ML15335A302

Official Exhibit - NRC000207-00-BD01 - Regulatory Information Conference Presentation Slides, Recent Materials Inspections of PWR Reactor Internals (Mar. 2015)

ML15335A302
Person / Time
Site:	Indian Point
Issue date:	08/10/2015
From:	NRC/OGC
To:
SECY RAS
References
RAS 28141, ASLBP 07-858-03-LR-BD01, 50-247-LR, 50-286-LR
Download: ML15335A302 (10)

Text

© 2015Electric Power Research Institute, Inc. All rights reserved.

Glenn Gardner, DominionChair, Reactor Internals Working GroupNRC RIC Meeting March 2015 Recent Materials Inspections of PWR Reactor Internals 2© 2015Electric Power Research Institute, Inc. All rights reserved.

TopicsQuick Overview of MRP-227-A Inspections ApproachReactor Internals Inspection Results to DateObservations 3© 2015Electric Power Research Institute, Inc. All rights reserved.

Basic Approach of GuidelinesCombine detection of aging effects with focus on safety functionCredit and coordinate with existing ASME Code

inspectionsManage less active mechanisms by sampling, expand to additional scope based on resultsMake the inspection consis tent with component and its safety function 4© 2015Electric Power Research Institute, Inc. All rights reserved.

Basic Approach of GuidelinesConvey most requirements via simple tablesEnsure guideline is generally applicable to all PWRsNeeded and Mandatory requirements applicable to all US PWRs through NEI 03-08 initiativeMake the guideline a living document through reporting of results, review and update processEngineering evaluation of relevant conditions guided by companion document, WCAP-17096, developed by

PWROG5© 2015Electric Power Research Institute, Inc. All rights reserved.

Development and Evolution of MRP-227Four major stakeholders influenced development under NEI 03-08

-Owners, NRC, EPRI, NSSS VendorsExtensive interaction among stakeholders during developmentImplementation began in 2009 and continues each outage seasonResults to date show no unexpected issuesMRP-227 continues as a living documentEarly Beginning2003-2008MRP-227Rev. 0December, 2008MRP-227Rev. 0 SENovember 2011MRP-227-ADecember 2011MRP-227Rev. 1Target Sept 2015MRP-227Rev. 1 SETarget July, 2017MRP-227Rev. 1-A6© 2015Electric Power Research Institute, Inc. All rights reserved.B&W MRP-227-ARV Internals Primary ScopeLower Core Barrel Bolts (UT)Baffle-to-Former Bolts (UT)Flow Distributor Bolts (UT)Plenum Cover Weldment Rib Pads Support Flange and Core Support Shield Top Flange (VT3)Core Support Shield Vent Valve Top & Bottom Retaining Rings (VT-3)Upper Core Barrel Bolt Locking Devices/Welds (VT-3) Lower Core Barrel Bolt Locking Devices/Welds (VT-3) Baffle Plates (VT-3)Baffle-to-Former Bolt Locking Devices/Welds (VT-3)Internal Baffle-to-Baffle Bolt Locking Devices/Welds (VT-3)Flow Distributor Bolt Locking Devices (VT-3)Alloy X-750 Dowel-to-Guide Block Welds (VT-3)Incore Monitoring Guide Tube Spiders & Lower Grid Rib Welds (VT-3)Control Rod Guide Tube Spacer Castings and Cap Screws (VT-3) 7© 2015Electric Power Research Institute, Inc. All rights reserved.CE MRP-227-A RV Internals Primary ScopeCore Shroud Bolts (Bolted Design) (UT)Core Shroud Plate-Former Plate (Welded Design) (EVT-1)Welded Shroud Plates (Full Height Design) (EVT-1)Core Shroud Assembly [Bolted (VT-3); Welded (VT-1)]Core Barrel Upper Flange Weld (EVT-1)Core Barrel Lower Cylinder Girth Welds (EVT-1)Core Support Column Welds (VT-3)Core Barrel Lower Flange (TLAA or EVT-1)Core Support Plate (TLAA or EVT-1)Fuel Alignment Plate (Full Height Design) (TLAA or EVT-1)Instrument Guide Tubes (in CEA Shroud Design) (VT-3)Lower Structure Beams (Full Height Design) (EVT-1) 8© 2015Electric Power Research Institute, Inc. All rights reserved.Westinghouse MR-227-A Primary ScopeControl Rod Guide Card wear inspections (VT-3)Lower Control Rod Guide Tube (CRGT) Lower Flange welds (EVT-1)Baffle Former Bolts (UT)Baffle Former Assembly (including seams) (VT-3)Baffle Former Edge Bolts (VT-3)Upper Core Barrel Flange to Shell Weld (EVT-1)Lower Core Barrel Flange Weld (EVT-1)Thermal Shield Flexures (VT-3)Core Barrel Cylinder Girth Welds (EVT-1)Internals Hold-Down Spring (if applicable material type)

