ML20057A379

SE Concluding That Second 10-yr Interval Inservice Insp Program Plan for Plant Has Unacceptable Exam Sample as Discussed in Encl Inel TER

ML20057A379
Person / Time
Site:	Davis Besse
Issue date:	08/20/1993
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20057A376	List: ML20057A375 ML20057A379
References
NUDOCS 9309140115
Download: ML20057A379 (6)

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! NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 2055M001 Enclosure 1 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION I 0F THE i SECOND TEN-YEAR INTERVAL INSERVICE INSPECTION PROGRAM PLAN  :

fDB TOLEDO EDISON COMPANY DAVIS-BESSE NUCLEAR POWER STATION. UNIT 1 l DOCKET NO. 50-346

1.0 INTRODUCTION

l Technical Specification 4.0.5 for Davis-Besse Nuclear Power Station, Unit 1, states that inservice inspection and testing 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 ,

code and applicable Addenda as required by 10 CFR 50.55a(g), except where '

specific written relief has been granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(i). Part 50.55a(a)(3) of 10 CFR 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 r hardship or unusual difficulties without a compensating increase in the level of quality and safety. l l 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 preservice examination requirements, set forth in the ASME Code,Section XI, Rules for Inservice Inspection of fluclear 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 each ten-year interval 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) on the date twelve months grior to the start of l the 120-month inspection interval, subject to the limitations and modifications listed therein. The components (including supports) may meet the requirements set forth in subsequent editions and addenda of the ASME Code incorporated by reference'in 10 CFR 50.55a(b) subject to the limitations and modifications listed therein.

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 i practical for its facility, information shall be submitted to the Commission j in support of that determination and a request made for relief from the ASME 1 Code requirement. After evaluation of the determination, pursuant to 10 CFR 50.55a(g)(6)(i), the Commission may grant relief and may impose alternative requirements that are determined to be authorized by law, will not i endanger life, property, or the common defense and security, and are otherwise - '

i in the public interest, giving due consideration to the burden upon the licensee that could result if the requirements were imposed. i l

9309140115 930820 PDR P

ADOCK 05000346 PDR i

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Toledo Edison Company (the licensee) has prepared the Second Ten-Year Interval Inservice Inspection (ISI) Program Plan for Davis-Besse Nuclear Power Station, Unit 1, Revision 3, to meet the requirements of the 1986 Edition of Section XI of the ASME Boiler and Pressure Vessel Code, with the following exception.

The selection criteria for Code Class I piping welds has been determined by the 1974 Edition, through Summer 1975 Addenda, as permitted by 10 CFR 50.55a(b). The NRC staff, with technical assistance from its contractor, the Idaho National Engineering Laboratory (INEL), has evaluated the Second Ten-Year Interval Inservice Inspection Program Plan for Davis-Besse Nuclear Power Station, Unit 1, Revision 3, additional information related to the Program Plan, and the requests for relief from certain ASME Code requirements determined to be impractical for Davis-Besse, Unit 1, during the  !

second inspection interval.

2.0 EVALUATION The ISI Program Plan has been evaluated for (a) application of the correct Section XI Code edition and addenda, (b) compliance with examination and test ,

requirements of Section XI, (c) acceptability of the examination sample,  ;

(d) compliance with prior ISI commitments made by the licensee, (e) correctness of the application of system or component examination exclusion criteria, and (f) adequate information in support of requests for relief from certain Section XI Code requirements deemed impractical by the licensee. However, the NRC staff will make a final determination on the licensee's ISI Program Plan following the meeting with the licensee on September 23, 1993.

In Revision 3 of the Second Ten-Year Intarval Inservice Inspection Program Plan for Davis-Besse Nuclear Power Station, Unit 1, and in Request for Relief RR-B4, the licensee recognized that significant portions of the Main Steam, Main Feedwater, Auxiliary Feedwater, High Pressure injection, Decay Heat, and Containment Spray Systems were being excluded from ISI examinations based on  !

wall thickness criterion contained in Examination Categories C-F-1 and C-F-2.

Consequently, the licensee expanded the 7.5% examination sample to include all nonexempt welds. However, the welds selected that had a nominal wall thickness less than the minimum requirements of Examination Categories C-F-1 '

and C-F-2 were scheduled to receive a surface examination only. As a result, Revision 3 of the licensee's ISI Program for Class 2 piping welds showed a significant reduction (60%) in the total number of volumetric examinations being performed during the second 10-year inspection interval.

