 RCS and 2 SIS)

- Reduction in overall plant risk Change In Risk Results Summary Segment Combination CDF LERF With Op. Action Without Op. Action With Op. Action Without Op. Action Section XM 2.81 E-07 8.24E-07 4.52E-09 6.41 E-09 Base Scope (917 Segments) 2.73E-07 8.02E-07 4.36E-09 6.32E-09 Base + BEZ (933 Segments) 2.73E-07 8.02E-07 4.36E-09 6.32E-09 Section Xl BEZ Segments 1.17E-10 1.11E-10 2.85E-12 2.OOE-12 RI-ISI BEZ Segments 1.17E-10 1.11E-10 2.85E-12 2.OOE-12

'4" *'*"

NRC Review Schedule eE - .

I I MEmNEII

  • Beaver Valley

- Base Scope Submittal

  • Provided to NRC in July 2002 e Approval Requested for February 2003 to support Spring 2003 Outage

- 10CFR50.59

  • Completion needed by February 2003 to support Spring 2003 Outage

- Need by December 2002 9/25/02 15

eI . I I I mHlI Related WOG Risk-Informed Initiatives 9/25/02 16

WOG Risk-Informed ISI Subgroup 11111

  • Two day training session held on the WOG RI-ISI Process on June 19 & 20, 2002
  • Working with EPRI and NEI on developing a. "White Paper" on the Living Program for RI-ISI
  • To ensure consistent application of the WOG RI-ISI methodology, the Subgroup expects to start peer evaluations of RI-ISI programs in 2003
  • Investigating applicationof risk-informed methods to leakage and analytical evaluation
  • Developed a process for conducting inquiries for interpretation of WCAP-14572 9/25/02 17

Risk-Informed Repair &

Replacement

"* Provided support to the development and approval of ASME Code Cases N-658 and N-660

- Tested Code Case N-658 as part of Option 2 pilot program at Surry Unit 1 and Wolf Creek

- Incorporated both RI-ISI methodologies into the ASME repair/replacement application

- Code Cases approved by ASME in July/August 2002

"* Demonstration showed that many Class 2 and 3 pressure retaining items may be categorized as low safety significant; some non-Code Class items may be high safety significant

"* Working with WOG on developing first applications 9/25/02 18

'V

.V .

Risk-Informing 10CFR50 Special Treatment Requirements - Option 2 0 e: So9 IN MINE I

"* Performed WOG Option 2 Pilot Program

- Applied to 2 systems at 2 plants (Wolf Creek/Surry)

- Tested NEI Guidance (NEI-00-04) and ASME Code Case N-658

- Developed cost/benefit evaluation (submitted to NEI and NRC)

"* Provided feedback to NEI on industry guidance and to ASME on Code Case

  • Provided feedback through NEI and ASME to NRC on proposed 50.69 rule
  • Continuing to follow progress of industry guidance and NRC rulemaking 9/25/02 19

Option 3 - LBLOCA I I I I mill

"* Initiating Frequencies

"*Petition for Rulemaking Submitted 9/25/02 20

Reactor Vessel In-Service Inspection Interval Extension

  • Joint CEOG-WOG Program

- Initial feasibility evaluations completed

- Program aligned with PTS efforts

- Pilot plants identified

- Draft Code Case and White Paper presented at Sept 2002 ASME Section XI meetings

- ASME Review comments requested by October 11, 2002

- Revised Code Case/White Paper presentation planned for December 2002 9/25/02 21

Summary

  • Beaver Valley Unit 2 BEZ application completed
  • WOG requests SER to be provided on outstanding WCAP Addendum Report
  • WOG continuing to support several beneficial risk-informed initiatives with industry, NRC and ASME 9/25/02 22

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