ML18030A031: Difference between revisions

From kanterella
Jump to navigation Jump to search
(Created page by program invented by StriderTol)
(Created page by program invented by StriderTol)
 
(3 intermediate revisions by the same user not shown)
Line 3: Line 3:
| issue date = 02/10/1981
| issue date = 02/10/1981
| title = Final Deficiency Rept Re Ovality of Small Diameter Pipe at Bends Exceeding ASME Boiler & Pressure Vessel Code Tolerances,Initially Reported on 800411.Bends Will Be Dispositioned in Accordance W/Criteria by 810331
| title = Final Deficiency Rept Re Ovality of Small Diameter Pipe at Bends Exceeding ASME Boiler & Pressure Vessel Code Tolerances,Initially Reported on 800411.Bends Will Be Dispositioned in Accordance W/Criteria by 810331
| author name = CURTIS N W
| author name = Curtis N
| author affiliation = PENNSYLVANIA POWER & LIGHT CO.
| author affiliation = PENNSYLVANIA POWER & LIGHT CO.
| addressee name = GRIER B H
| addressee name = Grier B
| addressee affiliation = NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
| addressee affiliation = NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
| docket = 05000387, 05000388
| docket = 05000387, 05000388
Line 16: Line 16:


=Text=
=Text=
{{#Wiki_filter:00REGULATORY 1NFORlLiATION DISTRIBUTION SYSTEM(RIOS)ACCESSION NdR:8102180444 DUC~DATE:81/02/10NOTARIZED:
{{#Wiki_filter:0 REGULATORY 1NFORlLiATION DISTRIBUTION SYSTEM 0      (RIOS)
NOFACIL:50-87Susquehanna SteamElectricStation<UnitIRpennsylva sguehanna SteamEl.ectric Station<Unit2RPennsylva A,~AUTHURAFFILIATIONCUTISg>I~Ti~Pennsylvania PowertrIightCo.RECIP.~A~~E RECIPIc'NTAFFILIATION GRIERr8,h.ReasonIRPhilaaelphia<
ACCESSION NdR:8102180444                     DUC ~ DATE:               81/02/10      NOTARIZED:   NO              &#xb9; FACIL:50- 87 Susquehanna                  Steam    Electric Station< Unit                      IR pennsylva 05000387 sguehanna     Steam    El.ectric Station< Unit                    2R Pennsylva 05000388 A,I CU T S
OfficeoftheDirectorSUBJECT;Finaldeficiency reptreovalityofsmalldiameterpipeatbendsexceeoina AS4lEBoilerttPressureVesselCodetolerancesiin>tiatly reportedon800411.Benos willoedispositioned inaccordance w/criteriaby810331ROISTRISUTIOR COOE:SOISSOORIESRECEIVES:LTR 3ERCLfSIZE:TITLE:Construction OeficiencyReport(10CFR50~55E)NOTES:Send IH,E3copiesFSAR4allamends'enal 16E3copiesf-SAR4allamends'OCKET
        ~
&#xb9;05000387050003880500038705000388~ECIPIENTIDCODE/"lAt.1EACTION:A/9LICEHSI'tG OwRUSHBRODKztor
g >I ~ Ti ~
~nbINTERNAL:
AU THUR  AF F ILIATION Pennsylvania Power                    tr  I ight  Co.
