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Category:Meeting Briefing Package/Handouts
MONTHYEARML23275A1712023-10-16016 October 2023
October 16, 2023, Licensee Pre-submittal Meeting Slides - License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505-A, Revision 2 for Wolf Creek Generating Station
ML21333A1512021-11-29029 November 2021
Pre-Submittal Meeting Slides License Amendment Request Addressing Portable Lighting for Operator Manual Actions
ML21179A0892021-07-13013 July 2021
Background Information July 13, 2021, Pre-Submittal Public Teleconference
ML20308A7332020-11-18018 November 2020
Slides for GSI-191 Pre-Submittal Public Teleconference November 18, 2020
ML18299A0492018-10-30030 October 2018
Accident Analyses Methodology Transition LAR Public Meeting
IR 05000482/20174072017-12-22022 December 2017
Summary of Closed Regulatory Conference to Discuss Wolf Creek, Unit 1, Security Inspection Report 05000482/2017407
ML16271A4822016-09-27027 September 2016
Summary of Regulatory Conference to Discuss Safety Significance of Wolf Creek Generating Station Emergency Generator Excitation Diode Apparent Violation
ML16236A0952016-08-25025 August 2016
and Wolf Creek Generating Station - August 25, 2016, Class 1E Electrical Equipment Air Conditioning System Pre-Application Meeting
ML16095A0782016-04-12012 April 2016
Slides for the WCGS Meeting Discussion 4/12/16
ML16095A0852016-04-12012 April 2016
Large Scale Head Loss Test Specification 4/12/16
ML16095A0802016-04-12012 April 2016
Large Scale Penetration Test Specification 4/12/16
ML16095A0922016-03-31031 March 2016
Large Scale Penetration and Head Loss Test Plan 4/12/16
ML14188C4812014-07-0707 July 2014
Summary of Annual Assessment Meeting with Wolf Creek Generating Station
ML14134A1842014-05-14014 May 2014
Summary of Public Meeting to Discuss an Apparent Violation Identified at Wolf Creek Generating Station
ML14038A3852014-02-0606 February 2014
1/22/2014 - Summary of Public Meeting to Discuss Corrective Actions Implemented to Address the Chilling Effect Letter
ML13218A0212013-08-0707 August 2013
Licensee Slides, 08/07/13 Preapplication Meeting with Wolf Creek Nuclear Operating Corporation to Discuss Long-Term Corrective Actions for Water Hammer Events in the Essential Service Water System at Wolf Creek
ML13205A2142013-07-30030 July 2013
Operating Corporation - Slides for Pre-application Meeting on 7/30/13 - Core Design and Safety Analysis Methodology Transition License Amendment Request for Wolf Creek Generating Station
ML12263A3622012-09-20020 September 2012
Pre-application Meeting Slide Core Design and Safety Analysis Methodology Transition License Amendment Request TAC No. ME9495)
ML12191A1742012-07-0909 July 2012
6/25/2012 Summary of Public Meeting with Wolf Creek Nuclear Operating Corporation
ML1110104292011-04-11011 April 2011
Summary of Annual Performance Assessment Meeting with Wolf Creek Nuclear Operating Corporation to Discuss Wolf Creek Generating Station Performance for the NRC Inspection Period Ending December 31, 2010
ML1016204902010-06-16016 June 2010
Notice of Construction Reactor Oversight Process Category 2 Public Meeting Handout: Wolf Creek 2, Notice of Violation and Proposed Imposition of Civil Penalty, Dated 11/21/1984
ML1016901162010-06-16016 June 2010
6/16/2010 Construction Reactor Oversight Process Category 2 Public Meeting Handout: Meeting Slides (Enforcement Cases)
ML1013404892010-05-14014 May 2010
Summary of Annual Performance Assessment Meeting with Wolf Creek Nuclear Operating Corporation to Discuss the Wolf Creek Generating Station Performance for the NRC Inspection Period from January 1 Through December 31, 2009
ML0933702032009-12-0303 December 2009
Summary of Public Meeting for Wolf Creek Generating Station
ML0933801482009-11-20020 November 2009
Licensee Handouts from November 20, 2009, Public Meeting with Union Electric Company and Wolf Creek Nuclear Operating Company to Discuss GL 2004-02 Response Rai'S
ML0913300232009-05-13013 May 2009
Meeting Slides, Successful Licensing of the Als Fpga Based Safety Related I&C Platform
ML0912600692009-05-0606 May 2009
Lessons Learned Using Digital I&C Interim Staff Guidance Workshop
ML0902102422009-01-15015 January 2009
Licensee Slides, January 15, 2009, Category 1 Meeting with Wolf Creek Nuclear Operating Corporation to Discuss Changes to Post Fire Shutdown Unresolved Items Analysis Methods Pre-Application for Wolf Creek Generating Station
ML0834700222008-12-11011 December 2008
Slides, Category 2 Public Meeting Digital Instrumentation and Control Steering Committee
M080717, M080717-Commission Briefing Slides/Exhibits Briefing on Fire Protection2008-07-17017 July 2008
M080717-Commission Briefing Slides/Exhibits Briefing on Fire Protection
ML0817706682008-06-25025 June 2008
Summary of Meeting with Wolf Creek Nuclear Operating Corporation to Discuss Several Initiatives That Were Being Implemented to Improve Plant Performance at Wolf Creek
ML0803706102008-01-11011 January 2008
Westinghouse Electric Company LLC, LTR-CDME-08-2, Rev. 1 NP-Attachment, Meeting Handouts from the December 13, 2007 Meeting with Wolf Creek and NRR on H*/B*.
