ML20202C471
| ML20202C471 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 01/30/1998 |
| From: | PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9802120256 | |
| Download: ML20202C471 (48) | |
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-A 10CFR$0.55a
=sjipr PECO NUCLEAR nco % c-A Unit of PECO Energy NrYN.N January 30,1998 Docket No. 50-352 50 353 License No. NPF 39 NPF 85 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555
Subject:
Limerick Generating Station, Units 1 and 2 Submittal of Relief Requests Conceming Reactor Pressure Vessels and ASME Section XI Code Cases
Dear Sir:
By letter dated April 27,1995, as supplemented by letter dated September 25,1995, PECO Energy submitted a request proposing an attemative to updating the Limerick Generating Station (LGS), Unit 1, inservice Inspection (ISI), inservice Testing (IST), and Repair and Replacement
. Pro 0 rams to the latest edhion of the American Society of Mechanical Engineers (ASME) Boller and Pressure Vessel (B&PV) Code following the completion of the First inspection interval as required by 10CFR50.55a(g)(4)(ll). Specifically, we proposed to begin the Second Inspection Interval for LGS, Unit 1 and Common, as normally scheduled, using the existing Code requirements (i.e., First inspection Interval requirements), as described in Section XI of the 1986 Edition of the Code with plans to update both the Unit i and Unit 2 Programs simultaneously to the same Edition and Addenda of the Section XI Code t5.at will be in effect 12 months prior to the start of the LGS, Unit 2. Second Inspection Interval. The NRC s:aff authorized ol'r proposed attemative, pursuant to 10 CFR 50.55a(a)(3)(li), by letter and SEP dated January 23,1996.
All ISI Prograin Ret.ef Requests, approved for use during the LGS Unit 1 First inspection Interval wore resubmitted with our September 25,1995 correspondence for approval for use during the Neond Inspection Interval. All C, ode Cases which had been used during the LGS Unit 1 First inspection Interval were also resubmitted with our September 25,1995 corresponcence based on their planned use during the Second Inspection Interval.
The LGS, Unit 1, First inspection interval ISI Program began on February 1,1986. The scheduled end date was extended one (1) year to February 1,1997, in accordance with ASME Sec'.lon XI Code, lWA 2430(d).This change was necessary in order to facilitate the preparation and implementation of ASME Code pressure tests (i.e.,Section XI, Subsection IWA 5000) that are now required as a result of the NRC's approvs' of ISI Program Relief Request No. RR 13, Revision 2, for the LGS, Unit 1, as documented in an NRC letter dated Octooer 5,1995. The LGS, Unit 2;First inspection Interval ISI Program began on January 8,1990. The LGS Unit 2
.Sirst inspection Interval is currently scheduled to end on January 8,2000. The change to the LGS, Unit 1. First inspection Interval scheduled end date also afforded PECO t.
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January 30,1998 Page 2 Energy the opportinity 4. anplete the LOS, Unit 2. First inspection interval examinations of the reactor pressure vessel (RPV) utilizing existing ASME Section XI First inspection interval 181 Program requirements to satisfy the requiremerW for augmented examination of the RPV pursuant to 10CFR50.55a(g)($)(ii)(A)(4), as was done for LG8, Unit 1.
At this time, all LGS, UnN 1, FirW Inspection Interval requirements have been completed. PECO Energy has performed a review of the ASME Section XI Code Bases desertbed in the LOS, Unit
- 1. First (and Second) mapection interval 181 Program to deturmine if NRC approval of requests for relief from certain Code requirements have been secured or the need for addnional relief has
- been identified. APhough one (1) refueling outage still remains for the completion of the LGS, Unit 2 First inspect 6on Interval requirements, PECO Energy has included LOS, UnN 2. In this correspondence in order to facilNete consistency and commonality in the LGS, Units 1 and 2, ASME Section XI Programs. provides a summary of the LG8, Units 1 and 2 First (and Second) Inservios
-- Inspection interval 181 Program requests for relief from certain ASME Code requirements. The
- relief request identification number, Code requirement applicability and NRC approval status are included in the tabulationi provides a list of the ASME Code Cases either currently in or planned for incktsion in the Code Bases for the LG8, Units 1 and 2 First (and Second) inservios inspectan Interval 181 Programs. to this correspondence is the result of PECO Energy's review of the current ASME Section XI Code Bases described in the LGS, Units 1 and 2, First (and Second) Inspection interval 181 Programs. It identifies those Code requirements for w5ich additional relief is required
' and is submitted herein for NRC approval of PECO Energy's proposed altamatives pursuant to 10CFR50.55a(3). All items in Attachment 3 have been reviewed previously by the NRC; however, Relief Request Nos. RR 01, RR 05 and RR 11 have been completely rewritten and should be reviewed in their entirety. The changes from the previously reviewed versions of Relief Request Nos. RR 12 and RR 23 are identified by revision bars on the right hand side of the text.
This relief is being pursued by the ervt of the eleventh year following the end of the LG8, Unit 1 First inspection Interval, as required by 10CFR50.55a'.3)(5)(iv) srid in accordance with 10CFR50.55a(g)(5)(lii) for LGS Unit 2.
If you have any questions or require additional information, please do not hesitate to contact us.
Very truly youm,-
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Director Licensing -
Limerick Generating Station, Units 1 and 2, Inservios inspection ISI Program Relief Requests Summary Limonck Generating Station, Units 1 and 2,
= Code Cases Applicable to the ISI and Repair and Replacement Programs. J Limerick Generating Stat'on, Units 1 and 2 4
Revised Relief Requests RR 01, RR 05, RR 11, RR 12 and RR 23 cc: H. J. Miller, Administrator, USNRC, Region 1 (w/ attachments)._
~ A' L. Burritt, USNRC Senior Resident inspector, LGS (w/ attachments)
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V ATTACHMENT 11 Limerick Ger.erating Station, Units 1 and 2,
inservios inspection 181 Program Relief Requests Summary
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Page 1 of 8 ATTACHMENT 1 Limenck Generating Station. Units 1 and 2, inservce i.iA7 ISI Program Relieflisquests Summary RELIEF REQOtiST EXAMINATION CATEGORY ITEM No.
APPROVAL STATUS NO.
Unit 1 Unit 2 RR-01 B-A Pressure retaining welds in B122 Head welds (Mendiornal)
Re/ision 1 approved Revi@ 0 avviaved reacto vessel with wn..=G per per Reference 1:
Reference 2-includes ! tem Nos.
Item No. B1.10 B1.10 and 8120 welds denied.
Item No. 81.10 weids removed from RR-01 Resison 0 by PECO Energy per 10CFR50 Rule Malung dated 9/ES2.
RR-02 B-L-2 Purnp casings (intemal B1220 Pump casing Revison 0 Revison 0 appOved Surfaces) reJ umd without with comment per wii.roit per Reference 1.
Reference 2.
RR-03 B-M-2 Valve bodies (intemal B12.50 Va!ve body, exceeoing NPS 4 Revison 0 Revtson 0 appcyed Surfaces) sen..rmd without with comment per uni c.ent per Reference 1 Reisee.e 2.
document valve groups not dhriAed in End-of-tr.terval Summary Report.
RR-04 F-C Component stancard F3.50 Spring type supports, con: tant Revison 1 appivved Revison 0 aprOved supports load type suppeds, shock per Refererce 2.
per Reference i; absorbers,hydraui~ and document pumps not o
l mechanical type snubbers.
hidded in l
End-of-interval Summary Report.
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' ATTACHENT1:
4L bmenck Generahng Stemon. Units 1 and 2. '
Insonnoe inspeckon ISE Program Relief famy* Summary g.
RR-05 C-C-integral matartiments for c-C3.10 Integragywelded attacisnonts asineson 0 Rs.ioion 0 approved vessels,ppng, pumps,and (Pressure VM) '
respirmed por -
por Reference 1...
valves Reference 2.
C3.20 :
Integra5ywelded altechments (Peng)
C3.30L Irwegreeyweided selschments (Pumps)
RR-06 C.A Pressure rotorung welds in i C1.10 '
Shes circumferenkelwelds Revieson 0 Revieson 0 approved pressure vessels resNirmed per per Reference 1.
Reference 2.
RR C-G Pressure reta. r.;, welds in C6.10.
Pump caseng welds Revision O.
Rowieson 0 approved 1-pumps and valves reeHirmed per -
witicomment por i
Refuence 2.
Reference 1: '
document volve Groups not Nin End-of-interval Summary Report RR-06 B-D Fuu penetrabon welds of B3_90 Nozzle to vesselweeds Revieson 0 Revieson 0 approved nozzles in vessels (inspechon (RoectorVessel).
resNirmed per per Refererce 1.
t Program e)
Reference 2.
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inservice inspecnon ISE Pmgram Rsiiof Rage Sunmry RR F-A Plate and sheE type supports F1.10 Moctionscalconnectuns to Revision 0 appnwed Rowision 0 w. cd pressure retanng components per Referer:ce 2.
per Reference 1.
and budding structure.
F1.20 :
Wold connechons to buikkng strucsure.
Fim Wald and mcchanecal connechons atintermediate Pnts in mulbconnected entegral and non-ntegralse F1A0 Component trapiarwnent seengs of guases and stops, mesabgnment of supports, assembly of support items.
F-8 Linear type supports F2.10 Mechsnecalconnectons to pressure retanno components end building structure.
F2.20 Weld connochons to building structure.
l F2m wed and mochenecer connechons atintermedete jnents in multmonnected integra!
and non-meegrai supports.
F2A0 -
Compment displacement j
seengs atgunses and stops, j
maalignmers of supports.
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' O-ATTACHMENT 1 inservce inspeden ISI Pmgram Relief Requests Summary RR-09
.F-C Comparent standard F3.10 Mechenecalconnections to Revenson 0 apprW Reveen 0 appecM
- (cont) supports preneure retrwung -,w t
per Reference 2.
per Reference 1.
and bundng structure.
F3.20 '
Weld connochons to budding structure.
T connectons atintermodate i
jomes in mulkconneded integral axi nor>-integras supports.
3-L b.M setangs atguedes and stops.
meangnment of supports, assemth of support name.
F3.50 Spnng type supports, constant load type supports, shock absorbers,hydraubeand mecherncel type snubbers.
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-RR-10 B-F Pressure Retarung Dessmeer B5.130 NPS 4 or Larger Dommeer Metal Revesen 0 Rewmen 0 approved MetalWeids ButtWeids (Pipeg) ressrmed per per Reference 1.-
Neference 2.