AO/RCI/IEI?D/OIRHuqFAC15EOUttSTAFF19HYg/GEOBRLICQUALBRlgt~Rt:POR02EVI>nlST~NORDSOEV21COVIESLTl'RENCL111111111111IPECIPIENTIOCODE/NAME YOUNGBLOODEB 05STARKERS07ASLt3P/J.HARD DIRpOIVOFLICFAUIPilUALBR11IhE09SPA20OELO21QABR14RUTHERFORDRH, IECOPIESLrTRENCL1111111111111111111EXTERNAL:
RECIP.~A~~E                   REC IPIc'NT AFFILIATION GR IER r 8, h.                   Reason IR Philaaelphia<                       Office of the Director SUBJECT;       Final deficiency rept re ovality of small diameter pipe at amends'OCKET bends exceeoina AS4lE Boiler tt Pressure Vessel Code tolerancesiin>tiatly reported on 800411.Benos will oe dispositioned in accordance w/cr iteria by 810331R OISTRISUTIOR COOE: SOISS                  OORIES RECEIVES:LTR 3 ERCL TI TLE: Construction Oe f i c i ency Report (10CFR50 ~ 55E) f  SIZE:
ACRSr~SICloOola161LPOR03TOTAL'tu>lBEEr OFCOPIESrCEVUIRKO:
NOTES:Send           IH,E 3    copies  FSAR 4    all                                                      05000387 16E 3    copies  f-SAR 4    all  amends'enal 05000388
LTTR39FNCL39 lTWONORTHNINTHSTREET,ALLENTOWN, PA.18101PHONEr(215)7705151NORMANW.CURTISVicePresident-Engineering 3Construction-Nuclear 770.5381February10,1981Mr.BoyceH.Grier-Director, RegionIU.S.NuclearRegulatory Commission 631ParkAvenueKingofPrussia,PA19406SUSQUEHANNA STEAMELECTRICSTATIONFINALREPORTOFADEFICIENCY RELATINGTOOVALITYOFBENTPIPEERs100450/100508 FILE840-4/900-10 PLA-630
                    ~ECIP I ENT            COVIES                            PEC IP IENT          COPIES ID CODE/ "lAt.1E          LTl'R ENCL                      IO CODE/NAME          LrTR ENCL ACTION:         A/9 LICEHSI'tG       Ow        1      1                  YOUNGBLOODEB 05          1    1 RUSHBRODKztor ~       nb        1      1                  STARKERS          07      1    1 INTERNAL:       AO/RC      I/IE      I?               1                  ASLt3P/J.HARD DIR pOIV OF LIC 1    1 D/OIR Huq FAC15                        1                                              1    1 EOU      tt  STAFF    19                1                  FAUIP ilUAL BR11                1 HYg/GEO BR                              1                  IhE              09      1    1 LIC QUAL BR          lg                1                  SPA              20      1    1 t~Rt: POR            02                1                  OELO              21      1    1 EV  I>               1                  QA BR            14      1    1 nl                1                  RUTHERFORDRH,    IE      1    1 ST~NORDS        OEV 21                I EXTERNAL: ACRS                        lo      la    16                    LPOR              03 r~SIC                Oo                1 TOTAL 'tu>lBEEr OF COP IES rCEVUIRKO: LTTR                                39    FNCL    39
 
