ML20141L913
| ML20141L913 | |
| Person / Time | |
|---|---|
| Site: | Perry  |
| Issue date: | 05/27/1997 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20141L912 | List: |
| References | |
| NUDOCS 9706030160 | |
| Download: ML20141L913 (17) | |
Text
{{#Wiki_filter:. _. _ - __ . . p uo g ug\ UNITED STATES l g j NUCLEAR RESULATORY COMMISSION WASHINGTON, D.C. 30806-0001 O. . . . . /g SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION OF THE FIRST 10-YEAR INTERVAL INSERVICE INSPECTION PROGRAM PLAN RE0 VESTS FOR RELIEF THE CLEVELAND ELECTRIC ILLUMINATING CO. PERRY NUCLEAR POWER PLANT. UNIT NO. 1 DOCKET NO. 50-440
1.0 INTRODUCTION
The Technical Specifications (TSs) for Perry Nuclear Power Plant, Unit No. I states that the inservice inspection of the American Society of Mechanical Engineers (ASME) Code Class 1, 2, and 3 components shall be performed in accordance with Section XI of the ASME Boiler and Pressure Vessel (B&PV) Code and applicable addenda as required by 10 CFR 50.55a(g), except where specific written relief has be.en granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(i). The 10 CFR 50.55a(a)(3) states that alternatives to the requirements of paragraph (g) may be used when authorized by the NRC if (i) the proposed alternatives would provide an acceptable level of quality and safety, or (ii) compliance with the specified requirements would result in hardship or unusual difficulties without a compensating increase in the level of quality and safety. Pursuant to 10 CFR 50.55a(g)(4), ASME Code Class 1, 2, and 3 components (including supports) shall meet the requirements, except the design and access provisions and the pre-service examination requirements, set forth in the ASME Code, Section XI, " Rules for Inservice Inspection of Nuclear Power Plant Components," to the extent practical within the limitations of design, geometry, and materials of construction of the components. The regulations require that inservice examination of components and system pressure tests conducted during the first 10-year interval and subsequent intervals comply with the requirements in the latest edition and addenda of Section XI of the ASME Code incorporated by reference in 10 CFR 50.55a(b), 12 months prior to the start of the 120-month interval, subject to the limitations and modifications listed therein. The applicable edition of Section XI of the ASME Code for the Perry Nuclear Power Plant, Unit No. I first 10-year inservice inspection (ISI) interval is the 1983 Edition through Summer 1983 Addenda. Pursuant to 10 CFR 50.55a(g)(5), if the licensee determines that conformance with an examination requirement of Section XI of the ASME Code is not practical for its facility, information shall be submitted to the Commission in support of that determination and a request made for relief from the ASME Code requirement. .After evaluation of the determination, pursuant to 10 CFR 50.55a(g)(6)(1), the Commission may grant relief and may impose l alternative requirements that are determined to be authorized by law, will not l i ENCLOSURE 1 ' 9706030160 970527 PDR ADOCK 05000440 0 PDR
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l I i endanger life, property, or the common defense and security, and are otherwise in the public interest, giving due consideration'to the burden upon the , licensee that could result if the requirements were imposed. l In a letter dated June 28, 1996, The Cleveland Electric Illuminating Co'. 3 (licensee), submitted to the NRC its first 10-year ISI interval program plan requests for relief for Perry Nuclear Power Plant, Unit No. 1. The licensee j also provided additional information in its letter dated February 12, 1997. Request for Relief IR-022 was withdrawn by the licensee in its letter dated j June 28, 1996. 2.0 EVALUATION The staff, with technical assistance from its contractor, the Idaho National ' Engineering and Environmental Laboratory (INEEL), has evaluated the , information provided by the licensee in support of its first 10-year ISI
- interval program plan requests for relief for Perry Nuclear Power Plant, Unit No. 1. Based on the information submitted, the staff adopts the contractor's conclusions and recommendations presented in the Technical Letter Report (TLR) enclosed.