RR-11 B-H integral Attachments for P'.10 RaarenrVesselIntegracy Wolded Approved 3W88 as Rovassort 0 dened vesseis Attachments RR-2.4.6.
per Reference 1; welds are accesable Not reouomised witi toliquid penetrant Reference 2 update exan netons due to densiof Unit 2 RR-10 Rev.O por Reference 1.
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ATTAOSENT 1 :
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Limonck Generahng Stehen.' Units 1 and 2, ineence inspechan St Program RoEsf Requests Summary RR-12 :
,WA ASME Code Case (s)
N/A MA Revieson 0 densed 8 Revisen0 approved Authonzahon Parpe por Reference 2-per Reference 1:-
Cases N-479-1 and -
Cases N-400 witt N-495,- s.-d per..
comment not Reg.Gusde 1.147,
=ppair.hs.to Aw Rev.10.
Class 3;fM61 and; N-479.
Revisson 1 -- s;d 1
per Reference 5;.
Revisson 1 issued by j
Case N61 PECO Energy to incorporate Reference 1 -
r comments.
Cases mW-ity approvai per Reg.
Guide 1.147 Rev 8.
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/sTTACHMENT1 Lirnenck Ga r= ot.g Staton, Units 1 and 2, insennce lepi ISI Program Relef Requests Summary RR-13 C-H All Pressure Retaining Pressure Vessels Revson 0 approved Revisen 0 Components C7.10 Pressure Retammg Cur ar,erits parts-resubmitied as v
C7.20 Pressure Retaanog C ryern. As 13-12 and 13-1.5; Revisen 1 by PECO dened parts:
Energy in (wipc w Piping 13-1.1,13-1.3, to RAI.
C7.30 Pressure Retaining Curpersts 13-1.4,13-1.6 C7.40 Pressure Retaining Cu v ierits 13-1.7,13-1.9, Revision 1 approved
. er 13-1.10,13-1.11, parts:
Pumps 13-1.12,13-1.13, 13-1.2,13-1.3, C7.50 Pressure Retanng Curycr.eiits per Refeiwi,c.e 2.
13-1.4,13-1.5 C7.60 Pressure Retaining Cur or,ents 13-1.6,13-1.7, v
Reason 1 13-1.9.13-1.10 Valves resubmitted as per R~fam r;,= 6.
C7.70 Pressure Retaining Cur ar-erits Revson 2 by PECO v
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C7.80 Pressure Retaining Components Energy in i=ws to RAI.
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D-A Systems in Support of '
D1.10 Pressure Retaining Cur er,mits Reactoi Shutdown Funcien Revision 2 approved l
sddruwie parts:
D-B Systemsin Support of D2.10 Pressure Retanng Cur erierits 13-1.3,13-1.4, v
Emergency Core Cooling, 13-1.6,13-1.7, Containment Heat Removal, 13-1.10,13-1.11, Atmosphere Cleanup, and -
per Refa a,ca 6.
Reactor Residual Heat Removal D -C Systems in Support of D3.10 Pressure Retaining Cw.yenerits -
Residual Heat Reraoval Fro n Spent Fuel Storage Pool RR-14 N/A Augmerfted Eunisiatui N/A NA Revson 0 N/A is....ininj g.er T
Programs Reference 2.
RR-16 N/A ASME Code Case (s)
N/A N/A N/A Revson 1 owroved AuttuL.oiica Request per R_f;. caw 5; Case N-416-1.
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Pa9e 7 of 8 AT7 ACHMENT1 9
trnenck Gore aik g Statm. Units 1 and 2.
Inservice inspectm ISI W Relief Requests Summary RR-17 N/A ASME Code Case (s)
N/A N/A N/A l P' N O approved
-:.. sence 4; Authonzation Request
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' ': ' :ase N-416-1
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only.
RR-18 N/A ASME Code Case (s)
-N/A N/A N/A Revism O approved Authuii<.ot;cii Request per Refeiern,a 3; use of Case N-516 for Spent Fuel Pooi j
Rerack Modification.
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RR-22 N/A ASME Code Case (s)
N/A N/A Revision 1 appivved N/A l
Authorizate Request per Reference 5; Case N416-1.
RR-23 N/A ASME Code Case (s)
N/A N/A Revision 0 appiuved N/A Authuiis.aiivi Request per R ' ern; 7; alternative to Case N-498-1 for specific HP3 Systems.
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Page C of 8 ATTACHMENT 1 s
trnerick Gera a6g Station Units 1 and 2 Insennce inspechon ISI Program Relief Regtests Summary Rcferences:
Limenck Generating Station, Unit 2 (TAC No. 76091), dated April 23,1991.
2.
USNRC SER for Docket No. 50-352. First Ten Year Intervai inservice inspect.on Program.
Umer;ck Generating Station, Unit 1 (T AC Nos. M84108, M86310 and ME6311), daled March 1,1994.
3.
USNRC SER for Docket No. 50-353, inspecbon Program Regarding Dry Welding Requinanents, l
Limenck Generating Statui, Unit 2 (TAC No. M90496), dated October 28,1994.
4.
USNRC SER for Docket No.53-353, Approval of Oode Case N-416-1 as an Afterna'e to the Required Hyd u4.a. Pressure Test (RP-17)
Limenck Generating Station, Unit 2 (TAC No. M31230), dated February 1,1993.
5.
USNRC SER for Docket Nos. 50-352 and EO-353. Relief Request RR-12 (Revision 1), RR-22 (Revision 1), and RR-16 (Revision 1),
Lirrenck Generating Station, Unsts 1 and 2 (TAC Nos. M91712 and M91713), dated June 29.1995.
6.
USNRC SER for Docket Nos. FO-352 and 50-353 Evaktation of Relief Request No.13 for, i
Limerick Generating Station Units 1 and 2 (TAC Nos. M91714 and M91715), dadd October 5,1995.
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USNRC SER for Docket No. 50-352. Rerwar Reg sest No. 23 for Limerick Generating Stat'on, Und 1 (TAC No. M93209), dated January 17,1996.
- 8. ' USNRG SER for Docket Nos. "XI-352 and 50-353. EvatusSon of the Secand Ten-Yea" interval Ird,pecikwi Program Plan j
Request for Altemative to insendce Ins;;s: tion and insennca Testing Pruw E=TE Updata for.
Limenck Generating Station, Units 1 and 2 (TAC Nos. M92393 and M92394), dated anuary 23,1994 9.
USNRC SER for Docket Nos. 50-352 and 50-353. Refef Request for Use of ASME Code Case N-546 in the Insen,ta inspecbon Program for.
Limenck Generating Station, Units 1 snd 2 (TAC Nos. M99343 and M99'N5), dated October 9,1997.
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Limerick Generating station, Units 1 and 2,
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- Code Cases Applicable to the 181 and Repair and Replacement Prrgrams
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Page1of 1 ATTACHMENT 2 Limerick Generating Station, Units i and 2 Code Cases Applicable to the ISI and Repair and Replacement Progiams Code Approved Case Title by USNRC
. Number Reg. Guide 1.147
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N-2361 Repair and Replacement of Class MC Vessels Yes H
Note 1,2
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t N 3071 Revised Ultrasonic Examination Volume for Class 1 Bolting, Table IWB-Yas 25001 Examination Category B G 1, When the Exarrinations Are Conducted From tt.e Center Drilled Hoie N 323-1 Attemative Examination for Welded attachments to Pressum Vessels No Note 5 N 389 __
Altemative Rules for Repairs, Replacements, or Modifications Yes N-406 Altemate Rules for Replacement Yes N-4161 Altemative Pressure Test Requirement for Welded Repairs or Installat6on of No Rglacement items by Welding, Class 1,2 and 3 Note 3 N-47.7 Code Cases in inspection Plans Yes N 435-1 Alternative Examination Requirements for Vessels with Wall Thickness 2 in.
Yes or Less N-460 Altemative Examination Coverage for Class 1 and Class 2 Wolds Yes N 461 Alternate Rules for Piping Calibration Block Thickness Yes N-4_79 1 Boiling Water Reactor (BWR) Main Steam Hydrostatic Test Yes N-495 Hydrostatic Testing of Relie! Valves Yes N-498-1 Altemative Rules for 10 Year Hydrostatic Pressure Testing No Nobs 2.5 N-5161
'Onderwater Welding No Note 4 N 524 Altametive Examination Requireiaents for LongitoCinal Welds in Class 1 and -
No 2 Piping No'* 5 N 546 Altemative Requirements for Qualification of VT 2 Examinat6on Personnel
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Note 2 N 566 Corrective Action for Leakage Identified at Bolted Connections No Note 5 NOTES:
- 11. Limited to Article 2000 for Leakage Test following repairs, replacements or modihcations. Effective September 9,1996, all other aspects of Primary Containment repairs, replacements or modifications sh all be updated from ASME Section XI, Subsection IWC,1986 Edition to Subsections IWE and IWL, 1992 Edition with 1992 Addenda per 10CFR50 Rule Making dated August 8,1996.
2.
This Code Case has not been endorsed for usa by the USNRC in Reg. Guide 1.147. See Relief Request RR 12 for justification of its use in this program.
- 3. This Code Case has not been endorsed for use by the USNRC in Reg. Guide 1.147. Limerick specific approval to use this Code Case was provideo by the SER for Relief Request RR-22 (Unit 1) and RR 16 (Unit 2). These Relief Requests have since been mcorporated into the Limerick ISI Programs as part of Relief Request RR 12.
4.
Pending. Request to use proposed alternativo per 10CFR50.55a(s)(3) submitted to the USNRC by l i 5._ _ Pending. Request to use proposed attemative per 10CFRSO.55a(a)(3) submitted to the USNRC by letter dated July 18,1997, leiter dated January 30,1998.
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_ATTACHMENTi3
- Limerick Generat6ng Station, Units 1 and 2
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-'m Revised Relief Requests RR 01, RR-05, RR 11; RR 15 and RR 23 e
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LCS Units 1 and 2 ASMC Section XI Prograro Appendix A. RR-01 Page 1 of 13 RELIEF REQUEST No. RR-01 Revision 2 (This is a complete rewrite) 1.
IDENTIFICATION OF COMPONENTS Class 1 pressure retalning circumferential and longitudinal shell welds in the reactor pressure vessel, Examination Category B A, item Numbers B1,11 and 81.12 respectively.
11.