l TWO NORTH NINTH STREET, ALLENTOWN, PA. 18101        PHONEr (215) 770 5151 NORMAN W. CURTIS Vice President-Engineering 3 Construction-Nuclear 770.5381 February 10, 1981 Mr. Boyce H. Grier-Director, Region I U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406 SUSQUEHANNA STEAM ELECTRIC STATION FINAL REPORT OF A DEFICIENCY RELATING TO OVALITY OF BENT PIPE ERs    100450/100508               FILE 840-4/900-10 PLA-630


==Reference:==
==Reference:==
PLA-498 (6/20/80)
==Dear Mr. Grier:==
This    letter serves to provide the Commission with a final report of a deficiency relating to excessive ovality of small diameter pipe caused by bends which were produced in the field prior to the installation.
The ovality of the pipe at the bends exceeds the tolerances specified in the      ASME    Boiler        and Pressure  Vessel Code, Section    III, NB4223.2.
The    condition was originally reported in PLA-498, and the information contained herein is submitted as a final report pursuant to the provisions of 10 CFR 50.55(e).
The    attachment to this              letter contains a description of the problem; its cause,        safety implications and significance; and the corrective action taken and planned to preclude recurrence.
We    trust the Commission will find                the information forwarded by this letter to be satisfactory.
Very truly yours, Qorrt N. W.      Curtis                                                                        5 Vice President-Engineering                  & Construction-Nuclear FLW:sab                                                                                  I/i Attachment PENNSYLVANIA POWER      5 LIGHT COAIPANY al ezlaO
~ V ~
I
Mr. Boyce H. Grier                                  February 10, 1981 cc:  Mr. Victor Stello (15)
Director-Office of Inspection  a Enforcement U. S. Nuclear Regulatory Commission Washington, D.C. 20555 45 Office of  Management Information  & Program Control U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Mr. Robert M. Gallo U. S. Nuclear Regulatory Commission P.O. Box 52 Shickshinny, PA 18655
1
: 1. Description of Problem NCR-5523 dated        April 11,.1980, identified a nonconforming condition in. which small diameter pipe bent in'the field exceeds the tolerance stated in ASME, Section III, "NB-4223.2. Ovality Tolerance.
Unless otherwise justified by the Stress Report, the ovality of piping after bending shall not exceed 8 percent as determined by 100 K (D      - .D  .  )/D where.
D 0
The minimum      pipe outside diameter before bending or forming, in. (mm)
D      = The minimum outside diameter 'after bending or forming, in.
min  'mm)    .
D      = The maximum outside diameter after bending or forming, in.
max          1  I (mm)
Nuclear Class        II  and  III  piping are subject to the same provisions.
    . This formula is derived from the 1971 edition of Section                    III with
  . Addenda thru Winter, 1972. .This is the Code in effect for. this pro j e'ct.
Construction determined the values for D , D . , D                      through actual measurement of the pipe. D . anl D                      were 5etermined by taking 3 sets of readings inside tEe oend. Ponstruction used .the values from the point that produced the greatest variation. D was determined by a reading taken adjacent to the bend.
The  deficiency identified four stainless steel pipe bends where the ovality    exceeds    8g.
: 2.    'Cause  .of Deficiency The subject non-conforming condition has been primarily on pipe bends that were made in place, apparently using the Greenlee Model jj884 One Shot. hydraulic ram type bender; Sample bends made on this bender did not meet the 8$ ovality requirement.                    Bends made in the onsite pipe prefab          facility  on  the  Pedrick    mechanical  bender have been observed        to  be  better  than  those    made    on the  Greenlee  machine.
However,    even    these  bends  have  very  little    margin  with respect  to ovality.      Bends    made  in place  with  the    Ensley  mechanical  bender  d'o not appear to have ovality discrepancies.
Another contributing factor          is the lack of specific instructions to construction forces (via          specifications      for fabrication and installation of piping) for qualification          and  control      of pipe bending performed at the jobsite.
1of  3


PLA-498(6/20/80)
Siace there  is  no record of which bends were made on which machiae, all installed    bends are being checked for ovality. Only after a complete iaspection will the      full  magnitude of the problem be Mown. This inspectioa is being performed and documented as part of the'isposition of NCR-5523,. NCR-5674 aad additional NCR's.
'
: 3. Analysis of Safety Impli'cation Project Engiaeeriag has developed acceptaace criteria based on stress analysis for pipe bends with.ovality up'to 15$ . Maximum ovality permitted is 8$ for pipiag which is subject to temperature traasients and 15$ for piping which is not subject.to temperature transients. Additionally the bends must be free of rapid chaages in curvature aad circumferential kinks or concavity as defined in the criteria. Wall thickaess, after bending, must meet desiga
  . minimum; The effect on flow (pressure drop) due to reduced cross
  ~
sectional area of bends with up to 15$ ovality was addressed and .
found to be insignificaat.
Approximately 700 bends, including all bends in small piping within the primary reactor pressure vessel bouadary have been iaspected aad dispositioaed ia accordance with the criteria; Although the balance of bends (approximately 5,000), in safety related systems have not been inspected    it  is felt that the work to date i's a represeatative sample and is adequate to evaluate the safety impli-cations.
Of the approximately 700 bends checked as of Dec. 1980, one exceeded 15X ovality and two exceeded the 8$ ovality limit for piping subject. to temperature transients. These three bends have been replaced.
Approximately 240 bends measured fell between the 8-15$ limit allowed for systems not subject to temperature transients.
Three  installed bends in safety related piping had to be replaced to'meet the project engineering acceptance criteria. Aay bends which d'o not meet the acceptaace criteria are ass~ed to fail in service. Such failures could'ave affected adversely the safety of operatioas of 'the plant. Therefore, this coaditioa is -considered reportable under 10 CZR 50.55(e)'.
: 5. Corrective Action The acceptance    criteria was  issued on May 30, 1980. Coastructioa anticipates completiag approximately 1250 bends per month        and  that final corrective action will be completed, for Unit 1 aad        Common, by March, 1981.              ~      ~              ~
Specificatioa    M-204 for fabrication and, installation of pi>fag has been amended  to require field procedures to control and monitor future bending to ensure that 8$ ovality is not exceeded and that beads exceeding this limit or any other criteria shall be rejected.
2qf  3