Request for Relief IR-005 was previously evaluated and granted pursuant to 10 CFR 50.55a(g)(6)(i) in an NRC safety evaluation (SE) dated April 25, 1990. 4 In Revision 1, the licensee added two welds and deleted 11 welds. For Request
- for Relief IR-005, Revision 1, the code requires 100% surface and volumetric
- examination of the subject Class 1 piping welds. The staff determined that component geometry limits access and precludes complete volumetric examination j and the code coverage requirements are impractical for these welds. To meet the code coverage requirements, design modifications would be required to improve access for examination. Imposition of this requirement would create a l significant burden on the licensee.
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The licensee achieved 50% coverage perpendicular to the welds ar.d met the code requirements for coverage parallel to the welt and for the surface examination. The coverage achieved and limitations described are consistent with those in the original evaluation. Therefore, the staff determined that the technical content supporting the impracticality has not changed and relief remains granted pursuant to 10 CFR 50.55a(g)(6)(1). Request for Relief IR-021, Revisions I and 2 were previously evaluated and granted in NRC SEs dated February 14, 1992, and February 24, 1994. In Revision 3, five integral attachments were added and several editorial corrections made. The code requires 100% VT-3 visual examination of the subject integral attachment welds. The staff determined that the attachment welds contained in this request are inaccessible for visual examination. The five new attachment welds are located in penetrations filled with sealant and are inaccessible for VT-3 visual examination. Therefore, the code requirements are impractical for these welds. These penetrations would i
i . . . t require redesign and modification to gain access for examination. Imposition of this requirement would create a burden on the licensee. The limitations described and examination coverage obtained for these attachment welds are consistent with those in the original evaluation. Therefore, the staff determined that the technical content supporting the : impracticality has not changed and relief remains granted pursuant to l 10CFR50.55a(g)(6)(i). The alternative contained in Request for' Relief IR-028, the licensee proposed as an alternative to the code requirement to disassemble valves for VT-3 visual examination of their internal surfaces. The valves will only be examined when they. are disassembled for maintenance, repair, or modification. Snould access be provided to the interiors of any of the valves within these groupings by emergency maintenance, repair, or modification activities prior to the end of the first interval, they will be' examined as required. The code of record for Perry Nuclear Power Plant requires a VT-3 visual examination of the internal surfaces of the subject valves. The staff determined that visual examination of the internal surface necessitates complete disassembly of the valve, which is a major effort requiring many
. manhours of effort from skilled maintenance and inspection personnel, and results in unnecessary radiation exposure. Therefore, requiring the licensee to disassemble valves for the sole purpose of performing visual ensination represents a hardship without a compensating increase in the level of quality and safety. In addition, disassembly increases the potential of damage to ;
valves. Later editions of Section XI (i.e.,1989 and later) do not require disassembly l of valves for the sole purpose of examining the internal surfaces and state i that internal surface visual examination is only required for valves that are ' dissembled for reasons such as maintenance, repair, or volumetric examination. The staff determined that the licensee's proposed alternative to perform the , visual examination of valve body internal surfaces when the valve is disassembled for maintenance, repair, or modifications, provides reasonable assurance of the valve's operational readiness. Therefore, staff determined that the licensee's proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(ii), The code requires for Request for Relief IR-029 that Examination Category B-J, Items 89.11 and B9.12 require 100% volumetric and surface examinations as defined by Figure IWB-2500-8 for circumferential and longitudinal welds in piping 4-inch nominal pipe size and greater. Welds are selected for examination in accordance with Note 1 of Table IWB-2500-1, Examination Category B-J. The staff detec ained that access to these welds is obstructed by jet impingement shields. Limoval of the jet impingement shields is labor and dose intensive (e.g., 3 man-Rem per shield). Imposition of the j requirement would create a significant burden on the licensee. I { I i l