CODE REQUIREMENTS FROM WHICH REllEF IS REQUESTED ASME Section XI 1980 Edition, Examinallon Category B A requiren s volumetrio examination of essentially 100% of the weld length of all circumferential and longitudinal shell welds during the First inservice inspection (ISI) Interval. The Limerick Generating Station ASME Section XI ISI Programs and later approved Editions of the ASME Section XI Code require that these same examinations be performed during the successive (Second) Inspection Interval. Examinations shall be performed in accordance with Figures IWB 25001and 2 (as applicable) and the nondastructive examination requirements of ASME Section V, Article 4, paragraph 7-441.3.2. The ASME requirements are supplemented by Regulatory Guide 1.150, Issued by the US Nuclear
)
Regulatory Commission (USNRC).
Section XI of the ASME Boller and Pressure Vessei Code requires inservice inspection (ISI) of Reactor Pressuro Vessel (RPV) assembly wolds. At Limerick, these Examinations were performed using Ultrasonic (UT) techniques.Section XI regulies
- essentially 100%" of the weld lengths to be examined. The Code of Federal Regulations,10CFR50.55a, was amended on September 8,1992. The new rulemaking defined "Escer,tlally 100%" as any amount greater than 90% of the weld length. The rule also requires submittat of information and proposed attematJve examinations when the > 90% requirement can nct be met. The rule applies to Code Category B A, item No. B1.10. welds. Item B1.10 welds are the assembly welds in the reactor pressure -
vessel shell.
The RPV design at timeilck piohibits examining 100% of the ASME Weld and Required Volume (WRV) of some welds. Code Case N-400 defines how the
- essentially 100%" requirement is to be calculated. An additive limliation of up to 10% of the weld length is permitted. USNRC Regulatory Guide 1.147 spproved Ccde Cass N 460 for use by Licensees. In accordance with 10CFR50.55a, a relief request is necessary for welds where the > 90% requirement can not be rnet.
Relief is requested from the First inspection interval reautrement for complete examinathn of LGS Unit i shell circumferential weld 'AD* and for approval to use ths proposed alternative Second inspection interval plan for LGS Units 1 and 2 Examination Ca'egory B-A welde as listed in Table FR-01 1. Complete Code examination of these welds is not practical due to limitations imposed by reactor pressure vessvi design und radiation exposure to exarnination personnel.
111.
BASIS FOR RElgf Complete examination of the subject welds is not practical due to scanning limitations and access restrictions from various RPV appurtenances (such as adjacent RPV nozzles, integral attachments and the biologict4 shield wall)and for ALARA considerations.
1 LGS Units 1 and 2 ASME Section XI Programs Appendix A, RR-01 Page 2 of 13 REllEF REQUEST No. RR-01 Revision 2 cont'd PECO Energy intended to perform RPV examination.; w?th an automated Ultrasonic (UT) system, wherever possible, at Limerick. During the Preservice Inspection (PSI), it became apparent that manual exeminations were required in areas where access for the automated system was restricted. The manual exams were performed to assure the maximum possible coverage for these Baselina examlnstions. It wcs recognized that this might not be posslDie during lSt.
Many manual examinat!ons were required on LGS Units 1 and 2 to achieve the required coverage during the First inspection Interval. This resulted a significant increase in personnel radiation exposure, above what was planned. Additionally, insulation had to be removed to allow access to the manual exam areas, also resulting in a significant increase in personnel radiation exposure.
r In many cases, the insulation was not designed to be rernoved. This resulted in several areas of crushed and otherwise damaged mirrv insulation. Also, some non removable insulation supports interfere with a major portion of one weld (circumferential weld 'AD*).
PECO Energy workinn with its NDE contractor, jointly developed a philasophy that addressed issues such as tr:
exams, equipment improvements, possible attemative examinations, etc.
It was decided that changes to RPV examinat!on methods should result in increase'i examination coverage and decreased radiation exposure to personnel. Manual examinations would not be routinely performed in interference areas. Rather, each case would hs analyzed to determine whether manual exams could reach the stated goal of increasing coverage to >90% without significant increase in personnel exposure. Where it was possible to achieve the required coverage, without exceeding ALARA planning goals for the weld, manual examinations were performed.
Changes, except for the switch to the GERIS 2000 digital UT systein, were made incrementally.
Lessons learned from examinations on Unit 1 were applied to Unit 2 and vice versa. Because of the lessons teamed on Unit 1, fewer manuel examinations woro performed on Unit 2. This accounts for the slight differ 6nces in coverage for identical welds on each Unit.
The refinement of scanning equipment was ongoing during the First inspection interv6. Major improvements include a Mini-scanner that can access areas where manual examinat ons were required previously, an in line r,earch unit package that allow 1 accets to some restricted areas, aad a re-design of the standard search unit package to improve coverago.
The result of these ac9vitios has been a continuing improvement in overall performance, during the First inspection Interval. There has been a noticeable increase in examination coverage and a significant decrease in personnel exposure. It is expected that this philosophy and scanning equipment refinements will continue to be applied throughout each Unit's Second Inspect'on Interval.
The RPV assembly welds for Limerick Units i nd 2 are contained in three (3) bub assemblies.
The locations and identification of each weld is t.hnwn on the Weld Maps. The sub assemblies are identified as the Closure (Top) Head, the Bottom Head, and the Vessel Shell. The total weld
' lengths for each sub-assembly are listed below, along with the percentage exP. mined. There are minor differences between Unit 1 and 2. These are identified in Table RR-01 1 and are described below.
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LGS Units 1 and 2 ASME Section XI Programs Appendix A. RR-01 Page 3 of 13 REl.5 REQUEST IJo. RR-01 Revision 2 cont'd RPV Closure Hud. Units i and 2 The RPV Closure Head was fal:ncated usine two (2) circumferential and six (6) meridional welds.
The totai circumferent,al weld length is 1272.1", The total meridional weld length is 483.0", All welds arc considered to bs accer.sible. Essentially 100% of each weld has been examined during the First Inspection interval in accordance with ASME Section XI requirements.
1he totallanoth of all welds in the Closuro Head is 1755.1",
BP_V Bottom Hepf Unit 1 The RPV Bottom Head wes fabneated using one (1) circumferential and seven (7) meridional welds. The circumferedial w3ld length is 688.0". The total meridional weld length is 721.0", of which 462.0"is accessible for e amination. Essentially 100% of the accessible portion of each weld has been examined during the First inspe.tlon Interval in accordance with ASME Section XI requiremonus.
The major poition of weld DG, the dollar piate meridional weld, is made inaccessible by Control Rod Drive (CRD) housings. Wold DG is 262.0"long, with 75.0" (37.5" at each end) accessible.
Table IWB-2500-1 requires examination tf the " accessible portion" of meridional welds, 75.0" (the accessible portion) of the weld was examit.ed. Essentially 100% of this weld has been examined during the First inspection Interval in accordance with ASME Saction XI requirements.
A portion of wolds DA, DB, DC, DD, DE, and DF, the side plate eneridional welds, was made inaccessible by the Sepport Skirt Kwckle (an attachment weld) welded over the seams. These welds are 76.5"long, with 64.5" accessible. Table IWB-25001 requires examination of the "accessit,'e portion" of merldlonal wolds. 64.5" (the axessible portion) of each weld was examined. Essentially 1M% of each weld has been examined during the First inspectivn Interval in acordance with ASME Section XI requirements.
The t stallength of all welds in the Bottom Head is 1409.0". The " accessible portion" of these welds is 1150.0",
RPV Bottom Heat Unit 2 The RPV Bottom Head was fabricated using one (1) circumferential and eight (8) merldlonal welds. The circumferential weld length is 688.0". The total meridional weld length is 914.2", of which 462.0"is accessible for examination. Essentially 100% of the accessible portion of each weld has been examined during th9 First inspection Interval in accordance with ASME Section XI requirements.
The major portion of welds DG-13 and DG 14, the dollar plate meridional welds,is made inaccessible by Control Rod Drive (CRD) housings. These welds are 227.6"long, with 75.0*
accessible. Table IWB-25001 requires examination of the " accessible portion" of merldlonal welds. 75.0"(the accessible potilon) of the weld was examined. Essentially 100% of this weld has been examined riuring the First inspection Interval in accordance with ASME Section XI requirements.
el,
LGS Units 1 and 2 ASME Se; tion XI Programs Appendix A. RR 01 Page 4 of 13 REUEF REQUEST No. RR-01 Revision 2 cont'd A podion of welds DA, DB, DC, DD, DE, and DF, the side plate morldional wolds, was made inaccessible by the Support Skirt Knuckle (an attachment weld) welded over the seams. These welds are 76.5"long, with 64.5"accessiblo. Table IWB 25001 requires examination of the
" accessible portion" of meridional welds. 64.5" (tha accessible portion) of each weld was r
examined. Essentially 100% of each weld has been examined during the First inspection interval in accordance with ASME Section XI requirements.
The totallength of all welds in the Bottom Head is 1602.2", The
- accessible portion" of these welds is 1150.0".
RPV Shell. Units 1 and 2 The RPV Shell was fabricated t: sing slx (6) circumferential and thirteen (13) longitudinal weida.
The total circumferential weld len0th is 5028.0". The total long!tudinal weld length is 1590.6". All welds are considered to be accessible. With the exception of Unit 1 circumferential weld "AD",
essentially 100% of each weld has been examined durin0 the First inspection Interval in accordance with ASME Section XI and 10CFR50 augmented requirements.
Nozzle N17B was installed dire:t!y through longitudinal weld BF, While this shell course is 137.0" high, only 101.9" of the weld remains Ccvorage calculations fer this weld are based on the 101.0" tength, The totallength of all welds in the RPV Shell is 6619.5". The " accessible portion" of these welds is 6584 4".
The technical basis for this request for inspection relief is documented in the report *BWR Vessel and Internals Project, BWR Reactor Prossure Vessel Shell Weld Inspection Recommendations (DWRVIP-05)", that was transmitted to the NRC in September 1995.
The independent NRC assessment of BWRVIP 05 utilized the FAVOR code to perfomi a probabilistic fracture mechanics (PFM) analysis to estimate,*tPV failure probabilities. Three key assumptions in the PFM analysis are; 1)the neutron fluence was that estimated to be end-of.
license mean fluence; 2)the chemistry values are mean values based on vessel types and; 3)the potential for beyond design basis events is considered. Although BWRVIP-05 provides the technical basis supporting the relief request, tne following information is provided to show the conservatisms of the NRC ana!ysis relative to the Reactor Pressure Vessels.
LGS Units 1 and 2 are defined as ASTM E 105-73, Case "A" plants, since the vessels have a predicted shift in the reference nll-duct;itty temperature (ARTc) of less than 100*F and will be exposed to a neutron fluence of less than 5x10 n/cm over the design lifetime of the plant. The 2
expected low RPV 1/4T 32 EFPY beltl!no fluence ("5x10 n/cm ) results in a low predicted shift 2
in the reference nil-ductility temperature, RTa (<60*F at 32 EFPY).