ML0729204682007-10-29029 October 2007
09/25/2007, Summary of Meeting Between the U.S. Nuclear Regulatory Commission Staff and Strategic Teaming and Resource Sharing Representatives to Discuss License Renewal Activities
ML0721501532007-08-0202 August 2007
NRC Staff Handout for August 2, 2007, Meeting with Wolf Creek Nuclear Operating Corporation
ML0721102382007-07-24024 July 2007
Performanc Contracting, Inc.'S Powerpoint Slide, Proposed Wolf Creek/Callaway Test Configuration
ML0719303772007-07-11011 July 2007
Handouts (NRC and Licensee) for Meeting with Representatives of Wolf Creek Nuclear Operating Corporation
ML0718606902007-06-19019 June 2007
06/19-20/2007 Slides,Fabrication Records Review, from Category 2 Public Meeting Between the NRC Staff and the Expert Panel for the Wolf Creek Advanced Finite Element Analyses (Fea)
ML0716203882007-06-0101 June 2007
06/01/07 - Presentation Material, Advanced Fea Crack Growth Calculations for Evaluation of PWR Pressurizer Nozzle Dissimilar Metal Weld Circumferential Pwscc.
ML0733409182007-05-31031 May 2007
05/31/2007 Presentation by J. Cudsworth NRC Treatment of Issues Other than Category 2 Issues for License Renewal
ML0713703642007-05-17017 May 2007
Handout for Meeting with Wolf Creek Nuclear Operating Corporation on the Licensee'S Application for the Main Steam and Feedwater Isolation System (Msfis) Modification
ML0713506532007-05-0808 May 2007
Slides, Recommendations for Critical Flaw Size Calculations (in Wolf Creek Advanced Fea Project).
ML0713506462007-05-0808 May 2007
Industry Slides, Advanced Fea Crack Growth Calculations for Evaluation of PWR Pressurizer Nozzle Dissimilar Metal Weld Circumferential PWSCC, from Status Meeting on Implications of Wolf Creek Dissimilar Metal Weld Inspections
ML0713506512007-05-0808 May 2007
Slides, Category 2 Public Meeting with NEI on the Implications of the Wolf Creek Dissimilar Metal Weld Inspections.
ML0713603732007-05-0101 May 2007
Enclosure-1 05/01/2007 Dominion Engineering Presentation Advanced Fea Crack Growth Calculations for Evaluation of PWR Pressurizer Nozzle Dissimilar Metal Weld Circumferential Pwscc.
ML0713603962007-05-0101 May 2007
Enclosure 2-05/01/2007 Engineering Mechanics Corporation of Columbus Presentation, NRC Welding Residual Stress Solutions as Generated by Battelle and Emc2.