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l The licensee has proposed as an alternative to examine the obstructed welds, it will examine- similar welds that are not high-stress welds. In addition, , Section XI examinations have been performed on identical high-stress welds in ! the reactor recirculation systems where the jet impingement shields are either l not present or are easily removed. The staff determined that significant patterns of inservice degradation would have been detected by the examination of the alternative welds and of identical high-stress welds. Therefore, the staff determined that licensee's proposed alternative provides reasonable assurance of the structural integrity of the reactor recirculation system welds. The staff determined that the licensee's proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(ii). l
3.0 CONCLUSION
S The Comission evaluates determinations that code requirements are impractical. The Comission may grant such relief and may impose alternative requirements as it determines is authorized by law giving due consideration to the burden upon the licensee if the requirements were imposed on the facility. The staff has reviewed the information provided by the licensee for Request l for Relief IR-005, Revision 1, and concludes that component geometry limits access and precludes complete volumetric examination. To meet the code l coverage requirements,. design modifications would be required to improve j access for examination. Imposition of this requirement would create a , significant burden on the licensee. The requested relief is auti.crized by law and will not endanger life or property or the 9 mon defense and security and is otherwise in the public interest. Thus, for Request for Relief IR-0C5, the staff has concluded that the ASME Code requirements are impractical and, , therefore, the relief remains granted pursuant to 10 CFR 50.55a(g)(6)(1). For Request for Relief IR-021, Revision 3, the staff concluded that the attachment welds contained in this request are inaccessible for visual examination. These penetrations would require redesign and modification to i gain access for examination. Imposition of this requirement would create a , burden on the licensee. The requested relief is authorized by law and will I not endanger life or property or the comon defense and security and is otherwise in the public interest. Therefore, for Request for Relief IR-021, the staff has concluded that 'the ASME Code requirements are impractical, and therefore, the relief remains granted pursuant to 10 CFR 50.55a(g)(6)(1). For Requests for Relief IR-028 and IR-029, the staff has concluded that compliance with the ASME Code requirements would result in hardship without a compensating increase in the level of quality and safety. Additionally, the licensee's proposed alternatives will provide reasonable assurance of the operational readiness of the subject systems. Therefore, the licensee's j proposed alternatives are authorized pursuant to 10 CFR 50.55a(a)(3)(ii). I ! Principal Contributor: T. McLellan l Date: May 27, 1997 l
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, TECHNICAL LETTER REPORT ON THE FIRST 10 YEAR INTERVAL INSERVICE INSPECTION REQUESTS FOR RELIEF FOR CENTERIOR ENERGY PERRY NUCLEAR POYE!MLANL.11 NIT _1 DOCKET NUMBER 50 440 l
1.0 INTRODUCTION
By letter dated June 28,1996, the licensee, Centerior Energy, submitted Requests for Relief IR-028 and IR-029 for Perry Nuclear Power Plant (PNPP), Unit 1. Along with these j new requests for relief, the licensee also submitted revised Requests for Relief IR-OO5 (Rev.1) and IR-021 (Rev. 3), and withdrew Request for Relief IR-022 (Rev. 2). Additional information regarding the new and revised requests for relief was requested by the Nuclear l Regulatory Commission (NRC) in a letter dated January 15,1997. The licensee responded to the NRC request for additional information in a letter dated February 12,1997. The Idaho National Engineering and Environmental Laboratory (INEEL) staff has evaluated the information provided by the licensee in support of these requests for relief in the following section. I 2.0 EVALUATION l The first 10-year inservice inspection (ISI) interval for PNPP, Unit 1, began November 13, 1987 and will end November 13,1997. The Code of record for the first interval is the i 1983 Edition through Summer 1983 Addenda of Section XI of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code. The information provided by the licensee in support of the requests for relief has been evaluated and the bases for disposition are documented below. ' \ l 1 , ENCIDSURE 2 1 4 _ . ~
. A. Reauest for Relief IR-005 (Revision 1L Examination Cateaorv B-J. Item B9.11.
Class 1 Circumferential Pinina Walds Note: This request for relief was previously evaluated and granted pursuant to 10 CFR 50.55a(g)(6)(i) in an NRC Safety Evaluation Report (SER) dated April 25, 1990. In Revision 1, two welds were added and eleven welds were deleted. Code Raouirement: Examination Category B-J, item B9.11 requires 100% volumetric and surface examination, as defined by Figure IWB-2500 8, for Class 1 circumfereritial welds in piping 4-inch nominal pipe size and larger. .