(measurement) 9© 2015Electric Power Research Institute, Inc. All rights reserved.Examples of Inspected Components 10© 2015Electric Power Research Institute, Inc. All rights reserved.

WLower CRGT Flange Welds 11© 2015Electric Power Research Institute, Inc. All rights reserved.Thermal Shield Flexures (VT-3) 12© 2015Electric Power Research Institute, Inc. All rights reserved.

VT-3/Measurement WControl Rod Guide CardsAcceptableObserved Wear 13© 2015Electric Power Research Institute, Inc. All rights reserved.VT-3of B&W Control Rod Guide Tube (CRGT) Spacer Castings and Cap Screws 14© 2015Electric Power Research Institute, Inc. All rights reserved.Baffle-Former Assembly Bolts Internal Hex External Hex 15© 2015Electric Power Research Institute, Inc. All rights reserved.B&W Lower Barrel and Flow Distributor Bolts 16© 2015Electric Power Research Institute, Inc. All rights reserved.Core Barrel WeldsNeutron Panel and lower girth weld 17© 2015Electric Power Research Institute, Inc. All rights reserved.

Inspection Implementation 18© 2015Electric Power Research Institute, Inc. All rights reserved.

Inspection Implementation

-Some inspections best performed with core barrel in vessel

-Others require core barrel removal

-Common to split inspections over two or more outages

-Typically integrated with ASME Section XI exams

-Special tooling often required

-Vendor crew of roughly 20 specialists required 24/7

-Vendor crew typically experienced on both PWRs and BWRs-Owner oversight 19© 2015Electric Power Research Institute, Inc. All rights reserved.

Inspection Results 20© 2015Electric Power Research Institute, Inc. All rights reserved.Inspections by Plant Design -as of Fall 2014DesignInitial OpsBfl BltsCB BoltsCRGT SpcBMI SpdrBW19732012F2012F2012F2012FBW19732013S2013S2013S2013SBW19742014S2014S2014S2014S3 of 6 totalBfl BltsCRGT WldsCB WldsGd CardsLCSCE19712014S2014S2014S2014S1 of 12 totalBfl BltsCRGT WldsCB WldsGd CardsW219692011S2011S2011S2011SW219702013S2013S2013S2013SW219732014S2014S2014S W219742014F2014F W219742013F W319702013F2013F2012S W319722010F2012S2013F2012SW319722014S W319732011S2012S2014S2012SW319732014F 11 of 48 total 21© 2015Electric Power Research Institute, Inc. All rights reserved.

Results to DateInitial full inspections at W and B&W and partial CE NSSS designs have not identified any major issues of concernCurrent results reduce uncertainty in mechanism activityIssues of greatest concern not seen

-SCC of austenitic welded components not observedCracking currently limited to high strength bolting

-IASCC of welds not observed, indications limited to bolts

-Macroscopic effect of void swelling not observed 22© 2015Electric Power Research Institute, Inc. All rights reserved.By the Numbers

• 15units begun or co mpleted MRP inspections 959W guide tube flange welds inspected2427inches of irradiated welds inspected (approx.)9125inches of non-irradiated weldsinspected (approx.)2226CASS items inspected8887baffle bolts UT inspected**1654B&W high strength bolts UT inspected**108 B&W baffle plates inspected