ML0701704732007-01-19019 January 2007
12/19/2006 Summary of Public Meetings Related to the Review of the Wolf Creek Generating Station License Renewal Application
ML0635603632006-12-20020 December 2006
12/01/2006 Industry Meeting Handout: Draft Report (December 2006) - Implications of Wolf Creek Pressurizer Butt Weld Indications Relative to Safety Assessment and Inspection Requirements
ML0701601892006-12-19019 December 2006
12/19/2006, Viewgraphs from Meeting with Wolf Creek Generating Station to Discuss License Renewal Process and Environmental Scoping
ML0635603582006-11-30030 November 2006
Industry Presentation Slides: MRP-139 Analysis Basis
ML0635603462006-11-30030 November 2006
November 30, 2006 NRC Presentation Slides: Wolf Creek Flaw Evaluation
2023-10-16
[Table view]
Category:Slides and Viewgraphs
MONTHYEARML23275A1712023-10-16016 October 2023
October 16, 2023, Licensee Pre-submittal Meeting Slides - License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505-A, Revision 2 for Wolf Creek Generating Station
ML21333A1512021-11-29029 November 2021
Pre-Submittal Meeting Slides License Amendment Request Addressing Portable Lighting for Operator Manual Actions
ML20310A2232020-11-19019 November 2020
Slides for ERO Staffing pre-submittal Public Teleconference November 19, 2020 (L-2020-LRM-0104)
IR 05000482/20174072017-12-22022 December 2017
Summary of Closed Regulatory Conference to Discuss Wolf Creek, Unit 1, Security Inspection Report 05000482/2017407
ML16236A0952016-08-25025 August 2016
and Wolf Creek Generating Station - August 25, 2016, Class 1E Electrical Equipment Air Conditioning System Pre-Application Meeting
ML16236A0972016-08-25025 August 2016
Operating Corporation - August 25, 2016, Core Design and Safety System Analysis Methodology Transition License Amendment Request Revised
ML16095A0782016-04-12012 April 2016
Slides for the WCGS Meeting Discussion 4/12/16
ML14188C4812014-07-0707 July 2014
Summary of Annual Assessment Meeting with Wolf Creek Generating Station
ML14134A1842014-05-14014 May 2014
Summary of Public Meeting to Discuss an Apparent Violation Identified at Wolf Creek Generating Station
ML14038A3852014-02-0606 February 2014
1/22/2014 - Summary of Public Meeting to Discuss Corrective Actions Implemented to Address the Chilling Effect Letter
ML13218A0212013-08-0707 August 2013
Licensee Slides, 08/07/13 Preapplication Meeting with Wolf Creek Nuclear Operating Corporation to Discuss Long-Term Corrective Actions for Water Hammer Events in the Essential Service Water System at Wolf Creek
ML13219A1932013-08-0707 August 2013
Licensee Slides (Final), 08/07/13 Preapplication Meeting with Wolf Creek Nuclear Operating Corporation to Discuss Long-Term Corrective Actions for Water Hammer Events in the Essential Service Water System at Wolf Creek
ML13205A2142013-07-30030 July 2013
Operating Corporation - Slides for Pre-application Meeting on 7/30/13 - Core Design and Safety Analysis Methodology Transition License Amendment Request for Wolf Creek Generating Station
ML13121A4892013-05-0101 May 2013
End of Cycle Meeting Summary 4-18-13
ML12263A3622012-09-20020 September 2012
Pre-application Meeting Slide Core Design and Safety Analysis Methodology Transition License Amendment Request TAC No. ME9495)
ML12191A1742012-07-0909 July 2012
6/25/2012 Summary of Public Meeting with Wolf Creek Nuclear Operating Corporation
ML1110104292011-04-11011 April 2011
Summary of Annual Performance Assessment Meeting with Wolf Creek Nuclear Operating Corporation to Discuss Wolf Creek Generating Station Performance for the NRC Inspection Period Ending December 31, 2010
ML1016901162010-06-16016 June 2010
6/16/2010 Construction Reactor Oversight Process Category 2 Public Meeting Handout: Meeting Slides (Enforcement Cases)
ML1013404892010-05-14014 May 2010