' Licensee's Code Relief Reauest: Relief i.: requested from performing the volumetric examination to the extent required by the Code for the welds listed in the table below.
- (Weld IDE &cis24Descriptionf*D ' RLimit$tish?9 ,$ $EsawWdh 1-B33-0012 ' 22" Elbow-to-pump C001 A Geometry 50% Perpendicular 1 -B33-0046 ' 24"x12" Reducer-to-12" pipe Geometry 50% Perpendicular 1-B33-0054 12" Pipe-to-nozzle Geometry 50% Perpendicular 1-B33-0059 12" Pipe-to-nozzle Geometry 50% Perpendicular 1-B33-0074 22" Elbow-to-pump COO 1 A Geometry 50% Perpendicular 1-B33-0100 12" Pipe-to-nozzle Geometry 50% Perpendicular 1-833-0111 12" Pipe-to-nozzle Geometry 50% Perpendicular 1-B33-116 12" Pipe-to-nozzle Geometry 50% Perpendicular 1-B33-0121 12" Pipe-to-nozzle Geometry 50% Perpendicular
- Welds added in Revision 1 Licensee's Basis for Raouestina Relief (as stated):
" Ultrasonic examinations conducted on welds in the recirculation loops which were inlaid and overlaid with corrosion resistant cladding required specialized techniques.
Typical techniques identified in Appendix lil of Section XI proved to be ineffective. 1 i
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. "To overcome the metallurgical properties impeding conventional shear wave ultrasonic transmission, refracted longitudinal wave examinations were employed.
The acoustic properties of refracted longitudinal wave propagation limit the technique to % vee path. The Code required volume necessitates a full vee path through the weld and required volume. s "Therefore, when access to a butt weld was limited to one side only due to component geometry (e.g., pipe to valve) the perpendicular examination is considered to be only 60% complete. l l "During construction, the subject welds were examined in accordance with the l appropriate Code requirements, weld techniques and welders were qualified in accordance with Code requirements, and materials were purchased and traced in l .accordance with the appropriate Code and NRC requirements and guidelines. In l addition, there were no reportable indications during preservice ingpections.
"The pressure boundary passed the required hydrostatic test, and has operated for i a total of about 2006 equivalent full power days between November 1987 and l February 1996 without leakage indication attributable to the subject welds.
"Since the construction, operating conditions and environmental conditions of the j l non-examined portion of the welds are identical to the examined portions, it is 4 reasonable to apply satisfactory results from examined to the non-examined portions.
l "In summary, because of acceptable initial condition, successful code hydrotest and operating experience without related leakage indications, the capability to examine l half of the subject weld volume on a continuing basis, it is concluded that there is ;
- not significant impact on the overall level of plant quality and safety." , l Licensee's Pronosed Alternative
- The Code-required volumetric examination were performed to the extent practical.
Evaluation: The Code requires 100% surface and volumetric examination of the l subject Class 1 piping welds. However, component geometry limits access and precludes complete volumetric examination. Therefore, the Code coverage l requirements are impractical for these welds. To meet the Code coverage requirements, design modifications would be required to improve access for examination. Imposition of this requirement would create a significant burden on the licensee.
- In Revision 1 of this request for relief, the licensee added two welds and deleted I
i 3 f 1
. eleven welds. The result is a net decrease of nine welds from the originally granted request. For the two additional welds, the licensee achieved 50% coverage ' perpendicular to the weld and met the Code requirements for coverage parallel to the weld and for the surface examination. The reduced coverage is due to weld geometry. The coverage achieved and limitations described are consistent with those in the original evaluation. Therefore, it is concluded that the technical content supporting the impracticality has not changed and relief should remain ! granted pursuant to 10 CFR 50.55a(g)(6)(i).