==DearMr.Grier:==
Corrective Action'to Preclude Recurrence 6.
ThisletterservestoprovidetheCommission withafinalreportofadeficiency relatingtoexcessive ovalityofsmalldiameterpipecausedbybendswhichwereproducedinthefieldpriortotheinstallation.
    -E~bdb'd'p''d'd*'PP Engineering- acceptance criteria. All measurements are being verified by on site quality control personnel. For future bends, a program has been instituted to'ave all bends checked for ovality by the responsible system engineers prior to installation of the bend.
Theovalityofthepipeatthebendsexceedsthetolerances specified intheASMEBoilerandPressureVesselCode,SectionIII,NB4223.2.
Also, all applicable superintendents have been directed to insure that proper bending equipment, and techniques are used for all. pipe .
Thecondition wasoriginally reportedinPLA-498,andtheinformation contained hereinissubmitted asafinalreportpursuanttotheprovisions of10CFR50.55(e).
behds. In addition, Quality Control has been requested to inspect and document  all  Q-bends for ovality.
Theattachment tothislettercontainsadescription oftheproblem;itscause,safetyimplications andsignificance; andthecorrective actiontakenandplannedtoprecluderecurrence.
Use of the Greenlee "one shot" bender has been discontinued for bending pipe. Also, a Pedrick representative visited the jobsite and.provided instruction as to the proper use and maintenance of the Pedrick bending machine, and re'commended some replacement parts where the shoes were worn. Those. parts have been replaced.
WetrusttheCommission willfindtheinformation forwarded bythislettertobesatisfactory.
2U/AAW 3of  3}}
Verytrulyyours,N.W.CurtisVicePresident-Engineering
&Construction-Nuclear FLW:sabQorrt5I/iAttachment alezlaOPENNSYLVANIA POWER5LIGHTCOAIPANY
~V~I Mr.BoyceH.GrierFebruary10,1981cc:Mr.VictorStello(15)Director-Office ofInspection aEnforcement U.S.NuclearRegulatory Commission Washington, D.C.2055545OfficeofManagement Information
&ProgramControlU.S.NuclearRegulatory Commission Washington, D.C.20555Mr.RobertM.GalloU.S.NuclearRegulatory Commission P.O.Box52Shickshinny, PA18655 11.Description ofProblemNCR-5523datedApril11,.1980, identified anonconforming condition in.whichsmalldiameterpipebentin'thefieldexceedsthetolerance statedinASME,SectionIII,"NB-4223.2.
OvalityTolerance.
Unlessotherwise justified bytheStressReport,theovalityofpipingafterbendingshallnotexceed8percentasdetermined by100K(D-.D.)/Dwhere.D0DminDmaxTheminimumpipeoutsidediameterbeforebendingorforming,in.(mm)=Theminimumoutsidediameter'afterbendingorforming,in.'mm).=Themaximumoutsidediameterafterbendingorforming,in.(mm)1INuclearClassIIandIIIpipingaresubjecttothesameprovisions.
.Thisformulaisderivedfromthe1971editionofSectionIIIwith.AddendathruWinter,1972..ThisistheCodeineffectfor.thisproje'ct.Construction determined thevaluesforD,D.,Dthroughactualmeasurement ofthepipe.D.anlDwere5etermined bytaking3setsofreadingsinsidetEeoend.Ponstruction used.thevaluesfromthepointthatproducedthegreatestvariation.
Dwasdetermined byareadingtakenadjacenttothebend.Thedeficiency identified fourstainless steelpipebendswheretheovalityexceeds8g.2.'Cause.ofDeficiency Thesubjectnon-conforming condition hasbeenprimarily onpipebendsthatweremadeinplace,apparently usingtheGreenleeModeljj884OneShot.hydraulic ramtypebender;Samplebendsmadeonthisbenderdidnotmeetthe8$ovalityrequirement.