Summary of Annual Performance Assessment Meeting with Wolf Creek Nuclear Operating Corporation to Discuss the Wolf Creek Generating Station Performance for the NRC Inspection Period from January 1 Through December 31, 2009
ML0933702032009-12-0303 December 2009
Summary of Public Meeting for Wolf Creek Generating Station
ML0933801482009-11-20020 November 2009
Licensee Handouts from November 20, 2009, Public Meeting with Union Electric Company and Wolf Creek Nuclear Operating Company to Discuss GL 2004-02 Response Rai'S
ML0913300232009-05-13013 May 2009
Meeting Slides, Successful Licensing of the Als Fpga Based Safety Related I&C Platform
ML0912600762009-05-0606 May 2009
Lessons Learned Using Digital I&C Interim Staff Guidance Workshop Application of ISG-4 During Wolf Creek and Oconee Reviews
ML0912600692009-05-0606 May 2009
Lessons Learned Using Digital I&C Interim Staff Guidance Workshop
ML0902102422009-01-15015 January 2009
Licensee Slides, January 15, 2009, Category 1 Meeting with Wolf Creek Nuclear Operating Corporation to Discuss Changes to Post Fire Shutdown Unresolved Items Analysis Methods Pre-Application for Wolf Creek Generating Station
ML0834700222008-12-11011 December 2008
Slides, Category 2 Public Meeting Digital Instrumentation and Control Steering Committee
M080717, M080717-Commission Briefing Slides/Exhibits Briefing on Fire Protection2008-07-17017 July 2008
M080717-Commission Briefing Slides/Exhibits Briefing on Fire Protection
ML0817706682008-06-25025 June 2008
Summary of Meeting with Wolf Creek Nuclear Operating Corporation to Discuss Several Initiatives That Were Being Implemented to Improve Plant Performance at Wolf Creek
ML0813606472008-06-10010 June 2008
05/01/2008-Summary of Public Meeting on Safety Evaluation Report with Open Items Regarding the Wolf Creek Generating Station License Renewal Review
ML0721102382007-07-24024 July 2007
Performanc Contracting, Inc.'S Powerpoint Slide, Proposed Wolf Creek/Callaway Test Configuration
ML0720601382007-07-17017 July 2007
Slides from Meeting Between NRC Staff and Wolf Creek Panel Enclosures 2 to 3, Advanced Fea Crack Growth Calculations for Evaluation of PWR Pressurizer Nozzle Dissimilar Metal Weld Circumferential Pwscc.
ML0719303772007-07-11011 July 2007
Handouts (NRC and Licensee) for Meeting with Representatives of Wolf Creek Nuclear Operating Corporation
ML0718606902007-06-19019 June 2007
06/19-20/2007 Slides,Fabrication Records Review, from Category 2 Public Meeting Between the NRC Staff and the Expert Panel for the Wolf Creek Advanced Finite Element Analyses (Fea)
ML0716203882007-06-0101 June 2007
06/01/07 - Presentation Material, Advanced Fea Crack Growth Calculations for Evaluation of PWR Pressurizer Nozzle Dissimilar Metal Weld Circumferential Pwscc.
ML0733409182007-05-31031 May 2007
05/31/2007 Presentation by J. Cudsworth NRC Treatment of Issues Other than Category 2 Issues for License Renewal
ML0713703642007-05-17017 May 2007
Handout for Meeting with Wolf Creek Nuclear Operating Corporation on the Licensee'S Application for the Main Steam and Feedwater Isolation System (Msfis) Modification
ML0713506512007-05-0808 May 2007
Slides, Category 2 Public Meeting with NEI on the Implications of the Wolf Creek Dissimilar Metal Weld Inspections.
ML0713506532007-05-0808 May 2007
Slides, Recommendations for Critical Flaw Size Calculations (in Wolf Creek Advanced Fea Project).
ML0713603732007-05-0101 May 2007
Enclosure-1 05/01/2007 Dominion Engineering Presentation Advanced Fea Crack Growth Calculations for Evaluation of PWR Pressurizer Nozzle Dissimilar Metal Weld Circumferential Pwscc.
ML0713603962007-05-0101 May 2007
Enclosure 2-05/01/2007 Engineering Mechanics Corporation of Columbus Presentation, NRC Welding Residual Stress Solutions as Generated by Battelle and Emc2.