, l B. Raouest for ReliefJR-021 (Revision 3). ExaminaSon Cateaorv D-B Item D2.20. l Class 3 Intearal Utachments - Comoonent Sunoorts and Restraints Note: Revisions 1 and 2 of this relief request were previously evaluated and granted in NRC SERs dated February 14,1992, and February 24,1994. In Revision 3, five integral at't achments were added and several editorial corrections made. ,
Code Reauirement: Examination Category D-B, item D2.20 requires a VT-3 visual examination as defined by Figure IWD-2500-1, for integral attachments (component supports and restraints). Licensee's Code Relief Reauest: Relief is requested from performing the VT-3 visual examination to the extent required by the Code for the components listed in the table below. g s ap < - e ;3 -< ' vpg wf W- se
#NhsturNE "', Component *163 " 1 # Description l'f N tihgb* eris $ IE$gaNU Main Steam 1821-H0050-WA Welded lugs for pipe Underwater, 0% ;
I B21-H0157-WA support geometry l 1821-H0167 WA 1 B21-H0179-WA Emer. Closed 1 P42-H0221-WA Welded lugs for pipe in penetration filled 0% Cooling support w/ sealant 4
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, x < . , ,>s, ;g > 'L%l EliIpstsi$l diC5mMnsit[lD5' ,
IDescNption "'. * ,$ 0t$ M io M ~ 4ExerrSi Emer. Service 1P45-H0643 WA Welded lugs for pipe in penetration filled 0% ) Wtr. support w/ grout 4 Main Steam 1821-H0176-WA Welded lugs for pipe Underwater, 0% l 1 B21-H0128-WA support geometry
- 1 B21-H0156-WA 1 B21-H0158-WA 1 B21-H0156-WA
- 1821-H0173 WA IB21-H0175 WA
, 1B21-H0155 WA 1821-H0168-WA
- 1821-H0120-WA j 1 B21-H0160-WA 1821-H0186-WA i 1821-H0177-WA 1 B21-H0163-WA 1821-H0164 WA
, Fuel Pool 1 G41-H0396-WA Welded lugs for pipe in penetration filled 0% i Cleaning support w/ sealant Emer. Closed 1 P42-H0115 Welded lugs for pipe in penetration filled 50% , Cooling support w/ sealant
- Emer. Service 1P45-HOO22 WA Welded stantion for in penetration filled 0%
l Wtr. pipe support w/ sealant i 1 P45-HOO49-WA Welded Sleeve for pipe support 1 P45-H0127-WA Welded lugs for pipe l 1 P45-H0191-WA 4 1 P45-H0271-WA 1 P45-H0417-WA
- Emer. Closed 2P42 H0024-WA Welded lugs for pipe in penetration filled 66%
Cooling 2P42-HOO25-WA support w/ sealant 5 Emer. Service 1 P45-H0649-WA Welded lugs for pipe in penetration in 0% Wtr support limited access sump 1 P45-H0659-WA Welded lugs for pipe j guide
! Fuel Cleaning 1 G41-H0427-WA' Welded sleeve of One end in 50 %
i Pool pipe anchor penetration filled w/ sealant 5 i a
e e A *ig & . - ge" SW << 4% 9 [S h $CNg JWb$4 6kt$$crheiQ$ *[O$htruction i @IEsarMdl Emer. Closed 1P43-H0234 WA* Welded lugs for pipe in penetration filled 0% Cooling guide w/ sealant Emer. Service 1P45-H0274 WA* Welded lugs for pipe in penetration filled 0% Wtr. guide w/ sealant I P45-H0365-WA* 50%
- Added to Request for Relief IR-021 in Revision 3 Licensee's Basis for Raouestina Relief (as stated):
"The structuralintegrity of the piping pressure boundary was demonstrated during construction by meeting the requirements of the ASME Code Section Ill. All welds were inspected in accordance with the appropriate Code requirements. Weld .
techniques and welders were qualified in accordance with Code requirements and materials were purchased and tagged in accordance with the appropriate Code and NRC requirements and guidelines.