The chemistry factor, ART, NDT, margin term, mean ART, and upper bouild ART are calculated consistent with the guidelines of Regulatory Guide 1.99, Rev. 2. The combination of the NI% and Cu% were used to determine the Chemistry Factor, which is iteelf bounded by the NRC IndepenJent Assessment.
LGS LWts 1 and 2 ASME Section Xi I,wimma Appendix A. RR 01 Page 5 of 13 RELir F REQtJEST No. flR 01 Revision 2 cont'd Considering the expected shift in RTa (ARTc)is ame'l and the excellent LGS Units 1 and 2 plate and weld chem!stry, embrittlement due to fluence effects have e negligible affect on the LOS Units 1 and 2 reactor pressure vessel weld failure probabilities.
At en August 8,1997 meeting with the industry, the NRC staff indicatcd that the potential for, and consequences of, non-design basis events not addressed in the BWRVIP-05 report should be considered, in particular, the NRC staff stated that non-design basis, cold, over pressure transients should be considered, it is highly unlikely that a BWR would experience a cold, over-pressure transient. At the Augt.st 8,1997 meeting, the NRC s'aff described several types of events that could be procursors' k BWR RPV cold, over pressure transients. These were identified as precursors Locause no cold, over-pressure event has occurred at a U.S. BWR, Also at the August 8 meeting, the NRC staff identified one actual cold, over pressure event that occurred during shutdown at a non-U.S. BWR. This event apparently included seve,al operational errors that resulted in a maximum RPV pressure of 1150 psl with a temperature range of 79'F to 88'F.
As provided in the following discussion, PECO Erargy has in place procedure, which monitor and centrol reactor pressure, temperature, and water inventory during all aspects of cold shutdown which would minimize the likelihood of a low Temperature Over Pressurization (LTOP) event from occurring. Additionally, there procrdures are rsinforced through operator trHning.
The Leakage Pressure Test and the Hydrostatic Pressure Test procedures which have aeen used at LGS, have sufficient procedural guidance to prevent a cold, over pressurization event. The Leakage Pressure Test is performed at the conclusion of each outage, while the Hydrostatic Pressure Test is performed once every ten years. The leakage and hydrotests are infrequently-performed, complex ' asks, and the test procedures are considered Plant Evolution / Special Tests. As such. a requirement is included in thern for operations management to perform a " pre.
briefing" with all essential personnel. This briefing details the anticipated testing evolution with special emphasis on-conservative decision making, plant safety awareness, lessons leamed from similar in-house or industry operating experiences, the importance of open communications, and, finally, the process in which the test would be aborted if plant systems responded in an edvcree manner. Vessel temperature and pressure are required to be monitored throughout these testo to ensure compliance with the Technical Specification pressure-temperature curve. Also, the procedures require the designation of a Test Coordinator for the duration of the test who is a single point of accountability, responsible for the coordination of to,,y
+om initiation to closure.
and maintaining Shift Management and line management cognizant
. )e status of the test.
Additional;/, to ensure a controlled, deliberate pressure increase, the rate of pressure increase is administratively limited throughout the performance of the test. If the pressurization rate exceeds this limit, direction is provided to romove the CRD pumps, which are used for pressurization, from service.
l.GS Units 1 and 2 ASME Section XI Programs Appendix A RR-01 w
Pogo 6 of 13 RELIEF REQUEST No. RR-01 Revision 2 cont'd With regard to inadvertent system injection resulting in an LTOP condition, the high pressure make-up systems (High Pressure Coolant injection (HPCI) and Reactor Core isolatior' Cooling (RCIC) systems, as well as the normal foodwater supply (via the Renctor Feedwater Pumps)) at LGS are all steam driven. Curing reactor cold shutdown conditions, no reactor steam is evallable for the operation of tnese systems. Therefore, it is not possible for these systems to contribute to an over-pressere event while the unit is in cold shutdown.
In the case of low pressure system initiation, the shutoff head for the LOS Core Spray and Restdual Heat Removal Pumps are sufficiently low that the potential for an over pressurization event which would significantly exceed the Tech Spec p' essure-temperature limits, due to an inadvertent actuation of these systems,is very low.
Procedural control is also in place to respond to an unexpected or unexptt.ined rise in reactor water level which could result from a spurious actuation of an injection system. Actions speclined in this procedure include preventing condensate pump injection, securing ECCS system INection, tripping CRD pumps, terminating all other injection sources, and lowering RPV level via the RWCU system.
In addition to procedural barriers, Licensed Operstor Training has been held which further reouces the possibility of the occurrence of LTOP events, initial Licensed Operator Training and Simulator Training of plant heatup and cooldown includes performance of surveillance tests which ensure preosure-temperature curve comp!!ance, in addition, operator training has been provided on the expectations for procedural compliance, as provided for in the Station's Operations Manual.
In addition to the above, continuour review of industry operating plant experiences is conducted to ensure that the PECO Energy procedures consider the impact of actual events, including LTOP events. Appropriate adjustments to the procedures and associated training are then implemented, to preclude similar situations from occurring at LGS.
Based upon the above, the probability of a cold over pressure transient is considered to be less than or equal to that used in the NRC analysis.
The NRC staff has recently transmitted a Request for Additional information (N., garding the BWRVIP 05 report to the BWR Vessel and Intemals Project (BWRVIP). The BWRVIP plans to prowde a response to that RAI in the near future that will include additional information on the BWRVIP Probabilistic Fracture Mechanics (PFM) analysis, comparisons to the NRC staff PFM analysis and additional information regarding beyond design basis cold over pressure transients.
PECO Energy will work with the BWRVIP to resolve thi longer term issues in this area, but believes BWRVIP-05 and the NRC analysis provide sufficient basis to support this relief request.
The circumferentiai and longitudinal shell welds are examined using automated ultrasonic examination techniques to the maximum extent practical. Supplemental manual examinatinns may yleid increases in examination coverage; however, these increases come at a cost of increased personnel radiation exposure. Thorofure, due to ALARA consideratiens, supplemental manual ultrasonic examinations are not being considered to augment automated examination coverage.
I t
LGS Units i snd 2 ASME Section XI Programs Appendix A. RR 01 Page 7 of 13 RELIEF REQUEST No. RR-01 Revision 2 cont'd Based on tho documentation in BWRVIP-05, the risk informed independent assessment performed by the N9C staff and the dircussion above, PECO Energy believes that rollef from the Firm Inspoction interval requirement for complete examination of LGS Unit 1 shell circumferential wold *AD" and app oval to use the proposed attemative Second inspection Interval plan for LGS Units 1 and 2 Examination Category B-A welds as listed in Table RR-01 1, is justified.
IV.
6LTfSNATE PROVISION _S Pursuant to 10CFR50.55a(a)(3)(l), PECO Energy considers the following attemate 3.mvisions to be practical for the subject weld examinations. Pt:CO Energy believes that, with the enhanceme'1tn in ultrasonic scanning equipment that PECO Energy has supported during the First inspection Interval, ASME Code coverage can be achieved with automated UT systems without the ne3d for supplomental manual enminations. However, due to the limited experience with the full compliment of improved scanners, the Second 10 Year interval Planned Coverage lirted in Table RR 01 1 identifies only the absolute minimum examination coverage that will be achieved.
RPV Shell Wolds Circumferential Weldr Weld AA Perform entire weld with automated system. No manual exams should be required.
Weld AB Perform entire weld with automated system. No manual excms should be required.
Weld AC Perform entire wold with automated system. No manual exams should be required.
Weld AD Perform limited (a 75%) of weld volume with automated dystem. File Relief Request for 25% of the wold volume due to insulation, bl3 shield and stabilizer design. Note that 100% of the weld length is examined, but scan distance is effected. No manual exams should be performed.
Weld AE Perform entire weld with automated system. No manual exams should be required.
Wold AF Perform Bottom Side of weld with automated system. Continue O' from sealing surface.
Lonaltudinal Welds Shell Course 1 Welds BA, BB, and BC Perfomi entire weld with automated system. No manual a
exams should be required.
Shell Course 2 Welds BD, BE, and BF Perform entire weld with automated system. No manual exama should be required.
Shell Course 3 Welds BG, BH, and BJ Perform entire weld with automated system. No manual exams should be required.
Shell Course 4 Welds BK and BM PerforH entire weld with automated system. No manual exams should be required.
Shell( ourse 5 Welds BN and BP Perform entiro weld with automated system. No manual exams should be required.
LGS Units 1 ano 2 l
ASME Section XI Programs Appendix A. RR-01 Page 8 of 13 i
t RELIEF Rt! QUEST No. RR-01 j
Revision 2 cont'd l
Closure Head Wolds fdrgumferentialWelda Welds AG and AH Con'inue manualexaminations.
Side Plate Meridional Welds DH, DJ, DK, DM, DN, and DP Continue manual examinations.
Bottom Head Welds CircumferentialWeld Weld AJ Continue manual examinations.
Side Plate Meridional Welds DA, DB, DC, DD, DE, and DF Continue manual examinations.
Dollar Plate Meridional Welds DG13 and DG14 Continue manual examinations
m.
LGS Unas 1 and2 ASME Secton XI Programs AppencEx A.RR-01 Page 9 of13 SHELL CIRCUMFERENTIALWELDS and SHELLTO FLANGE VELD W eld Code W eld l Autornated Manual First 10 Year Ir:terval Sew.-410 Year intervai ID ltem Length l
Coverage Coverage ActualCoverage P;anned Coverage AA B 1.11 835.3" Unit 1:562%
Unit 1: 43.8%
Unit 1: OwTposite = 100%
=8.5%
Unit 2: 89.5%
Unit 2: 10.5%
Unit 2-CwTpcsae = 100%
AB B 1.11 835.3" Unit 1: 97.7%
Unit 1: 0.0%
Unit 1: Composite = 97.7%
~
=
.1 %
w.o Unit 2-9G.1%
Unc 2- 0.0%
Unit 2: Composde = 96.1%
AC B 1.11 835.3" Unit 1:902%
Unit 1: 9.8'7.