BendsmadeintheonsitepipeprefabfacilityonthePedrickmechanical benderhavebeenobservedtobebetterthanthosemadeontheGreenleemachine.However,eventhesebendshaveverylittlemarginwithrespecttoovality.BendsmadeinplacewiththeEnsleymechanical benderd'onotappeartohaveovalitydiscrepancies.
Anothercontributing factoristhelackofspecificinstructions toconstruction forces(viaspecifications forfabrication andinstallation ofpiping)forqualification andcontrolofpipebendingperformed atthejobsite.1of3 Siacethereisnorecordofwhichbendsweremadeonwhichmachiae,allinstalled bendsarebeingcheckedforovality.Onlyafteracompleteiaspection willthefullmagnitude oftheproblembeMown.Thisinspectioa isbeingperformed anddocumented aspartofthe'isposition ofNCR-5523,.
NCR-5674aadadditional NCR's.3.AnalysisofSafetyImpli'cation ProjectEngiaeeriag hasdeveloped acceptaace criteriabasedonstressanalysisforpipebendswith.ovality up'to15$.Maximumovalitypermitted is8$forpipiagwhichissubjecttotemperature traasients and15$forpipingwhichisnotsubject.to temperature transients.
Additionally thebendsmustbefreeofrapidchaagesincurvature aadcircumferential kinksorconcavity asdefinedinthecriteria.
Wallthickaess, afterbending,mustmeetdesiga.minimum;Theeffectonflow(pressure drop)duetoreducedcross~sectional areaofbendswithupto15$ovalitywasaddressed and.foundtobeinsignificaat.
Approximately 700bends,including allbendsinsmallpipingwithintheprimaryreactorpressurevesselbouadaryhavebeeniaspected aaddispositioaed iaaccordance withthecriteria; Althoughthebalanceofbends(approximately 5,000),insafetyrelatedsystemshavenotbeeninspected itisfeltthattheworktodatei'sarepreseatative sampleandisadequatetoevaluatethesafetyimpli-cations.Oftheapproximately 700bendscheckedasofDec.1980,oneexceeded15Xovalityandtwoexceededthe8$ovalitylimitforpipingsubject.totemperature transients.
Thesethreebendshavebeenreplaced.
Approximately 240bendsmeasuredfellbetweenthe8-15$limitallowedforsystemsnotsubjecttotemperature transients.
Threeinstalled bendsinsafetyrelatedpipinghadtobereplacedto'meettheprojectengineering acceptance criteria.
Aaybendswhichd'onotmeettheacceptaace criteriaareass~edtofailinservice.Suchfailurescould'ave affectedadversely thesafetyofoperatioas of'theplant.Therefore, thiscoaditioa is-considered reportable under10CZR50.55(e)'.
5.Corrective ActionTheacceptance criteriawasissuedonMay30,1980.Coastructioa anticipates completiag approximately 1250bendspermonthandthatfinalcorrective actionwillbecompleted, forUnit1aadCommon,byMarch,1981.~~~Specificatioa M-204forfabrication and,installation ofpi>faghasbeenamendedtorequirefieldprocedures tocontrolandmonitorfuturebendingtoensurethat8$.ovalityisnotexceededandthatbeadsexceeding thislimitoranyothercriteriashallberejected.
2qf3 6.Corrective Action'to PrecludeRecurrence
-E~bdb'd'p''d'd*'PP Engineering-acceptance criteria.
Allmeasurements arebeingverifiedbyonsitequalitycontrolpersonnel.
Forfuturebends,aprogramhasbeeninstituted to'aveallbendscheckedforovalitybytheresponsible systemengineers priortoinstallation ofthebend.Also,allapplicable superintendents havebeendirectedtoinsurethatproperbendingequipment, andtechniques areusedforall.pipe.behds.Inaddition, QualityControlhasbeenrequested toinspectanddocumentallQ-bendsforovality.UseoftheGreenlee"oneshot"benderhasbeendiscontinued forbendingpipe.Also,aPedrickrepresentative visitedthejobsiteand.provided instruction astotheproperuseandmaintenance ofthePedrickbendingmachine,andre'commended somereplacement partswheretheshoeswereworn.Those.partshavebeenreplaced.
2U/AAW3of3}}