" Complete examinations meeting the requirements of the ASME Code Section XI '
were performed on integral attachments with similar configuration which utilized the same weld techniques, procedures and materials.
"Since the construction and operating conditions of the inaccessible welded attachments are similar to that of welded attachments that were examined, it is reasonable to extend the satisfactory results of the accessible integral attachments to the inaccessible ones.
-The pressure boundary passed the required preservice hydrostatic test and first period inservice system pressure tests, and the plant has operated for the total of about 2,006 equivalent full power days between November 1987 and February 1996.
"In summary, because of acceptable initial condition, successful examinations of similar components, and successful test and operating experience, it is concluded that there is no significant impact on the overall level of plant quality and safety."
Licensee's Proposed Alternative: The subject integral attachments were examined to the extent practicai. Evaluation: The Code requires 100% VT-3 visual examination of the subject integral attachment welds. However, the attachment welds contained in this request are 6
. inaccessible for visual examination. Specifica!!y, the five new attachment welds are located in penetrations filled with saa';nt and are inaccessible for VT-3 visual examination. Therefore, the Code requirements are impractical for these welds. These penetrations would require redesign and modification to gain access for examination. Imposition of this requirement would create a burden on the licensee. The limitations described and examination coverage obtained for these attachment welds are consistent with those in the original evaluation. Therefore, it is concluded that the technical content supporting the impracticality has not changed and relief should remain granted pursuant to 10 CFR 50.55a(g)(6)(i). C. Reauest for Relief IR-022 (Revision 2L Examination Cateaorv F-A Item F3.10. Class 3 Comoonent Suonorts NDitt: This request for relief was withdrawn by the li'censee in the June 28,1996 submittal. D. Reauest for Relief IR-028. Examination Cateaorv B-M-2. Item B12.50. Class 1 Valve Bodies Code Reauirement: Examination Category B M-2, item B12.50 requires a VT-3 visual examination of the internal surfaces of valve bodies exceeding 4-inch nominal pipe size. Licensee's Pronosed Alternative: Pursuant to 10 CFR 50.55a(a)(3)(ii), the licensee proposed an alternative to the Code requirement to disassemble valves for VT-3 visual examination of their internal surfaces. As an alternative, valves will only be examined when they are disassembled for maintenance, repair, or modification. Should access be provided to the interiors of any of the valves within these groupings by emergency maintenance, repair, or modification activities prior to the 7
i . l
; . end of the first interval, they will be examined as required. The applicable valve
- types and groupings are listed in the table below.
1 ( l j 2 +%PE : ~ : #!98tSiISOjQ l
.MMands Ww 9 74$be
$1 g if ^p @ej@@n kg39@tSEPja$3F Sme asy&i:e
%Vahre' Nog g~m System v##%u%s$
j /SSf305 Disenption% WQGioupingg
)a we we mas s jgyp< ma tw , wr nqiR ~< &'--- ; 1B33-F023B RR/602104 22" Gate Valve V ,
1 \
; 1E12-F023 RHR/642-122 6" Globe Valve XV 1E12-F042A RHR/642-126 12" Forged Gate Valve Xil I 2
1E21-F005 LPCS/705-108 12" Forged Gate Valve XVI l
- i. 1 E21-F006 LPCS/705-111 12" Check Valve XVil l 3 i j
1 E22-F036 HPCS/701-111 12" Forged Gate Valve XVill ; i 1E51-F064 RCIC/632-102 10" Forged Gate Valve XXil 1G33-F004 RWCU/671-104 6" Forgod Gate Valve Vill 1 8 1N27-F560A FW/082-102 20" Gate Valve ill , 4 j Licensee's Basis for Reauestino Relief (as stated): J' "The structural integrity of the valves was demonstrated during construction by l meeting the requirements of the ASME Code Section Ill.
"The pressure boundary passed the required hydrostatic test, and has operated for a total of about 2006 equivalent full power days between November 1987 and February 1996, without any leakage indication attributable to the Code boundary of the subject valves.
l j "12 valves, whose interiors were made accessible for examination by maintenance, j repair, or modification activities were examined with satisfactory results. Although ! not of the same groupings, the examined valves are similar in design and function l to the unexamined valves.