Unit 1: Cuir nte = 100%
ma
= 86.8%
i Unit 2-86.3%
Unit 2-6.4%
Unit 2-Composi'e = 932%
AD B 1.11 8373"
' Un11:59.6%
Unit 1: 283%
Unit 1: CwTposite = 87.9%
~
Unit 2-77.0%
Unit 2-18.9%
Unit 2-Composite = 95.9%
AE B 1.11 642.0" Unit 1: 77.7%
Unit 1: 22.3%
Unit 1: CO,Tpcsite e 100%
= 803 Unit 2: 802%
Unit 2: 19.7%
Unit 2-Composite = 99.9%
i AF B 1.30 842.0" Unit 1: 0%
Uc:t 1: 99.1%
Und 1: Manual = 99.1%
Unit 2-21.o'%
Unit 2-75.0%
Unit 2: Composite = 96.6%
l
_ _ _ _. _ _ _ _ +.. _
LGS Unas 1 and2 ASME Sedian XI Programs Appendix A.RR-01 Page 10 of 13 SHELL LONGITUDINALWELDS W eld Code W eld Automated Manual First 10 Year bterval Sm.w.d 10 Year Irv' d ID ltem Length Coverage Coverage Actual Coverage P'apsd Coverage BA B 1.12 13T Unit 1: 85.4%
Unit 1:14.6%
Unit 1:Cui A = 100%
Auth = 85.5 Und 2-85.8%
Unit 2:14.2%
UnR 2-CuvA = 100%
BB B 1.12 13T Unit 1: 852%
Und 1: 14.8%
Und 1:CuiM = 100%
M = 855 Unit 2: 84.9%
UnR 2-15.1%
Unit 2-Composite = 100%
BC B 1.12 13T Unit 1: 72.8%
Unit 1:272%
'Jnit 1: Composde = 100%
= 72.8%
Unit 2-70.3%
Unit 2: 29.7%
Und 2-Composde = 100%
BD B 1.12 13T Ur:it 1: 100%
Und 1:0%
Und 1: Automated = 100%
- I Unit 2:100%
Unit 2:0%
Unit 2-Autornated = 100%
BE B 1.12 13T Unit 1: 100%
Unit 1:0%
Unit 1: Auternated = 100%
- I Unit 2-100%
Unit 2: 0%
Unit 2-Automated = 100% '
BF B 1.12 103" Unit 1: 772%
Und 1: 22.8%
Und 1: CwWs = 100%
M = 89_%
Unit 2: 89.8%
Unit 2: 102%
Unit 2-Composde = 100%
BG B 1.12 13T Urvi1: 85.9%
Und 1: 14.1%
Und 1: Cuip = 100%
Unit 2- 01.7%
Unit 2-16.1%
Unit 2-Composde = 97.8%
8
%U
@W y;W ~
t V3 Urh 1 and'a ASME S.t" or XI Prp e.pe4xlix A, RR-01 Page 11 of 13 SHEL1. LONGITUDINAL WELDS cont.
W eld Code W eld Automated Manual First 10 Year interval Eecond 10 Year Interval f
iD ltem Lnngth Coverage Coverage ActualCoverage Planned Coverage BH B 1.12 137" Ur !:02.5%
Unit 1: 0%
Unit 1: Automated = 100%
matM = 915%
Unit 2: 92.5%
Unit 2: 0%
Unit 2-Automated = 100%
BJ B 1.12 137" Unit 1: 90.4%
Unit 1: 9.6%
Unit 1: Composite = 100%
mated = M.4%
Unit 2: 96.4%
Unit 2:0%
Unit 2-Automated = 96.4%
BK B 1.12 86* -
_ Unit 1: S1.3%
Unit 1: 48.7%
Uqst 1: Composite = 100%
M matM = 51M Unit 2-28.3%
' Unit 2: 71.7%
Unit 2-Composite = 100%
~
BM B 1.12 86"
~ ~ ~
Unit 1: 50.0%
Unit 1: 50.0%
Unit 1: Composite = 100%
M mated = MM Unit 2: 28.0%
Unit 2: 72.0%
Unit 2: Composite = 100%
BN B 1.12 92.8" Unit 1: 0%
Unit 1: 100%
Unit 1: Manua! = 100%
maw = 76M Unit 176.5%
Unit 2: 23.5%
Unit 2: Composite = 100%
BP B 1.12 92.8" Unit 1: 0%
Unit 1: 100%
Unit 1: Manual = 100%
cmated = 98.8%
Unit 2: 98.8%
Unit 2- 0%
Unit 2: Composite = 98.8%
L
O 4
6 e
LGS Unas 1'and2.
ASME Sechon XI Pnvams Appendix A. RR-01 Page 12 of 13 I
OLOSURE HEAD CIRCUMFERENTIAL WELDS. MERIDIONAL WELDS and HEAD to FLANGE WELD Weld Code W eld Automated Manual Frst 10 Year interval Sm,wd 10 Year Interval'
. lD '
Item Length Coverage Coverage Actual Coverage Manned Coverage AG B 1.49 765.3" Unit 1:0%
Unit 1:100%MT Unit 1: MT = 100%
92.3% UT Manual UT= 92.3%
MT = 100%
nual = 92.3%
Unit 2:0%
Unit 2:100%MT Unit 2 MT = 100%
92.3% UT Manual UT= 92.3%
AH B 1.21 506.8" Unit 1: 0%
t.' nit 1: 100%
Unit 1: Manuai = 100%
amat=1M Unit 2: 0%
Unit 2: 100%
Unit 2: Manual = 100%
DH B122 80.5" Unit 1: 0%
Unit 1: 100%
Unit 1: Manual = 100%
anual = 1M Unit 2: 0%
tJnit 2:100%
Unit 2: Manual = 100%
~
DJ B 1.22 80.0" Unit 1: U%.
Unit 1: 100%
Unit 1: Manual = 100%
"I Unit 2: 0%
Unit 2: 100%
Unit 2: Manual = 100%
DK B 1.22 80.5" Unit 1:0%
Unit 1: 100%
Unit 1: Manual = 100%
anual = 1M Unit 2:0%
Unit 2: 100%
Unit 2 Manual = 100%
DM B 1.22 80.5" Unit 1:0%
Unit 1: 100%
Unit 1: Manual = 100%
mat = 1M Unit 2:0%
Unit 2 100%
Unit 2-Manusi = 100%
DN B 122 80.5" Unit 1: 0%
Unit 1: 100%
Unit 1: Manual = 100%
amai r i%
Unit 2: 0%
Unit 2: 100%
Unit 7-Manual = 100% -
DP B 122 80.5" Unit 1: 0%
Unit 1: 100%
Unit 1: Manual = 100%
Unit 2: 0%
Unit 2: 100%
Unit 2: Manual = 100%
y 3
u n
LGS Units 1 and2
- ASME Sechon XI Persgrams Appendix A. RR-01 Ptge 13 of 13 BOTTOM HEAD l
CIRCUMFERENTIAL WELDS and MERIDIONAL WELDS I
l W eld i Code W eld Automatmi Manual First 10 Year Interval Second 10 Yearinterval ID ltem Length Coverage Coverage Actual Coverage Planned Coverage
~
AJ B 1.21 688.0" Unit 1:0%
Unit 1: 100%
Unit 1: Manual = 100%
nual = 100%
Unit 2: 0%
Unit 2: 130%
Unit 2: Manual = 100%
DA B 1.22 76.5" Unit 1: 0%
Unit 1: 100%
Unit 1: Manual = 103%
Manual = 100%
64.4 s
Unit 2: 0%
Unit 2: 100%
Unit 2-Manum = 100%.
g uc e LB B122 76.5" -
Unit 1:0%
'Unt 1: 100%
Unit 1: Manual-100%
Manual = 100%
4' Unit 2: 0%
Unit 2 100%
Unit 2: Manual = 100%
uc e e DC B 1.22 76.5" Unit 1:0%
Unit 1: 100 %
Uni' 1: Manual = 100%
Manual = 100%
64.4" s
Unit 2: 0%
Unit 2: 100%
Un i2: Manual = 100%
u e,
DD B 122 76.5" Unit 1: 0%
Unit 1: 100%
Urit 1: Manual = 100%
Manual = 100%
4 ss Unit 2: 0%
Unit P: 100 %
U.it 2-Manual = 100%
9 e DE B122 76.5" Unit 1: 0%
Unit 1: 100%
Unit 1: Manual = 100%
Manual = 100%
- 64.4* Accessible Len th Oue Unit 2: 0%
Unit 2 100%
Unit 2: Manual = 100%
DF S 1.22 76.5" Unit 1: 0%
Unit 1: 100%
Unit 1: Manual = 100%
Manual = 100%
s Unit 2: 0%
Unit 2: 100%
Unit 2: Manual = 100%
u e Unit 1 only B 1.22 262.0"
. Unit 1: 0%
Unit 1: 100$b Unit 1: Manual = 100%
Manual = 100%
DG0*
- 75.0" Accessible Length Due DG 180*
to CRD Housings Iinit 2 only 8 1.22 227.6" Unit 2- 0%
d5t 2: 100%
U i t 2: Manual = 10(f%
Manual = 100%
UG130*
- 52.0" Accessible Length Due DG13180*
to CRD Housings Unit 2 only B 1.22 227.6" Unit 2:0%
Unit 2: 100%
. Unit 2-Manual = 100%
Manual = 100%
DG14 0*
- 52.C' Accessible LengQ Due DG14180*
to CRD Housings 3
tn 4 4
LGS Units 1 end 2 AS AE Section XI Progrtms Appendix A. RR-05 y
Page 1 of 2 RELIEF REQUEST No. RR-05 Revision 2 (Thh is a complete rewrite) 1.
IDENTIFICATION OF COMPONENTS Class 2 integrally welded attachments for vessels, and pumps, Examination Categorv C-C.
11.
CODE REQUIREMENTS FRCM WHICH RIl.lEF IS REQUESTED ASME Section XI 1986 Edition, Examination Category C-C requires a surface examination of 100% of required areas of each welded attachment to vessels, piping, pumps and valves, in the case of multiple vessels, only the integrally welded attachments of one (1) vessel in a group of vessels of similar design and service (or the equivalent of one vessel) need be examined.
E Examinations shall be performed in accorJance with Figure IWC 2500-5 using the nondestructive 6Xamination (NDE) requirements cf ASME Section V.
Ro!ief is requested to perform the required examinations in accordance with ASME Section XI, 1995 Edition with the 1996 Addenda, Table IWC-2500-1. Examination Category C-C.
111.
BASIS FOR RELIEF
\\
Access for examination equipment is limited by component configuration or installed support
\\
members.
1 During the First inspection tr,terval, attempts to perform alti, mate NDE methods, e.g. L' quid Penetraat (PT) or Ultrasonic Testing (UT) Class 2 integral attachment welds proved unsuccessful.
Neither NDE metnod resulted in an increase in examination coverage (in fact UT resulted in less
.r coverage), in add l tion, there was a significant increase in radiation exposure to both examination and support personnel due to the weld surface preparation requirements and increased examination times associated with these methods. Also, insta!!ed support members caused the same access limitations regardless of the NDE method used.