In addition to fewer volumetric examinations being performed on the subject Class 2 piping systems during the second 10-year interval, the licensee has also significantly reduced (55%) the number of Examination Category C-C component supports being examined. This reduction is based on Examination Category C-C requirements that state that examinations for component supports 1 are limited to attachments of those components requ' ed to be examined under i Examination Categories C-F and C-G (i.e., wall thickness 13/8 inch). l l

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~ l The purpose of an ISI program is to determine if unanticipated system degradation is occurring due to phenomena such as erosion, corrosion, or cracking. These phenomena would normally occur at the ID surface of the piping system and would not be expected to be detected during the performance of OD surface examinations. The NRC staff talieves that in order to determine whether unanticipated inservice degradation is occurring, the substituted

" thin wall" welds should receive a volumetric examination, and that the Examination Category C-C component supports associated with these " thin wall" welds should also receive ISI examinations.

The information provided by the licensee in support of requests for relief has been evaluated and documented in the attached INEL Technical Evaluation Report (TER). The NRC staff concurs with the findings and recomendations contained in the TER. Table 1 presents a sumary of the relief requests and the status of each as determined by the staff.

3.0 CONCLUSION

l The NRC staff concludes that the Second Ten-Year Interval Inservice Inspection Program Plan for Davis-Besse Nuclear Power Station, Unit 1, Revision 3, has an unacceptable examination sample, as discussed above and in Sections 2.2.2 and 3.2.2.1 of the INEL Technical Evaluation Report.

In order for the NRC staff to find the Program Plan acceptable and in accordance with the full requirements of 10 CFR Part 50.55a(g)(4) and ,

Technical Specification 4.0.5, the licensee should address the following issues at the meeting of September 23, 1993: (1) Volumetric examinations in lieu of surface examinations of the substituted Examination Category C-F-1 and C-F-2 " thin wall" welds as currently specified in Revision 3 of the Program Plan, and (2) Examination Category C-C ISI examinations of the component supports associated with the " thin wall" welds.

Furthermore, the NRC staff concludes that relief from the Code requirements for Request for Relief Nos. RR-A1, RR-A2, RR-A3 (partial), RR-A6 and RR-A7 (with conditions), RR-B1, RR-B2, RR-B3 (with conditions), and RR-B5 may be granted. Alternative examinations that are authorized are Request Nos. RR-A4 (with conditions) RR-A5, and RR-A7, RR-A9, RR-B3, and RR-Cl (with conditions).

Request for Relief No. RR-84 is denied, and Requests for Relief Nos. RR-A8 and RR-B6 are not required.

The NRC staff has determined that granting relief, pursuant to 10 CFR 50.55a(a)(3)(1), (a)(3)(ii), and (g)(6)(1), is authorized by law and will not endanger life or property, or the common defense and security and is otherwise in the public interest. In making this determination, the NRC staff has considered the alternate testing being implemented, compliance resulting in a hardship without a compensating increase in safety, and the impracticality of performing the required testing considering the burden if the requirements i were imposed. i i

Principal Contributor: T. McLellan Date: August 20, 1993

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PNCWSURE 2 DAVIS-BESSE NUCLEAR POWER STATION, UNIT 1 Page 1 of 3 Second 10-Year ISI Interval TABLE 1

SUMMARY

OF RELIEF REQUESTS i

- Relief Relief Regsest System or Exam I t rei WerNired Werpest pueber Component Category No. Votime or Area to be Examined Method Licensee receosed Alternative Status RR Al Reactor F-F B5.10 Nortte safe-end Welds: Surface and 100% volunetric examination, Granted Cootent System WR-53 v, WR 53-W votumetric from ID surface (in lieu of BJ 89.10 Nottle-to pipe Welds: 0D surface examination)

FW1114, FW113A, FW56A, FW1118, FW1138, FW568 RR A2 Reactor B-A B1.40 RPV head-to flange Weld: WM 7 surface and None. Votimetric examination Granted Pressure volumetric to max. extent practical and Vesset a 100% surface examination 1