ML0701601892006-12-19019 December 2006
12/19/2006, Viewgraphs from Meeting with Wolf Creek Generating Station to Discuss License Renewal Process and Environmental Scoping
ML0635603462006-11-30030 November 2006
November 30, 2006 NRC Presentation Slides: Wolf Creek Flaw Evaluation
ML0635603582006-11-30030 November 2006
Industry Presentation Slides: MRP-139 Analysis Basis
ML0632100802006-11-16016 November 2006
Industry Presentations: Nov. 16, 2006 Public Meeting
ML0632100772006-11-16016 November 2006
NRC Presentation: NRC Perspective on Wolf Creek Inspection Results
ML0622804372006-08-16016 August 2006
Handouts from Wolf Creek Nuclear Operating Corporation and from Union Electric Company for Meeting with NRC on the Main Steam Isolation Valve (MSIV) Operability Determination
ML0618000292006-06-28028 June 2006
Handout for June 28, 2006, Meeting with Representatives of Wolf Creek Nuclear Operating Corporation for Wolf Creek Generating Station on the Main Steam and Feedwater Isolation System (Msfis) Controls Replacement Project
ML0615106012006-05-23023 May 2006
EPRI HRA Users Group Review of Draft NUREG-1842
ML0617902332006-03-0808 March 2006
RIC 2006 Presentation - W3D - Maurice E. Dingler - GSI 191
ML0516705662005-06-16016 June 2005
Summary of Annual Performance Assessment Meeting with NRC Re Oversight Process and Safety Performance at Wolf Creek Generating Station
2023-10-16
[Table view] |
Text
MRP-139 Analysis Basis MRP / NRC November 30, 2006 Greg Kammerdeiner, First Energy Chairman, Assessment ITG
Purpose
- Provide overview of analysis documents that support required butt weld inspections in MRP-139
- Summarize the purpose, method and main conclusions from each document
- Review supporting analysis documents in light of Wolf Creek inspection findings
© 2006 Electric Power Research Institute, Inc. All rights reserved. 2
Roadmap to Butt Weld Analysis Documents
- Document preparation spanned five year period from June 2000 through August 2005
© 2006 Electric Power Research Institute, Inc. All rights reserved. 3
MRP-21: Crack Growth of A182 in PWRs
Purpose:
To determine crack growth rates in A182 weld metal used to join A600 CRDM nozzles to vessel heads
- Methodology: Sample welds prepared using typical materials and procedures were then tested in autoclave
Conclusions:
- The crack growth rates in A182 welds were up to five times higher than for A600
- A preliminary crack growth model was developed Superseded by MRP-115
© 2006 Electric Power Research Institute, Inc. All rights reserved. 4
MRP-44.1: Preliminary Butt Weld Safety Assessment
Purpose:
To prepare a preliminary safety assessment to address butt weld cracks such as occurred at Ringhals 3/4 and leak as occurred at VC Summer
- Methodology: Prepared a survey of A182 butt weld locations and assessed operating experience, crack orientation, flaw tolerance, leak detection, boric acid corrosion, and structural margin
Conclusions:
- Plants have adequate margin to continue operation
- Identified short-term inspection guidance Superseded by MRP-113
© 2006 Electric Power Research Institute, Inc. All rights reserved. 5
MRP-57: A182 Experience in BWRs
Purpose:
To assess A182 butt weld cracks in BWR plants
- Methodology: GE reviewed public and proprietary crack data
Conclusions:
- There are more axial cracks than circumferential cracks
- Axial cracks can grow long if not arrested by resistant material
- Circumferential cracks were all less than 90º arc length (and some deep) except Duane Arnold
- 360º crack at Duane Arnold caused by crevice environment not present in PWRs. Nevertheless, showed leak before rupture
© 2006 Electric Power Research Institute, Inc. All rights reserved. 6
MRP-33: RPV Nozzle Weld Stresses
Purpose:
To determine effect of weld geometry (single vs double V) and repairs on residual stresses to help understand Ringhals 3/4 and VC Summer cracks/leak
- Methodology: Prepared elastic-plastic finite element models of welds and repairs
- Hoop stresses exceed axial stresses at ID surface such that most cracks should be axial
- Through-wall hoop stresses are high suggesting potential for rapid crack growth
- Welds finished on the ID, or repaired on the ID, have high tensile stresses on inside surface
© 2006 Electric Power Research Institute, Inc. All rights reserved. 7
MRP-106: Residual and Operating Stresses in A182 Butt Welds
Purpose:
To determine residual/operating stresses for full range of butt weld sizes (1 to 30) and ID repairs for larger (5 to 30) butt welds
- Methodology: Elastic-plastic finite element analyses for multi-pass welds and 30º, 60º, and 90º partial-arc ID repairs
Conclusions:
- For normal welds without repairs, tensile stresses at ID are low, consistent with small number of cracks/leaks
- Weld repairs to the ID create high tensile hoop and axial stresses of similar magnitude
- Many butt welds too small for ID repairs
- Adding weld deposit to OD can reduce ID tensile stress