• All numbers approximate. Includes r eported inspections through Fall 2014; some data includes retired plant; additional data may affect results slightly

• • Includes retired unit 23© 2015Electric Power Research Institute, Inc. All rights reserved.By the Numbers

• Zero Guide Tube Flange weld indicationsZero irradiated girth weld indicationsOne non-irradiated weld indicationOne CASS VT-3 indication136 baffle bolt indications (1.5% of total)20 B&W high strength bolt indications (1.2% of total)

• All numbers approximate. Includes reported inspections through Fall 2014 ; additional data may affect results slightly 24© 2015Electric Power Research Institute, Inc. All rights reserved.

Trends and ObservationsAlmost no observed austenitic SS stress corrosion cracking (one indication reported)Irradiation Assisted SCC is extremely limited

-Currently limited to bolts

-Explained in part by irradiation stress relaxation

-High barrier to initiation in PWR environment

-Compared to other plant designs, major benefit from coolant chemistry 25© 2015Electric Power Research Institute, Inc. All rights reserved.

Trends and ObservationsNo macroscopic effects of void swelling

-No distortions, cracking, or excessive bolting failureHigh-strength nickel alloy clevis insert bolting failures

-However, not in safety function load pathGuide card wear will require monitoring

-MRP Interim guidance MRP-2014-006 issued 26© 2015Electric Power Research Institute, Inc. All rights reserved.

Trends and ObservationsSampling approach to inspections very successful

-Spectrum of plant designs, materials, heats

-Transition to more focused sampling for guide cardsEfficiency could be increased, and is being pursuedIntegrated fleet management strategies are possible 27© 2015Electric Power Research Institute, Inc. All rights reserved.

MRP-227-A Experience SummaryExam results show few instances of service-induced degradation flaws, as expectedOverall uncertainty in aging mechanism activity reduced Implementation by owners is thorough, but exams are difficult, as well as resource and dose intensiveSome adjustments and efficiencies are needed, as expected with a 'living' programLessons learned incorporated into MRP-227 Rev. 1 28© 2015Electric Power Research Institute, Inc. All rights reserved.

Together-Shaping the Futur e of Electricity

© 2015Electric Power Research Institute, Inc. All rights reserved.

Glenn Gardner, DominionChair, Reactor Internals Working GroupNRC RIC Meeting March 2015 Recent Materials Inspections of PWR Reactor Internals 2© 2015Electric Power Research Institute, Inc. All rights reserved.

TopicsQuick Overview of MRP-227-A Inspections ApproachReactor Internals Inspection Results to DateObservations 3© 2015Electric Power Research Institute, Inc. All rights reserved.

Basic Approach of GuidelinesCombine detection of aging effects with focus on safety functionCredit and coordinate with existing ASME Code

inspectionsManage less active mechanisms by sampling, expand to additional scope based on resultsMake the inspection consis tent with component and its safety function 4© 2015Electric Power Research Institute, Inc. All rights reserved.

Basic Approach of GuidelinesConvey most requirements via simple tablesEnsure guideline is generally applicable to all PWRsNeeded and Mandatory requirements applicable to all US PWRs through NEI 03-08 initiativeMake the guideline a living document through reporting of results, review and update processEngineering evaluation of relevant conditions guided by companion document, WCAP-17096, developed by

PWROG5© 2015Electric Power Research Institute, Inc. All rights reserved.