"The disassembly of valves solely for the purpou of examination of interior surfaces is impractical in that it is a significant burden without any accompanying i increase in overall plant safety. This is recognized by the ASME Code Committee's i
1 4 8 i 1 i
. removal of this requirement from Section XI in the 1989 Edition and the NRC's current endorsement of the 1989 Edition in 10 CFR 50.55a(g).
"In summary, because of acceptable initial condition, successful Code hydrotest and operating experience without related leakage indications, satisfactory examination results for the examined valves, and NRC endorsement of the 1989
, Edition which no longer requires disassembly solely for examination, it is concluded i that there is no significant impact on the overall level of plant quality and safety." Evaluation: The Code of record for Perry Nuclear Power Plant requires a VT-3 visual l l examination of the internal surfaces of the subject valw,s. However, visual l examination of the internal surface necessitates complete disassembly of the valve, which is a major effort requiring many man hours of effort from skilled maintenance ! and inspection personnel, and results in unnecessary radiation exposure. Therefore, requiring the licensee to disassemble valves for the sole purpose of performing visual exar.7ination represents a hardship without a compensating increasing in the level of quality and safety. In addition, disassembly increases the po.c al of damage to valves. Later editions of Section XI (i.e.,1989 and later) do not require disassembly of valves for the sole purpose of examining the internal surfacts and state that internal surface visual examination is only required for valves that are dissembled for reasons such as maintenance, repair, or volumetric examination. Since the licensee has proposed to perform the visual examination of valve body internal surfaces when the valvs is disassembled for maintenance, repair, or modifications, the licensee's alterrotive will provide reasonable assurance of the L l valves' operational readiness. Therefore, it is recommended that the licensee's proposed alternative be authorized pursuant to 10 CFR 50.55a(a)(3)(ii). E. Reauest for Relief IR-029. Examination Catacorv B J. Items 89.11 and B9.12. Class 1 Pioina Welds
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l , i Code Reauirement: Examination Category B-J, items 89.11 and B9.12 require 100% volumetric and surface examinations as defined by Figure IWB-2500-8 for circumferential and longitudinal welds in piping 4-inch nominal pipe size and greater. , Welds are selected for examination in accordance with Note 1 of Table IWB-2500-4 4 9 1 1 i
_._-_.__.______.m . _ - . . _ _ _ _ . _ _ _ _ _ _ . _ . _ - _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ ,. 1, Examination Category B J. 3 Licensee's Proposed Alternative: Pursuant to 10 CFR 50.55a(a)(3)(ii), the licensee proposes alternative welds in lieu of those specified by IWB-2500, Examination Category B J, Note 1 when examination of high stress welds is obstructed. The I alternative welds selected for examination are of the same size and similar l configuration as those specified in Note 1, but are not high stress welds. The obstructed high stress welds and their alternatives are listed in the table below.
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@NM iWeld lDj% 15$ativeM B9.11 1833-0029 RR/602-101 1 B33-028 16" Pipe to 12"x16" I Sweapolet, CRC -l 89.11 1833-0032 RR/602/101 1B33-0090 16" Pipe to 12"x16" Sweapolet, CRC :
B9.11 1 B33-0043 RR/602/101 1833-0046 12" Pipe-to-Nozzle Safe End, CRC, and B9.12 1833-OO43-U RR/602/101 1B33-0046 D Upstream Long Seam RR = Reactor Recirculation System CRC = Corrosion Resistant Ciad Weld
. = ,
t Licensee's Basis for Reauestina Relief (as stated):
"The welds identified in the attached table are 'high stress' welds, but examination '
is impractical as they are in high radiation areas and are encased in jet impingement shields. The jet impingement shields are elbow or tee shaped structural steel > enclosures around recirculation piping header and riser welds. The jet impingement shields weigh over 1600 lbs and are assembled with 48 high strength, one time use, balts that are tensions to 10-16 kips. Disassembly for inspection, and subst,quent reassembly, is a labor intensive effort that requires over 100 mar,- hours.' Dose rates for the recirculation header piping, in the areas of the shields, range from 200-400 millirem /hr on contact. Thus, removal of each shield results in 1 a dose of approximately 3 rom. 1 "The structuralintegrity of the piping pressure boundary was demonstrated during l construction by meeting the requirements of the ASME Code Section til, and ! additionally by meeting the requirements of ASME Section XI during preservice inspections. The subject welds were examined (prior to installation of the jet impingement shields) in accordance with the appropriate Code requirements, weld 10
)
i
. techniques and welders were qualified in accordance with Code requirements, and materials were purchased and traced in accordance with the appropriate Code and NRC requirements and guidelines. There were no reportable indications during preservice inspection.