Latest revision as of 16:28, 3 February 2020

Final Deficiency Rept Re Ovality of Small Diameter Pipe at Bends Exceeding ASME Boiler & Pressure Vessel Code Tolerances,Initially Reported on 800411.Bends Will Be Dispositioned in Accordance W/Criteria by 810331
ML18030A031
Person / Time
Site: Susquehanna  Talen Energy icon.png
Issue date: 02/10/1981
From: Curtis N
PENNSYLVANIA POWER & LIGHT CO.
To: Grier B
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
10CFR-050.55E, 10CFR-50.55E, ER-100450, ER-100508, PLA-630, NUDOCS 8102180444
Download: ML18030A031 (7)


Text

0 REGULATORY 1NFORlLiATION DISTRIBUTION SYSTEM 0 (RIOS)

ACCESSION NdR:8102180444 DUC ~ DATE: 81/02/10 NOTARIZED: NO ¹ FACIL:50- 87 Susquehanna Steam Electric Station< Unit IR pennsylva 05000387 sguehanna Steam El.ectric Station< Unit 2R Pennsylva 05000388 A,I CU T S

~

g >I ~ Ti ~

AU THUR AF F ILIATION Pennsylvania Power tr I ight Co.

RECIP.~A~~E REC IPIc'NT AFFILIATION GR IER r 8, h. Reason IR Philaaelphia< Office of the Director SUBJECT; Final deficiency rept re ovality of small diameter pipe at amends'OCKET bends exceeoina AS4lE Boiler tt Pressure Vessel Code tolerancesiin>tiatly reported on 800411.Benos will oe dispositioned in accordance w/cr iteria by 810331R OISTRISUTIOR COOE: SOISS OORIES RECEIVES:LTR 3 ERCL TI TLE: Construction Oe f i c i ency Report (10CFR50 ~ 55E) f SIZE:

NOTES:Send IH,E 3 copies FSAR 4 all 05000387 16E 3 copies f-SAR 4 all amends'enal 05000388

~ECIP I ENT COVIES PEC IP IENT COPIES ID CODE/ "lAt.1E LTl'R ENCL IO CODE/NAME LrTR ENCL ACTION: A/9 LICEHSI'tG Ow 1 1 YOUNGBLOODEB 05 1 1 RUSHBRODKztor ~ nb 1 1 STARKERS 07 1 1 INTERNAL: AO/RC I/IE I? 1 ASLt3P/J.HARD DIR pOIV OF LIC 1 1 D/OIR Huq FAC15 1 1 1 EOU tt STAFF 19 1 FAUIP ilUAL BR11 1 HYg/GEO BR 1 IhE 09 1 1 LIC QUAL BR lg 1 SPA 20 1 1 t~Rt: POR 02 1 OELO 21 1 1 EV I> 1 QA BR 14 1 1 nl 1 RUTHERFORDRH, IE 1 1 ST~NORDS OEV 21 I EXTERNAL: ACRS lo la 16 LPOR 03 r~SIC Oo 1 TOTAL 'tu>lBEEr OF COP IES rCEVUIRKO: LTTR 39 FNCL 39

l TWO NORTH NINTH STREET, ALLENTOWN, PA. 18101 PHONEr (215) 770 5151 NORMAN W. CURTIS Vice President-Engineering 3 Construction-Nuclear 770.5381 February 10, 1981 Mr. Boyce H. Grier-Director, Region I U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406 SUSQUEHANNA STEAM ELECTRIC STATION FINAL REPORT OF A DEFICIENCY RELATING TO OVALITY OF BENT PIPE ERs 100450/100508 FILE 840-4/900-10 PLA-630

Reference:

PLA-498 (6/20/80)

Dear Mr. Grier:

This letter serves to provide the Commission with a final report of a deficiency relating to excessive ovality of small diameter pipe caused by bends which were produced in the field prior to the installation.

The ovality of the pipe at the bends exceeds the tolerances specified in the ASME Boiler and Pressure Vessel Code, Section III, NB4223.2.

The condition was originally reported in PLA-498, and the information contained herein is submitted as a final report pursuant to the provisions of 10 CFR 50.55(e).

The attachment to this letter contains a description of the problem; its cause, safety implications and significance; and the corrective action taken and planned to preclude recurrence.

We trust the Commission will find the information forwarded by this letter to be satisfactory.

Very truly yours, Qorrt N. W. Curtis 5 Vice President-Engineering & Construction-Nuclear FLW:sab I/i Attachment PENNSYLVANIA POWER 5 LIGHT COAIPANY al ezlaO

~ V ~

I

Mr. Boyce H. Grier February 10, 1981 cc: Mr. Victor Stello (15)

Director-Office of Inspection a Enforcement U. S. Nuclear Regulatory Commission Washington, D.C. 20555 45 Office of Management Information & Program Control U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Mr. Robert M. Gallo U. S. Nuclear Regulatory Commission P.O. Box 52 Shickshinny, PA 18655

1

1. Description of Problem NCR-5523 dated April 11,.1980, identified a nonconforming condition in. which small diameter pipe bent in'the field exceeds the tolerance stated in ASME,Section III, "NB-4223.2. Ovality Tolerance.

Unless otherwise justified by the Stress Report, the ovality of piping after bending shall not exceed 8 percent as determined by 100 K (D - .D . )/D where.

D 0

The minimum pipe outside diameter before bending or forming, in. (mm)

D = The minimum outside diameter 'after bending or forming, in.

min 'mm) .