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RR A3 Decay Heat B-P B15.50 Decay heat valve pit lines: VT-2 visual Wone. Visual examination of Granted 1 Valve Pit 3/4" , B" , and 12"-CCA-4 during floor through pit inspection for system IWB 5200 port - (located et the pressure opposite end of the valve pit

, system tests i pressure from the concerned piping) l tests Denied for l system

, hydro ,

i tests RR A4 Class 1 IWA-5250 Class 1 pressure retaining botting VT-3 visual None. VT-3 visual of only Authorized

! Botting at tesking comections (att botting effected botting with I removed) conditiens in TER RR A5 Reactor B-D B3.90 RPV notate-to-shett welds and Volumetric Deferrat of all nozzle Authorized Pressure B3.100 nozzle inner radit: (t 25% 5 50% examinations until test vessel (Z Axis) WR 13/14/72-Z of nortles inspecd on period of interval (x Axis) WR 13/14/72 X during ist ,

period)

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DAVIS-BESSE NUCLEAR F0WER STATION, UNIT 1 Page 2 of 3 Second 10-Year ISI Interval TABLE 1

SUMMARY

OF RELIEF REQUESTS Retief Relief Reepest System or Exam Itum Rapsired Rerpar st Iksuber Compnnmt Category No. Voltme or Area to te Exiuminnf Method Licmtee Proposed Alternative Status RR-A6 Reactor 8-L-2 812.20 Reactor coolant ptep caaing VT-3 visual vi-3 visual only if the pu m Granted Coolant Pwes internal surfaces is disassenbted for with maintenance conditions in TER RR-A7 Class 1 Botted IWA-5242 Class 1 pressure retaining botting vi-2 visual Austenitic materlats none Authorized Connections at insulated bolted connections (insulation with removed) Carbon steel - insulation conditions removed once per period in TER RR A8 Reactor B L-1 812.10 Reactor coolant pw p casing welds Voltmetric Use of Code Case N 481 Relief not Coolani Ptsps examination required RR-A9 Component IWF Class 1, 2, and 3 Conponent Select Use of Code Case N-491 Authorized Supports Supports supports of wIth corponents conditions required in TER under IWB, IWC, and IWD RR-81 DNR Heat CA C1.10 DNR Meat Exchanger E27-1 and E27-2 vatteetric None. Voltmetric examination Granted Exchanger Shett-to-flange velds examination to maximtn extent practical RR-82 Core Flood C-M C7.40 Train 1: Hydro test None. System inservice test Granted System from MOV CF-1B to CF 29 and CF-27 per per IWA 5211(a)

Train 2: IWC 5222 from MOV CF-14 to CF 28 and CF-26 '

RR 93 Class 2 IWA-5250 Class 2 pressure retaining botting vi 3 visual None. vi-3 visual of only Authorized Botting at teeking connections (att botting effected botting with removed) eonditions in TER 4

l RR B4 ECC and MS C F-1 " Thin wall" piping welds in the ECC vottnetric Surface examination of the Denied

Systems C-F-2 and M5 systems examination substituted " thin watt" welds l

DAVIS-BESSE NUCLEAR POWER STATION, UNIT I Page 3 of 3 Second 10-Year ISI Interval TABLE 1

SUMMARY

OF RELIEF REQUESTS Relief Relief Reepsest . System or Exam Itew ReepJiral Rerpsest Ntsuber Compnnent Category No. Voltane or Area to be Examined Method Licemee Prtposed Alternative Status RR-B5 Containment CH C7.30 Contairvnent purge lines VT-2 visual None. VT-2 visuet (soap Granted Purge System CT.40 from CV5005 to CV5006, and per bubble) during pneunatic test f rom CV5007 to CV5008 IWC-2510(b) to maxinn extent practicat and Appendix J teak rate test RR-86 Emergency Step C-ti C7.30 Emergency stnp recirculation lines VT-2 visual None. Guerchipe enclosure Relief is Recirculation C7.40 and Valves DH9A and DH98 enclosed during drains will be examined for not C7.70 by guardpipe (Decay Heat Trains 1 system leakage requiref C7.80 and 2) pressure tests RR C1 Class 3 lWA-5250 Class 3 pressure retaining botting VT 3 visual None. VT-3 visual of only Authorized Botting at teaking connections (att bolting effected botting with removed) conditions in TER l

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