All welds were examined to the maximurr. extent practical. Increased examination coverage is not possible without undue hardship, such as a plant modification.
Tne 1995 Edition of ASME Section XI has recognized these generic access lin.itations and has appropriately modified the Examinatbn Requirements. Table IWC-25004 Examination Category C-C, ha:: also include Note (6) which requires examir ation of the integret attachment welds whenever component support member defc,rrration is identfied.
a E
l-
.: 2 LGS Unit < t and 2 ASME Section Xi t>rograms Appendix A. RR-05 Page 2 of 2 ~
RELIEF REQUEST No. RR-05 Revision 2 cont'd Moption of PECO Energy's proposed altemative will result in a reduction in radiation exposure to examination and support personnel and will reduce the number of welds requiring rel'ef requests due f.o incompleta examination coverage '.,ased solely on the requiren; ants of the 1986 Edition of the ASME Sectivn XI Code. These e.'we.ative rules are based on the 1995 Edition of the Code, and as such, provide an acceptable level of quality and safety which does not compromise the adequac" of the LGS Units 1 and 2 ASME Section XI Programs In meeting the intent of the ASME Code.-
IV.
ALTERNATE PROVISIONS PECO Energy will perform the required examinations of Class 2 integral attachment welds in
. accordance with ASME Section XI,1995 Edition with the 1996 Addenda, Table IWC-2500-1, _
Examiriation Category C-C.
LGS Units 1 and 2 ASME Section XI Programs Appendix A, RR-11 Page 1 of 2 RELIEF REQUEST No. RR 11 Revision 1 (This is a complete rewrite) 1.
IDENTIFICATION OF COMPONENTS Class 1, integrally welded attachments to the reactor pressure vossal, Examination Category B-H, and integrally welded attachments to piping, pumps and valves, Examination Category B-K-1.
11.
CODE PEQUIREMENTS FROM WHICH RELIEF IS REQUdSTED ASME Section XI 1986 Edition, Examination Categories S-H and B-K-1 require a surface -
examination of essentially 100% of the weld length of all Class 1 integrally welded attachmentc.
Volumetric examinations may be performed in lieu of surface examinations as specified in the applicable Table IWB-25001, Notes. Examinations shall be in accordance with Figures IWB-2500-13,14 and/or 15 as applicablo using the nondestructive examination (NDE) requirements of ASME Section V.
Relief is requested to penorm the required examinations in accordance with ASME Secdon XI, 1995 Edition with the 1996 Addenda, Table hVB-2500-1, Examination Category B-K as supplemented bu Code Case N-323-1, Altemative Examination For welded Attachments to Pressure Vessels, for Figure Nos. lWB-2500-13 and IWB 2500-14.
111.
BASIS FOR REllEF Access to ths reactor ptassure vessel stabilizar bracket attachment welds is limited due to mirror insulation support members affixed to the stabilizer bracket lugs and the stabilizer assembly support members. These suoport members preclude equipment access necessary for complete maOnetic particle examination of the weld and required area.
Access for examinatkx squipment is also limited in the area of skirt attachment weld build-up.
The configuration of the RPV skirt knucklo to the bottom head limits access for complete examination of the underside of the weld, Access for examination of Class 1 piping integral attachment welds is limited due to installed support members.
During the First inspection Interval, attempts to perform both Liquid Penetrant (PT) and Ultrasonic Testing (UT) o' the reactor pressure vessel integral attachment welds proved unsuccessful.
Neither NDE method resulted in an increase in examination coverage (in fact UT resulted in less coverage). Also, there was s significant increase in radiation exposure to both examination and support personnel due to the veld surface preparation requirements and increased examinatinn times associated with these methods.
In the case of the piping integral attachment welds, the installed support members caused the same access limitations regardless of the NDE method used.
LGS Units 1 cnd 2 ASME Section XI Programs Appendix A. RR 11 Page 2 of 2 RELIEF REQUEST No. RR-11 Ruiston 1 cont'd The 1995 Edlilon of ASME Section X!Iand Code Case N-32'i-1) has reccgnized these generic access I;mitations and have appropriat'ely modified the. Examination Requirements. Table IWB-2500-1 Examination Category B-K, has also included Note (6) which requires examination of the Integral attachment welds whenever component support member deformation is identified.
Adoption of PECO Energy's propos ad attemative will result in a reduction in radiation exposure to examination and support personnel and will reduce the number of welds requiring relief requests due to incomplete examination coverage based solely on the requirements of the 1986 Edition of the ASME Section XI Code. These altemath e rule rea based on the 1995 Edition of the Code, and as such, provide an acceptable level of quality and safety which does not compromise the adequacy of the LGS Units 1 and 2 ASME Section XI Programs in meeting the intent of the ASME Code.
IV.
ALTERNATE PROVISIONS PECO Energy will perform the required examMations of Class 1 integral attachment welds in accordance wit!' ASME Section X;,1995 Edition with tiie 1996 Addenda, Table IWB-2500-1, Examination Category B-K as supplemented by Code Case N 323-1, Altemative Examination For welded Attachments to Pressure Vessels (for Examinatior. Requirements / Figure Nos. lWB-2500-13 and IWB-2500-14).
m,"
LGS Units 1 and 2 ^
ASME Section XI Programs Appendix A RR 12 Page 1 of 11.
- RELIEF REQUEST No. RR 12; Revision 2 li SCOPE
= This relief request is applicable to those ASME Code Cases ted for use in the LGS Units 1 4 and 2 ASME Se': tion XI Programs which have not been a ly endorsed for use by the -
LUSNRC in _ Regulatory Guide 1.147, 1 11. --
DISCUSSION Code Cases are periodically published by the ASME for the purpose of either clarifying' the intent :
J
' of Code rules or for provid rules and regulations for circumstances which are not currently-covered by exis Code but need to be addressed in a i manner. Use of these -
ten-mandatory C ases for inservice inspectinn is subject to U NRC acceptance of the Code
-- Case (s); Regulatory Guida 1.147 lists those Codes C sos that I ave been reviewed by the NRCi and are generally acceptable for implementation in an ASME Section X' Program. Other Code ~
' Cases may bw used provided specific authorization is requested pursuant to 10CFR50.55a.
c.The purpose of this relief request is to request authorization of the adoption of spe.ific Code -
^
Cases for imp'ementation in the LGS ASME Section XI Programs.
E llf, CODE CASES REQUIRING AUTHORIZATION
?The following Code Cases require specific authorization for use in the LGS ASME Section XI Programs:
?/
N-416-1' Altemative Pressure Test Requirement for V/elded Repairs or Installation of Replacement items by Welding, Class 1,2 and 3.
t : See Table RR-12-1 for discussion on aopucability to the LGS Units 1 and 2 ASME ~
l Section XI ams.'
,2.. Use of this C Case was authorized per USNRC SER for Docket Nos. 50-352 and ~
50-353, Relief Request RR-12 (Revision 1), RR-22 (Revision 1), and RR-16 (Revision 1), Limerick Generating Station' Units 1 and 2 (TAC Nos. M91712 and M91713, dated June 29,1995.
" Revision 1; n
. B.-
' N-498-1 Altemative Rules for 10 Year Hydrostatic Pressure Testing
=*
. 1. See Table RR-12-2 for discussion on applicability to the LGS Unit 1 and 2 ASME -
m Section XI Programs.
2.
Use of this Code Case was suthorized per USNRC SER for Docket Nos. 50-352 and 50-353, Relief Request RR-12 (Revision 1), RR-22 (Revision 1), and RR-16 ie
. (Revision 1), Limerick Generating Station, Units 1 and 2 (TAC Nos. M91712 and r
M91713), dated June 29,1995. -
L 3.
Previous request was for LGS Unit 1, only. Use of this Code Case for LGS Unit 2 is 9
- pending USNRC approval. Table RR 12-2 is being resubmitted with this correspondence to request additional approval for use of the Code Case with the LGS Unit 2 ASME Section XI Programs.
)
m
y ggg 3
g-ASME Section XI Programs Appendix A. RR 12 D_
M, n
- Page 2 of 11 1
g
~
RELIEF REQUEST No. RR-12 Revision 2 cont'd s
'O.
- N 546 Altemative Requirements for Qualification of VT 2 Examination Personnel '
^
1.
See Table RR-12-3 for discussion on applicability to the LGS Unit 1 and 2 ASME:
Section XI Programsc
- 2. Use of this Code Case was authorized per USNRC SER for Docket Nos. 50-352 and 50-353, Relief Requost for Use of ASME Code Case N 546 in the Inservice
= Inspection Prg340), dated October 9,1g3tation, Units 1 and 2 (TAC Nos.
m for, Limerick Generet' M99343 and
~
D.-
N-524 = Altemative Examination Requirements for Longitudinal Wolds in Class 1 and 2 _
- Piping.
Section XI P W Use of this C Case is pending USNRC approval. Table RR-_12-4 is being
- submitted with this correspondence to r uest approval for use of the Code Case with the LGS Units 1 and 2 ASME Section XI 3
E
' N-566 Conctive Action for Leakage identified at Bolted Connections.
- 1. -See Table RR-12 5 for discussion on applicability to the LGS Unit 1 and 2 ASME Section XI Pr 2.
Use of this C Case is pending USNRC approval. Table RR-12 5 is being submitted with this correspondence to request approval for use of the Code Case with
~ the LGS Units 1 and 2 ASME Section XI Programs.
[
IV.
ALTERNATE PROVISIONS
- The altamative rules of the Code Cases in til above shall be incorporated into the Code Baser. fori l the LGS Units 1 and 2 ASME Section XI P--
siis and shall be implemented in accordance v Ith --
- Relief Raquest RR-12 unts such time as tMode Cases are incorporated into Regulatory Guide -
1.147 or an approved version of the Section XI Code.
~ V. _
BASIS FOR RELIEF i All of the Code Cases discussed in 111 above epresent technically acceptable altamative ruiss to 1
~ ASME Section XI Code requirements. The fact that these Code Cases have not been endorsed in the Regulatory Guide in no way detracts from their technical adequacy since the major reanon for
- their omission is the timing of their publication with respect to the most recent revision of the 4-
- Regula Guide. That is, the subject Code Cases are relatively recent end it is expected that -
these C Cases will be accepted in a subsequent revision of the Regulatory Guide.
Adoption of these altamative rules provides'an acceptable level of quality and safety and does not L coinpiviidae the adequacy of the LGS Units 1 and 2 ASME Section XI Programs in meeting the -
^ >
Jintent of the ASME Cooe.