"The pressure boundary passed the required preservice hydrostatic test and first period inservice system pressure tests, and has operated for a total of about 2006 squivalent full power days between November 1987 and February 1996 without leakage indication attributable to the subject welds.
l
" Complete examinations meeting the requirements of the ASME Code Section XI l have been performed on identical 'high stress' welds within the Reactor i Recirculation System where jet impingement shields are not present or are easily i removed, with satisfactory results. These welds are subject to the same operating l and environmental conditions as the obstructed welds.
"Other Reactor Recirculation System welds of the same size and configuration, but that are not 'high stress' welds, will be examined in place of the obstructed welds.
In accordance with ASME Research White Paper, Risk Sased Alternative Se/ection Process for Inservice Inspection of LWR Nuclear Power Plant Components, (Library of Congress Catalog Number 94 71660) a recent industry survey, which included ! 50 nuclear units representing 733 cumulative years of operation, found that there is no apparent relationship between the type of welds selected for inspection (i.e., , high design stress / fatigue welds versus low stress / fatigue welds) and the detection of flaws. !
" Design, procurement and operational provisions against ' nil ductile failure of the subject welds remain as described in the Perry USAR.
"In summary, because of the dosa burden, acceptable initial condition, successful ,
Code hydrotest and operating exoerisoce without related leakage indications, the satisfactory examination of identical welds, the substitution of welds of similar size and configuration, and protection against brittle failure, it is concluded that there is no significant impact on the overall levs! of plant quality and safety." Evaluation: The Code requires 100% volumetric and surface examination of the subject Class 1 piping welds. However, access to these welds is obstructed by jet impingement shields. Removal of the jet impingement shields is labor and dose intensive (e.g.,3 man-Rem per shield). Imposition of the requirement would create a significant burden on the licensee. In lieu of examining the obstructed welds, the licensee will examine similar welds
- that are not high stress welds. In addition, Section XI examinations have been
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. performed on identical high stress welds in the reactor recirculation systems where the jet impingement shields are either not present or era easily removed. Any significant patterns of inservice degradation would have been detected by the examination of the alternative welds and of identical high stress welds. Therefore, j reasonable assurance of the structuralintegrity of the reactor recirculation system r welds will be provided and the licensee's proposed alternative should be authorized i pursuant to 10 CFR 50.55a(a)(3)(ii).
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3.0 CONCLUSION
The INEEL staff has reviewed the information provided by the licensee and concludes that for Requests for Relief IR-005 (Rev.1) and IR-021 (Rev. 3) the addition or deletion of welds does not change the technical content or conclusions of the previous evaluations. - Therefore, it is recommended that relief remain granted pursuant to 10 CFR 50.55e(g)(6)(i). For Requests for Relief IR-028 and IR-029,it is concluded that the Code requirements would result in hardship without a compensating increase in quality and safety, and that the licensee's proposed alternatives will provide reasonable assurance of the operational readiness of the subject systems. Therefore, it is recommended that the licensee's proposed alternatives be authorized pursuant to 10 CFR 50.55a(a)(3)(ii). Request for Relief IR-022 (Rev. 2) was withdrawn by the licensee in the June 28,1996, letter. l 13 1 I
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