ML23079A263
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| ML23079A263 | |
| Person / Time | |
|---|---|
| Issue date: | 03/23/2023 |
| From: | Siva Lingam Licensing Processes Branch |
| To: | |
| References | |
| Download: ML23079A263 (1) | |
Text
VisualExaminationof ContainmentSurfacesCoveredby Insulation March 23, 2023 Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission
MeetingAgenda
- Introduction/OpeningRemarks NRC/NEI
- NRCPresentation NRC
- NEI/IndustryPresentation NEI/Industry
- Brainstorming/GeneralDiscussion/Questions All
- Closing NRC 2
March23,2023
=
Background===
- PreviousPublicMeeting(1/19/23;ML23024A262)
- Alignmentnotreachedoninterpretationofexistingcoderequirements
- Significantdiscussionaboutpermanentvsremovable
- Generalagreementthatcurrentwordingcouldbeclarified
- Actions:
- NEIagreedtoprovideexamplesofinaccessibleevaluations
- NRCagreedtoscheduleafollowupmeeting
- TopicalsodiscussedduringASMEContainmentworkinggroup meeting,ASMENRCmanagementcall,PWROGExecutive ManagementMeeting,andNEINRCmanagementmeetings 3
March23,2023
StaffActionsSincePreviousMeeting
- ReviewedexamplesprovidedbyNEI:
- Examplesoftwolicenseesproperlyexpandingthescopeto inaccessibleareaswhendegradationisidentifiedinaccessibleareas
- Staffconcernedthisrequirementmaynotaddresstheareas currentlybeingdiscussed
- Ifthepenetrationsinquestionareclassifiedasinaccessibleunder theinspectionplan,ISIinspectorswillnotinspectthepenetration
- Needstobearequirementtoinspectthegeneralareaaroundthe penetration 4
March23,2023
StaffActionsSincePreviousMeeting
- Reviewofpastreliefrequestsandgenericcommunications
- Additionaldiscussionswithinspectorsandlicensees:
- Somelicenseesplanningtoremoveinsulationfromreadilyaccessible penetrationsduringupcomingoutages
- Somelicenseeshaveandareremovingthisinsulationtoconduct theIWEgeneralvisualexams,orhavesoughtrelieffornot removingtheinsulation
- CurrentStaffPosition:Theseareasneedtobeinspectedonsome frequencyduringthelifeoftheplant 5
March23,2023
StaffActionsSincePreviousMeeting
- StaffacknowledgesNRCpositionneedsadditionalreview
- NRRissuedmemotoregionsonMarch10,2023,providing guidanceonanyidentifiedissuesduringongoinggeneric evaluationofissue(ML23046A398):
- UseVLSSIRiflowsafetysignificanceandplantspecificlicensingbasisnotclear
- CoordinatewithNRRforothersituations
- Focustodayshouldbeondiscussingwhatlevelofinspectionis necessaryforsafety:
- Thestaffdoesnotbelievetheseareasshouldneverbeinspected; andinspectioneveryperiodislikelyunnecessaryforsafety 6
March23,2023
PathForward:SafetyFocusedSolution Engagestakeholdersduringthe50.55arulemakingprocessandinASME Codeengagementtodevelopasolutionthatbalancessafetyandrisk
- Wheredoweneedtoinspect?
- Focusedonlikelihoodofdegradationoreaseofaccess?
- Samplingbasisor100%overangiventimeframe?
- Definewhatisconsideredreadilyaccessible?
- Ifpenetrationsareidentifiedasinaccessiblehowdoinspectorsknowtoinspect thesurroundingareas?
- Howoftendoweneedtoinspect?
- Onceaninterval?
- Canweinformtheintervalbasedoncorrosionrates?
7 March23,2023
OperatingExperience
- Staffreviewedpastcontainmentlinerdegradation.
- OperatingExperienceindicatesthatdegradationcaninitiateon theinneroroutersurfacesofthecontainmentliner.