1
^
J 4
w.
LGS Units 1 ant; 2 -
' ASME Sectica XI Programs Appendix A. RR Page 3 of 11
= RELIEF R'iQUEST No. RR-12 Tsbie RR 12-1
- r
. Code Case N-4161
. l.
IDENTIFICATION OF COMPONENTS ASME Clacs 1,2, and 3 Pressure Retaining Components sul' ject to Hydrostatic Testirg per_ IWA--
- 4400 and IWA-5000, h
ill.
LCODE REQUIREMENTS FROM WHICH RELIEF IS REQUESTED ASME Code, Section XI-1986 Edition, lWA-4400 requires an elevated pressure hydrostatic test to p
- be performe,1 after repairs by welding, or the installation of replacement items by welding, on the
_ pressure retaining boundary of Class 1,2, and 3 components.
lli. -
BASIS FOR RELIEF Elevated pressure hydrostatic tests are d;fficult to perform end oftsa represent a true hardship.
Some of the difficulties associated w,.h elevated pressure testing include the following:
I>
. ~ Hydrostatic testing often requires complicated or abnormal valve line-ups in order to property vent, hit, and isolate the component requiring testing.
- e Relief valves with setpoints lower than the hydrostatic test pressurn must be gr.gged, or removed and blind flanged. The removal and flanging process requires th; eminlag and '
- refilling of the system.'
Valves that are not normally used for Isolation (der to allow for pressurization.normally op
- ~
require t% consuming seat maintenance in or
. - The radiatiun exposure required to perform a hydrostatic pressure test is high due te the large amount of time required to prepare the system for testing (install relief valve gags, perferm '
appropriate valve line-ups, etc.).
r 1 The difficulties encountered in performing a hydrostatic pressure tex are prohibitive when'
- weighed against the benefits. Industry experience shows that most through wall leakage is detected during system operation as opposed to during elevated pressure tests such as 10-year hydrostatic tests.
' Little benefit is gained from the added challenge to the piping system provided by an elevated.
pressure test, when compared to an operational test, Lapecially when one considers that the piping stress experiencert during a hydrostatic test does noiinclude the significant stresses-associated with the thermal growth and dynamic loading associated with design basis, e
I
ASME dection XI Programs Appendix A. RR 12 -
' Page 4 of 11 -
RELIEF REQUEST No. i<R-12 Table rtR 121 cont'd-
_ Code Case N-416 : w
.IV.-
ALTERNATE PROVISIONS The alternateprovlsions of ASME Section XI Code Cose N 416-1, Altemative Pressure Test Requirement for W91ded Repairs or Installation of Replacement items by Welding, Class 1,2 and
' 3 may be us4 to perform pressure testing associated with ASME Section XI Repairs and Replacements as follows:
NDE shall be performed in accordence with the methods and acceptance criteria of the e
- applicab!e Subsection of the Construction Code (e.g. ASME Section Ill).
When performing reosirs b welding, or tha instauation of replacement items by welding, on.
E eo
- the pressure retainirig bou of Class 3 components, NDE shall be performed in,
accordance with the methods and acceptance criteria of the Construction Code (e.g. ASME :
1 Section 11:) In addition, when an examination is used in accordance with the Construction
- Code for butt and socket welded joints, an additional surface examination (Magnetic Particle or Liquid Penetrant) (MT/PT) shall be performed or the root i. ass layer when surface -
examination is required by the Construction Codc fer the final weld. This provision does not i s 1
. apply to Class 1 and 2 compone..ts, since examinations wiil be performed in accordance with '
Code requirements.
Prior to or immediateiy tipon return to service, a visual examination (VT-2) shall be performed in conjunction with a system leakage test (functional or inservice), in accerdance with ~
- paragraph IWA-5000, with no hold times.
,y r
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,,I
.g x
.' \\
= - -
.. LGS Units 1 'and 2"
- ASME Section Xt Programs -
Appendix A RR,,
Page 5 of 11a RELIEF REQUEST Noi RR 12 3 Table RR-12 2 -
- Coda Case N498-1:
1.
SCOPE
( ASMl! Class 1,2, and 3 Pmscure v4etaining Cor da Cubject to 10-Year Hydrostatic Pressure _'
- Testing per Tables IWO, IWC, IWD-25001 aN A-5000
- il
' QQDFJEQVlBEMEliTfFROM WHICH RELIEF IS REOWGEQ,.
f ASME Code,'Section X!,1986 Edition Tables IWD,IWC,IWD-2500-1 require the performance of an
- aleva46 pressulv hydrostatic test, once_each inspecion interval on the pressure retair,ing bourMary..
- j
? of Class 1,2, and 3 compononts.--
' 11 0 BASIS FOR RELIFE o
W Adoption of C@ Case N498-1 will s'Mnate the need for the performance of the ' Class 1,2, and 3.
NS
- once per inspectW1 Interval HydrostaWinst at multiples of the system design sbre, as sequ' red by ASME Boiler and Pressure Vessel (B&PV) Code,Section XI, thert so the amount of -
radiation exposure received during the perfoi vice of the C 1,2, and 3 hydrostatic -
1 4 Coda Case N-498-1 represents tachnically acceptable attemet.ve rules to ASME Section XI Code i
_ 1 requiremer's The fact that this Code Case has not been irrdorsed in the Rergulatory Guide in no '
-5
- way detracts from its technical adequacy since the major reason inr its omissica is the timing of its -
' publication with respect to tne most recent revision of the Regulatory Guide. That is, the subject
, 1 the Regulatory Guide.y recent and it ' expected that it will be accepted in a subsequent revision
- Codo Caseis relativel ~
a
=
i Adoption of this attemative rule provides an acceptable level of quanty and safety and does not E
,a L comgromise the adequacy of the LGS ASME Section XI Programe in meeting the intent of the ASME --
-- r-
. Code.
b
, s IV.1 ALTERtyjg PROVISIONS' k ^"
'As an altamative, a Class 1 system leakage test shall be conducted at or near the end of the ~
Inspection interval. The boundary subject to test pressurization dunng the system lee age test sha'l g'
'3 p
' er'end to all C! ass 1 pressure retainig wiipOn66ts within the system boundary, in utdtbn, a -
4 Class 2 and 3 system pressure test wij be conducted at or near the and of the 1,1 erval. The '
8 boundary subject to test pressurization during the system pressure test will extend to all Class 2 and -
K
- 3 components required to operate or support the safety system function up to and including the first.
3 normally closed valve, includmg a safety or relief valve or valve capable of automatic closure when i
- the safety function is required. --
4
^
A=
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_69' s
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l.
p?G, q
LGS Unns 1 and 2 -
ASMS Section XI Programs Appendix A. RR 12 Page 6 of 11 RELIEF REQUEST No RR 12 Table RR 12-3 Code Case N 546
- l. :
IDENTiFICATIQN OF COMPONENTS None v
l!.
CODE REQUIREMENTS FROM WHICH REllEF IS RF.OVESTED ASME Section XI, IWA-2300, requires that personnel performing VT-2 visual examinations be qualified in accordance with comparable levels of competency as defined in ANSI N45.2.6.
Additionalty, IWA 2300 requires tha examination personnel shall have natural or corrected naar
- distance vision act.ity, in at least one eye, equivalent to a Snellen fraction of 20/20. For far vision, personnel sholl have natural or corrected far distance visual aculty of Snellen 20/30 or equivalent.
These examin tion personnel shall e'so have a color vision examination to verify the capability to distinguish color and differentiating contrast between the colors used in the applicable method.
Personnel vision examinations shall be conducted annually.
2
- PECO Energy requests approval to implement Code Case N 543,"Altemative Requirements for Qualification of VT 2 Examination Personnel,' which is not yet approved by reference in Regulatory Guide 1.147.
111.
BASIS FOR RELIE.E
- Code Case N-546 allows experienced plant personnel such as licensed and nonlicensed operators, local leak rate y;rsonnel. systarn engineers, and inspection and nondestructive examination personnel to perform VT-2 visual examinations without having to be ccrtified to comparable levels of competency defined in ANSI N452.6. The PE(.O Energy Company individuals performing the visual examinations will be subject to the conditions pn vided in Code Case N-5.t6.
Specifically, the examination personnel will have at lesst 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> of plant walkdown experience, receive a minimum of four hours of training on Section XI requirements and plant specific procedures C
for VT-2 visual examinations, and will pass the vision test requirements of IWA-2321,1995 edition, in addition to the requirements in Code Case N-546, PF^9 Energy Company has procedures to assure that consistent VT-2 visual examinations are p6:tumed. PECO Energy Company will continue to document the qualifications, training, and visual acuity
- VT-2 examinations and maintain records that verify all of the requ,0f persons selected to perform the -
irements in the Code Case as specified herein, are met.' This altamative to the current code requirements alleviates the need to contract certified VT 2 personnel to perform these examinations and reduces the administrative
' burden of maintaining an extensive Section XI qualification and certification program for VT-2
- examination personnel.
p Code Case N-546 represents technica;./ acceptable altemative rules to ASME Section XI Cod 6 j "c requirements The fact that this Code Case has not been endorsed in the Regulatory Guide in no way detracts f;om its tetnical adequacy since the major reason for its omission is the timin of its publication with respect to the most recent revision of the Regulatory Guide. That is, the su Code Case is relatively recer;t and it is expected that it will be accepted in a subsequent rev lon of
. the RecJery Guide L
Q' c
m -
g M.,6 ?
. LGS Units 1 and 2 '
- ASME Section XI Programs -
Appendix A. RR 12 Page 7 of11 RELIEF REQUEST No. RR-12 Table RR-12 3 cont'd -
Code Case N 546 Adoption of this altemative rule provides an acceptable level of quality and safety and does not -
compromise the adequacy of the LGS ASME Section XI Programs in meeting the intent of the ASME __
1 Code.
N.
ALTERNATE PRO /ISIONS
- PECO Energy Corppany will meet the requirements contained in Code Case N-546, iditionally, PECO Energy Company has formal procedures so that consistent VT-2 visual examinations are performed, e,nct will document and maintain records to verify that persons selected as VT-2 examiners are quellfled.- Gee of this code case will provide a comparable level of quality and safety to that currently in place for VT-2 visual examulations.
F t
t
LGS Units 1 and 2 ASME Section XI Programs Appendix A, RR-12 Page 8 of i1 REllEF REQUESTNo. RR 12 Table RP-12-4 Code Crse N 524 1.
IDENTIFICATION OF COMPONENTS ASME Class 1 and 2 Longitudinal Wolds in piping subjed to r,ondestructive examination per Tables lWB, and IWC-2500-1.