© 2006 Electric Power Research Institute, Inc. All rights reserved. 8
MRP-109: Safety Assessment for Westinghouse and CE Plant Butt Welds
Purpose:
To assess safety of A182 butt welds in Westinghouse and CE plants
- Size of critical axial and circumferential flaws,
- Time for cracks to grow through wall and circumferentially using generic residual stresses and MRP-21 crack growth model, and
- Potential to detect leaks before rupture
Conclusions:
- Axial flaws not a concern due to crack arrest at carbon and SS material
- Times for partial-arc cracks to grow through-wall can be <1 yr
- Time between leak detection and rupture >2 yr
© 2006 Electric Power Research Institute, Inc. All rights reserved. 9
MRP-112: Safety Assessment for B&W Design Plants
Purpose:
To assess safety of A182 butt welds in B&W design plants
- Methodology: Essentially the same as MRP-109 since Westinghouse and Framatome collaborated on analysis methodology
Conclusions:
- Axial flaws not a concern
- Time for part-arc cracks to grow thru-wall can be <4 yr
- Some time between detectable leakage and rupture except for PZR relief nozzle
© 2006 Electric Power Research Institute, Inc. All rights reserved. 10
MRP-114: Effect of Weld Repairs
Purpose:
To assess the effect of partial-arc weld repairs on circumferential cracking
- Methodology: Fracture mechanics crack growth calculations based on:
- As-welded and repaired residual stresses in MRP-106,
- PVP-365 K algorithm (superposition method) and
- Crack arrests for K < 0
Conclusions:
- Regions of high crack growth are limited to approximately the arc length of the weld repair region
- Even for cases of 360º ID repairs, uniform initiation is highly unlikely (i.e., Duane Arnold)
© 2006 Electric Power Research Institute, Inc. All rights reserved. 11
MRP-116: Probabilistic Risk Assessment
Purpose:
To assess the probability and consequences of rupture of butt welds due to PWSCC
- Methodology: Probabilistic model based on standard Westinghouse approach considering crack initiation, crack growth, crack detection, leakage detection, rupture and core damage
Conclusions:
- Probability of leak due to axial crack is 2 orders of magnitude higher than for circ cracks
- Total risk (CDF or LREF) within Reg. Guide 1.174 guidelines for 40 year plant life
© 2006 Electric Power Research Institute, Inc. All rights reserved. 12
MRP-115: A82/182 Crack Growth Rates
Purpose:
To develop A82/182 crack growth model considering worldwide data
- Methodology: All available data collected and screened by panel of international experts, including NRC and NRC contractors
Conclusions:
- Recommended deterministic curve at 75th percentile of data
- MRP-115 curve for A182 similar to MRP-21 but with no stress intensity threshold
- Curve for A82 between A600 base metal and A182 weld metal (closer to A600)
© 2006 Electric Power Research Institute, Inc. All rights reserved. 13
MRP-113: Final Butt Weld Safety Assessment
Purpose:
To integrate all MRP safety assessment work into one overall summary document
- Methodology: Same as described for other reports
Conclusions:
- Most cracks expected to be axial and will arrest at carbon and SS material
- Deep partial-arc circ cracks should be limited to region of weld repairs with leak detection before rupture except at one location
- 360º part-depth circ cracks unlikely to occur
- BMVs should be performed within next two outages
- Inspection plan is being developed
© 2006 Electric Power Research Institute, Inc. All rights reserved. 14
MRP-139: Butt Weld Inspection Requirements
Purpose:
To develop mandatory inspection intervals for A82/182 butt welds
- Methodology: Inspection intervals based on MRP-113 and BWRVIP approach
Conclusions:
- Characterize all weld profiles by end of 2007
- Inspect PZR welds by end of 2007
- Inspect HL welds 4-14 NPS by end of 2008
- Inspect HL welds >14 NPS by end of 2009
- Inspect CL welds by end of 2010
- MRP Letter 2004-05 requires BMV of welds by 2007
© 2006 Electric Power Research Institute, Inc. All rights reserved. 15
Review Based on Wolf Creek Inspections
- MRP-113/114 address partial-arc circ cracks caused by weld repairs
- Repairs known to be detrimental with potential for circumferential flaws
- Crack growth rate can be high
- Crack growth limited to approximate repaired region
- Unknown to what extent WC indications align with repairs
- Critical flaw size is large
- 144-166º for safety/relief from existing analyses
- Realistically much larger (remove SSE and thermal loads)
- Maximum Wolf Creek flaw is estimated at 26% thru-wall and 155º extent.
- Depth vs arc length is unknown
- Palisades and Duane Arnold confirm margin for large circumferential flaws
© 2006 Electric Power Research Institute, Inc. All rights reserved. 16
Opportunities for Improvement
- Establish less conservative critical flaw size
- Better estimate of K vs crack depth with stress relaxation
- Probabilistic considerations
© 2006 Electric Power Research Institute, Inc. All rights reserved. 17