- Almostalldegradationexampleswerediscoveredduetoroutine IWEGeneralVisualExamination.
- Outsidesurfacedegradationistypicallynotdiscovereduntil perforationoftheliner.
- Insidesurfacedegradationhasrangedfromsurfacecorrosionto about50%throughwallwhenfirstidentified.
8 March23,2023
OperatingExperience
- Outersurfacedegradationistypicallycausedbyunexpectedforeign objectsembeddedintheconcrete(wood,gloves,tools,etc).
- ForInnersurfacedegradation,InformationNotice1997010specifically identifiesfiveareasofincreasedlikelihoodforlinerplatecorrosion:
- 1. Junctionofcontainmentcylinderandintermediatefloorsorbasemat concrete.
- 2. Junctionofdrywellandthebaseorintermediateconcretefloors.
- 3. Adjacenttocranegirderrailsandsupportsattachedtothelinerplate.
- 4. Watersoakedareaswherecarbonsteellinerplateisused.
- 5. Behindinsulationandicecondenserbasketsduetolikelihoodformoistureto condense.
9 March23,2023
PathForward:SafetyFocusedSolution BrainstormingSessionafterNEI/Industrypresentation
- Wheretoinspect?
- Whentoinspect?
- GeneralDiscussion/Questions 10 March23,2023
Brainstorm:Wheretoinspect?
11 March23,2023
Brainstorm:Whentoinspect?
12 March23,2023
GeneralDiscussion/Questions 13 March23,2023
BackupSlides 14 March23,2023
IWEWording
- IWE1232(c):SurfaceareasofClassMCcontainmentvessels,partsand appurtenances,andsurfaceareasofClassCCmetallicshellandpenetrationliners areconsideredinaccessibleifvisualaccessbylineofsightfrompermanent vantagepointsisobstructedbypermanentplantstructures,equipment,or components,providedthesesurfaceareasdonotrequireexaminationin accordancewiththeinspectionplanorIWE1240.
- IWE2310(d):(d)Visualexaminationsshallbeperformed,eitherdirectlyor remotely,bylineofsightfromfloors,platforms,walkways,ladders,orother permanentvantagepoints,unlesstemporaryaccessisrequiredbytheinspection plan.
15 March23,2023
InterpretationXI11325
- Q1:IsitarequirementofIWE1230thatcontainmentsurfacecoveredby thermalinsulationbeconsideredaccessibleforgeneralvisualexaminationin accordancewithTableIWE25001,ExaminationCategoryEA?
- Reply(1):No.
- Q2:IsitarequirementofIWE1230thatcontainmentsurfacecoveredby thermalinsulationbeconsideredaccessibleforaugmentedexaminationin accordancewithTableIWE25001,ExaminationCategoryEC,ifthese surfacesaresubjecttoaccelerateddegradationandaging?
- Reply(2):Yes.
- ASMERecordNumber:132137;Issued3/7/2014
- Theoriginalinterpretationquestionnotedthatinmanycases,[the]
insulationmaterialisnotintendedtoberemovedandisphysicallyattachedto thecontainmentsurface.
16 March23,2023
ApprovedCodeChange 17 March23,2023
NRCComment
- During the initial discussion of this item, proposed (d) included wording that required an evaluation of inaccessible areas to demonstrate they are not experiencing accelerated degradation or exposed to conditions described in IWE-1240. Ultimately, the working group determined this wording was unnecessary for this action and focused the proposed changes on incorporating the existing ASME position on the accessibility of surfaces covered by insulation, as captured in Interpretation XI-1-13-25. The NRC believes the proposed edits capture the ASME position on accessible surfaces as documented in Interpretation XI-1 25, which is why the staff is voting yes. However, the staff believes the code is unclear how IWE-1241 is implemented to identify surfaces requiring augmented examination in accordance with Table IWE-2500-1. Therefore, the staff may consider a future condition related to inaccessible surfaces and paragraphs IWE-1232 or IWE-1240.
18 March23,2023