11.
CODE REQUIREMENTS FROM WH:CH RELIEF IS REQtlESIFD ASME Codo,Section XI,1986 Edition, Tables IWB-2500-1, Category B-J, and IWC-2500-1, Categories C-F-1 and C-F-2 require surface and volumetric examination of pipe longitudinal welds for a specified distance along the pipe beyond the iritersection with the pipe circumferential weld.
Ill.
BASIS FOR RELIEF
.4 Adoption of CODE Case N-524 w!Il limit the surface and volumetric examination requirements of Class 1 and 2 longitudinal welds to the area or volume contained within the Weld and Required Volume (WRV) examinadon requirements of the intersecting circumferential wtsid thereby, reducin0 the amount of personnel radiation exposure received by extmination and support personnel during the performance of the required nondestructive examinations.
The examination of these welds during the First inspection interval has resulted in significant radiation exposure to personnel that exceeded PECO Energy's exposure budget. The total-radiation exposure associated with the examination of longitudinal welds i Jependent on the tinie required to remove and reinstall insulation, adjacent supports and other interferences, prepare the weld for examination, and perform the examinations.
Longitudinal welds are not produced in the field or fabrication shops as is the case of a circumferential weld. Longitudinal piping welds for Class 1 and 2 applications were made by the pipe manufacturer under controlled conditions which produced high quality welds and uniform residual stress pattems. These welds were examined in accordance with the appropriate ASTM or ASME specifications with additional nondestructivo examination requirernents imposed by the purchasing specifications. The manufacturing controls specified by the appropriate ASTM or ASME specifications along with the additional examinations imposed by the purchasing specification provides assurance of the structural integrity of the longttudinal weld at the time the pipe is manufactured.
Nondestructive examinations performed during the Preservice inspection and First interval inservice Inspections have not shown any fabrication or service induced flaws and as such have provided assurance of the structural integrity of the 'ongitudinal welds in ;he LGS Unitt 1 and 2 piping systems. Based on results of these inspections, continued examination of longitudinal welds beyond the WRV of the intersecting circumferenth! weld by Code Case N-524 is not warranted, if any degradation associated with a longitudinal weld were to occur, it is expected to occur in the areas of higher stress located at the intersection with a circumferential weld. The inspection of this intersection is within the scope of this Code Case.
I
LGS Units 1 and 2 ASME Section XI Programs Appendix A. Rh-12 s
Page 9 of 11 RELIEF REQUEST No. RR-12 Table RR-12-4 cont'd Code Case N-524
)
Code Case N 524 epresents technically acceptable attemative rules to ASME Section XI Code requirements. Tht,6xt that this Code Caso has not been endorsed in the Regulatory Guide in no way detracts from its technical adoRuacy since the major reason for its omission is the timing of its publication with respect to the most recent revision of the Regulatory Guide. That is, the subject Code Case is relatrvely recent and it is expected that it will be accepted in a subsequent revision of the Regulatory Guide.
Adoption of this alternativa rule provides an acceptoble leven of quality and safety and does not compromise the adequacy of the LGS ASME Section XI Programs in meeting the intent of the ASME Code.
IV.
ALTERNATIVE PROVISIONS PECO Energy proposes to use the altemative provisions of Code Case N-524 for the examination of longitudinal welds in Class 1 and 2 piping systems. The Code required examinations of longitudinal welds shall be performed in the vsa/ volume defined by the WRV of the in;ctsecting circumierential weld.
LGS Units 1 end 2 ASME Section XI Progrtms Appendix A. RR 12 Page 10 of 11 RELIEF REQUEST No RR-12 Table RR 12-5 Code Case N-566 I.
IDENTIFICATION OF COMPONENTS ASME Class 1,2, and 3 Pressure Rotalning Bolted Connections.
l 11.
CODE REQUIREMENTS FROM WHICH RELIEF IS REQUESTED ASME Code,Section XI,1986 Edition, IWA-5250(a)(2) requires that if lokage occurs at a bolted connection, the bolting shall be removed, VT-3 visually examined for conosion, and evaluated in accordance with IWA 3100.
111.
BASIS FOR RELIEF Removal of pressure retaining botting at mechanical connections for visual, VT-3 examination and subsequent evaluation, in locations where leakage has been identified, is not always the most discerning course of action to determine the acceptability of the bolting. The Code requirement to removo, examine, and evaluate bolting in this situation does not allow PECO Energy to consider other factors which may indicato the acceptability of mechanical joint bolting.
Other factors which should be considered when evaluating botting acceptability when leakage has been identified at a mechanical joint include, but are not limited to. joint bolting material, service age of joint bolting materials, location of the leakage, history of leakage at the joint, ev>!3nce of l
corrosion with the joint assembled, and corrosiveness of process flu:d.
Performance of the pressure test while tha system is in service may identify leakage at a bolted connection that, upon evaluation, may conclude the integrity and pressure retaiaing ability of the joint is not challenged it would not be prudent to negatively impact the availability of a safety system by removing the system from service to adcress a leak that does not challenge the system's ability to perform its safety function.
Code Case B566 represents technically acceptable altemative rules to ASME Section XI Code requirements. The fact that this Code Case P.as not been endorsed in the Regulatory Guide in no way detracts from its technical adequacy since the major reason for its omission is the timing of its publication with respect to the most recent revision of the Regulatory Guide. That is, the subject Code Case is relatively recent and it is expecteo that it will be accepted in a subsequent revisiort af the Regulatory Guide.
Adoption of this attemative rule provides an acceptable level of quality and safety and does not compromise the adequacy of the LGS ASME Section XI Programs in meeting the intent of the ASME Code.
LGS Units 1 and 2 ASME Section XI Programs P
Appendix A. RR 12 Page 11 of 11 RELIEF REQUEST No. RR-12 Table RR 12 5 cont'd Code Case N-566
)
IV.
ALTERNATIVE PROVISIONS When leakage is identified at Class 1. 2, or 3 bolted connections by VT-2 visual examination during system pressure testing, an evaluation will be perforraed to determine the susceptibility of the bolting to corrosion and assess the potential for failure. The evaluation will, et a minimum, consider the following factors:
- 1.
Bolting materials 2.
Corrosiveness of process fluid leaking 3.
Leakage locetion 4.
Leakage history at connection or other system components
- 5. Visual evidence of conosion at connection (while connection 's assembled) j 6.
Service age of bolting materials When the possure test is performed on a sys em that is in service or that Technical Specifications require to be operable, and the bolting is susceptible to corrosion, the evaluation shall address the connection's structuial integrity until the next component / system outage of sufficient duration. If the evaluation concludes the system can perform its safoty related function, removal of the bolt c!osest to the source of the leakage and a VT 3 visual examnation of the bolt will be performed when the system or component is taken out of service for a sufficient duration (to accomp;;sh other system maintenance activities).
For bolting that is susceptible to corrosion, and when the initial evaluation indicates that the connection cannoj conclusively perform its safety function until the next component / system outage of sufficient duration, the bc!t closest to the source of the leakage wsl be removed, (
VT-3 visual examination will be performed and evaluated in accordance with IWA-3100(a).
LGS Units 1 and 2 ASME Section XI Programs Appendix A. RR-23 Page I of 6 RELIEF REQUEST No. RR-23 Revision 1 1.
IDENTIFICATION OF COMPONENTS d
Class 2, High Pressure Coolant Injection (HPCI) Pump Turbine - steam supply / exhaust lines, and assoc!ated drains, vents, and lube oil cooler supply / outlet lines (see Figures RR-231, RR-23-2, RR-23-3 and RR-23-4 attached).
Li CODE REQUIREMENTS FROM WHICH REllEF IS REQUESTQ ASME Section XI Code Case, N-4981 was approved for uce at Limerick Generating Station (LGS),
Unit 1, by NRC Safety Evaluation, dated June 29,1995. Approval to inchide this Code Case in the 8
LGP Unit 2 ASME Code Bases is pending per this corresp'>ndence. Code Cass 498-1 allows a system pressure iest to be conducted on safety class 2 components as an a'temativ system nydrostatic test, required by the ASME Section XI Code, Examination Category C H. The system pressure test a:lemative provided by the Code Case however, requires a 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> hold time at test pressure, before performing the required visual examindon, for components wt ich are insulated. Since the components identified above are insWA, a 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> hold time would be required for this test. Therefore, a reduction in the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> hold time, for both LGS Units 1 and 2, is the l
requirement from which relief is being requested.
Ill.
BASIS FOR ret IEF As a part of the Emergency Core Cooling System (ECCS), tha HPCI System is not required to uperate during normal plant operation. This system is however periodically tested in accordance with other applicable requirements. These periodic tests are conducted to verify the nperability of the appicable components. The functional test conducted for the HPCI Pump and associated turbine steam supply and exhaust system normally includes approximately 90 minties of pump run tirre, in order to satisfy the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> hold time requirement of Code Case N-498-1, the test would require a HPCI Pump run in excess of 5 l>3urs (hold time p' 3 examination time). Running the HPCI System functional test for this length of time is not practical, and. represents aa undue hardship on the facility, without a compensating increase in the level of quality and safety.
Operating the HPCI Pump for the period of time required to satisfy the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> time, would suyect the facility to unnecessarily excessive heat loads. Control of these heat loads, would require the operation of additional safety related eqisipment, and challenge the Technical Specification limitations placed on the maximum allowable Suppression Pool water temperature.
Removal of the insulaiion from the subject components, in o.-der to qualify for,ne 10 minute hold time allowed by the Code Case, would be equally burdensome. The cost associated with insulation removal and reinstallation, including resource diversion, rad,ation exposure, and additional radwaste would not be warrantea.
Additionally, the Section XI periodic pressure test requirements, which have been iniposed on this system during the first inspection interval (Functional Te t, pE,r IWA-5211 (b)), only require a 10 minute hold time.
o.;
LG8 Units 1 and 2 -
ASME Seet!on XI1 rograms 2
3
. Appandix A, RR 23 Page 2 cf 3 RELIEF REQUEST No. RR 23 Revision 1 cont'd Further, the ASME Section XI Committee is in the process of re'Asing Code Case N-4981 to remove the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> hold time requirement. This proposed revision is in recognition of the unusual difficulties and hardship imposed by the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> hold time on certain systems.
IV.
- Al. TERNATE PROVISIONS The system presse e test described in C3de Case N 4981 wdl be conducted as reqb red, except that a 10 minute hold time will be used in lieu of the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> ho:d time requtement. This 10 minute -
hold time will match the hold tirts which has been required for the previousSection XI ISI Program pressure testing of this system.
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