Development and Evolution of MRP-227Four major stakeholders influenced development under NEI 03-08

-Owners, NRC, EPRI, NSSS VendorsExtensive interaction among stakeholders during developmentImplementation began in 2009 and continues each outage seasonResults to date show no unexpected issuesMRP-227 continues as a living documentEarly Beginning2003-2008MRP-227Rev. 0December, 2008MRP-227Rev. 0 SENovember 2011MRP-227-ADecember 2011MRP-227Rev. 1Target Sept 2015MRP-227Rev. 1 SETarget July, 2017MRP-227Rev. 1-A6© 2015Electric Power Research Institute, Inc. All rights reserved.B&W MRP-227-ARV Internals Primary ScopeLower Core Barrel Bolts (UT)Baffle-to-Former Bolts (UT)Flow Distributor Bolts (UT)Plenum Cover Weldment Rib Pads Support Flange and Core Support Shield Top Flange (VT3)Core Support Shield Vent Valve Top & Bottom Retaining Rings (VT-3)Upper Core Barrel Bolt Locking Devices/Welds (VT-3) Lower Core Barrel Bolt Locking Devices/Welds (VT-3) Baffle Plates (VT-3)Baffle-to-Former Bolt Locking Devices/Welds (VT-3)Internal Baffle-to-Baffle Bolt Locking Devices/Welds (VT-3)Flow Distributor Bolt Locking Devices (VT-3)Alloy X-750 Dowel-to-Guide Block Welds (VT-3)Incore Monitoring Guide Tube Spiders & Lower Grid Rib Welds (VT-3)Control Rod Guide Tube Spacer Castings and Cap Screws (VT-3) 7© 2015Electric Power Research Institute, Inc. All rights reserved.CE MRP-227-A RV Internals Primary ScopeCore Shroud Bolts (Bolted Design) (UT)Core Shroud Plate-Former Plate (Welded Design) (EVT-1)Welded Shroud Plates (Full Height Design) (EVT-1)Core Shroud Assembly [Bolted (VT-3); Welded (VT-1)]Core Barrel Upper Flange Weld (EVT-1)Core Barrel Lower Cylinder Girth Welds (EVT-1)Core Support Column Welds (VT-3)Core Barrel Lower Flange (TLAA or EVT-1)Core Support Plate (TLAA or EVT-1)Fuel Alignment Plate (Full Height Design) (TLAA or EVT-1)Instrument Guide Tubes (in CEA Shroud Design) (VT-3)Lower Structure Beams (Full Height Design) (EVT-1) 8© 2015Electric Power Research Institute, Inc. All rights reserved.Westinghouse MR-227-A Primary ScopeControl Rod Guide Card wear inspections (VT-3)Lower Control Rod Guide Tube (CRGT) Lower Flange welds (EVT-1)Baffle Former Bolts (UT)Baffle Former Assembly (including seams) (VT-3)Baffle Former Edge Bolts (VT-3)Upper Core Barrel Flange to Shell Weld (EVT-1)Lower Core Barrel Flange Weld (EVT-1)Thermal Shield Flexures (VT-3)Core Barrel Cylinder Girth Welds (EVT-1)Internals Hold-Down Spring (if applicable material type)

(measurement) 9© 2015Electric Power Research Institute, Inc. All rights reserved.Examples of Inspected Components 10© 2015Electric Power Research Institute, Inc. All rights reserved.

WLower CRGT Flange Welds 11© 2015Electric Power Research Institute, Inc. All rights reserved.Thermal Shield Flexures (VT-3) 12© 2015Electric Power Research Institute, Inc. All rights reserved.

VT-3/Measurement WControl Rod Guide CardsAcceptableObserved Wear 13© 2015Electric Power Research Institute, Inc. All rights reserved.VT-3of B&W Control Rod Guide Tube (CRGT) Spacer Castings and Cap Screws 14© 2015Electric Power Research Institute, Inc. All rights reserved.Baffle-Former Assembly Bolts Internal Hex External Hex 15© 2015Electric Power Research Institute, Inc. All rights reserved.B&W Lower Barrel and Flow Distributor Bolts 16© 2015Electric Power Research Institute, Inc. All rights reserved.Core Barrel WeldsNeutron Panel and lower girth weld 17© 2015Electric Power Research Institute, Inc. All rights reserved.

Inspection Implementation 18© 2015Electric Power Research Institute, Inc. All rights reserved.