D = The maximum outside diameter after bending or forming, in.

max 1 I (mm)

Nuclear Class II and III piping are subject to the same provisions.

. This formula is derived from the 1971 edition of Section III with

. Addenda thru Winter, 1972. .This is the Code in effect for. this pro j e'ct.

Construction determined the values for D , D . , D through actual measurement of the pipe. D . anl D were 5etermined by taking 3 sets of readings inside tEe oend. Ponstruction used .the values from the point that produced the greatest variation. D was determined by a reading taken adjacent to the bend.

The deficiency identified four stainless steel pipe bends where the ovality exceeds 8g.

2. 'Cause .of Deficiency The subject non-conforming condition has been primarily on pipe bends that were made in place, apparently using the Greenlee Model jj884 One Shot. hydraulic ram type bender; Sample bends made on this bender did not meet the 8$ ovality requirement. Bends made in the onsite pipe prefab facility on the Pedrick mechanical bender have been observed to be better than those made on the Greenlee machine.

However, even these bends have very little margin with respect to ovality. Bends made in place with the Ensley mechanical bender d'o not appear to have ovality discrepancies.

Another contributing factor is the lack of specific instructions to construction forces (via specifications for fabrication and installation of piping) for qualification and control of pipe bending performed at the jobsite.

1of 3

Siace there is no record of which bends were made on which machiae, all installed bends are being checked for ovality. Only after a complete iaspection will the full magnitude of the problem be Mown. This inspectioa is being performed and documented as part of the'isposition of NCR-5523,. NCR-5674 aad additional NCR's.

3. Analysis of Safety Impli'cation Project Engiaeeriag has developed acceptaace criteria based on stress analysis for pipe bends with.ovality up'to 15$ . Maximum ovality permitted is 8$ for pipiag which is subject to temperature traasients and 15$ for piping which is not subject.to temperature transients. Additionally the bends must be free of rapid chaages in curvature aad circumferential kinks or concavity as defined in the criteria. Wall thickaess, after bending, must meet desiga

. minimum; The effect on flow (pressure drop) due to reduced cross

~

sectional area of bends with up to 15$ ovality was addressed and .

found to be insignificaat.

Approximately 700 bends, including all bends in small piping within the primary reactor pressure vessel bouadary have been iaspected aad dispositioaed ia accordance with the criteria; Although the balance of bends (approximately 5,000), in safety related systems have not been inspected it is felt that the work to date i's a represeatative sample and is adequate to evaluate the safety impli-cations.

Of the approximately 700 bends checked as of Dec. 1980, one exceeded 15X ovality and two exceeded the 8$ ovality limit for piping subject. to temperature transients. These three bends have been replaced.

Approximately 240 bends measured fell between the 8-15$ limit allowed for systems not subject to temperature transients.

Three installed bends in safety related piping had to be replaced to'meet the project engineering acceptance criteria. Aay bends which d'o not meet the acceptaace criteria are ass~ed to fail in service. Such failures could'ave affected adversely the safety of operatioas of 'the plant. Therefore, this coaditioa is -considered reportable under 10 CZR 50.55(e)'.

5. Corrective Action The acceptance criteria was issued on May 30, 1980. Coastructioa anticipates completiag approximately 1250 bends per month and that final corrective action will be completed, for Unit 1 aad Common, by March, 1981. ~ ~ ~

Specificatioa M-204 for fabrication and, installation of pi>fag has been amended to require field procedures to control and monitor future bending to ensure that 8$ ovality is not exceeded and that beads exceeding this limit or any other criteria shall be rejected.

2qf 3

Corrective Action'to Preclude Recurrence 6.

-E~bdb'd'pd'd*'PP Engineering- acceptance criteria. All measurements are being verified by on site quality control personnel. For future bends, a program has been instituted to'ave all bends checked for ovality by the responsible system engineers prior to installation of the bend.

Also, all applicable superintendents have been directed to insure that proper bending equipment, and techniques are used for all. pipe .

behds. In addition, Quality Control has been requested to inspect and document all Q-bends for ovality.

Use of the Greenlee "one shot" bender has been discontinued for bending pipe. Also, a Pedrick representative visited the jobsite and.provided instruction as to the proper use and maintenance of the Pedrick bending machine, and re'commended some replacement parts where the shoes were worn. Those. parts have been replaced.

2U/AAW 3of 3