Inspection Implementation

-Some inspections best performed with core barrel in vessel

-Others require core barrel removal

-Common to split inspections over two or more outages

-Typically integrated with ASME Section XI exams

-Special tooling often required

-Vendor crew of roughly 20 specialists required 24/7

-Vendor crew typically experienced on both PWRs and BWRs-Owner oversight 19© 2015Electric Power Research Institute, Inc. All rights reserved.

Inspection Results 20© 2015Electric Power Research Institute, Inc. All rights reserved.Inspections by Plant Design -as of Fall 2014DesignInitial OpsBfl BltsCB BoltsCRGT SpcBMI SpdrBW19732012F2012F2012F2012FBW19732013S2013S2013S2013SBW19742014S2014S2014S2014S3 of 6 totalBfl BltsCRGT WldsCB WldsGd CardsLCSCE19712014S2014S2014S2014S1 of 12 totalBfl BltsCRGT WldsCB WldsGd CardsW219692011S2011S2011S2011SW219702013S2013S2013S2013SW219732014S2014S2014S W219742014F2014F W219742013F W319702013F2013F2012S W319722010F2012S2013F2012SW319722014S W319732011S2012S2014S2012SW319732014F 11 of 48 total 21© 2015Electric Power Research Institute, Inc. All rights reserved.

Results to DateInitial full inspections at W and B&W and partial CE NSSS designs have not identified any major issues of concernCurrent results reduce uncertainty in mechanism activityIssues of greatest concern not seen

-SCC of austenitic welded components not observedCracking currently limited to high strength bolting

-IASCC of welds not observed, indications limited to bolts

-Macroscopic effect of void swelling not observed 22© 2015Electric Power Research Institute, Inc. All rights reserved.By the Numbers

• 15units begun or co mpleted MRP inspections 959W guide tube flange welds inspected2427inches of irradiated welds inspected (approx.)9125inches of non-irradiated weldsinspected (approx.)2226CASS items inspected8887baffle bolts UT inspected**1654B&W high strength bolts UT inspected**108 B&W baffle plates inspected

• All numbers approximate. Includes r eported inspections through Fall 2014; some data includes retired plant; additional data may affect results slightly

• • Includes retired unit 23© 2015Electric Power Research Institute, Inc. All rights reserved.By the Numbers

• Zero Guide Tube Flange weld indicationsZero irradiated girth weld indicationsOne non-irradiated weld indicationOne CASS VT-3 indication136 baffle bolt indications (1.5% of total)20 B&W high strength bolt indications (1.2% of total)

• All numbers approximate. Includes reported inspections through Fall 2014 ; additional data may affect results slightly 24© 2015Electric Power Research Institute, Inc. All rights reserved.

Trends and ObservationsAlmost no observed austenitic SS stress corrosion cracking (one indication reported)Irradiation Assisted SCC is extremely limited

-Currently limited to bolts

-Explained in part by irradiation stress relaxation

-High barrier to initiation in PWR environment

-Compared to other plant designs, major benefit from coolant chemistry 25© 2015Electric Power Research Institute, Inc. All rights reserved.

Trends and ObservationsNo macroscopic effects of void swelling

-No distortions, cracking, or excessive bolting failureHigh-strength nickel alloy clevis insert bolting failures

-However, not in safety function load pathGuide card wear will require monitoring

-MRP Interim guidance MRP-2014-006 issued 26© 2015Electric Power Research Institute, Inc. All rights reserved.

Trends and ObservationsSampling approach to inspections very successful

-Spectrum of plant designs, materials, heats

-Transition to more focused sampling for guide cardsEfficiency could be increased, and is being pursuedIntegrated fleet management strategies are possible 27© 2015Electric Power Research Institute, Inc. All rights reserved.

MRP-227-A Experience SummaryExam results show few instances of service-induced degradation flaws, as expectedOverall uncertainty in aging mechanism activity reduced Implementation by owners is thorough, but exams are difficult, as well as resource and dose intensiveSome adjustments and efficiencies are needed, as expected with a 'living' programLessons learned incorporated into MRP-227 Rev. 1 28© 2015Electric Power Research Institute, Inc. All rights reserved.

Together-Shaping the Futur e of Electricity