ML20235X128

Safety Evaluation Supporting Licensee Request to Extend Second 10-yr Inservice Insp & Testing Interval Until 911014

ML20235X128
Person / Time
Site:	Oyster Creek
Issue date:	03/06/1989
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20235X104	List: ML20235X102 ML20235X128
References
NUDOCS 8903130319
Download: ML20235X128 (6)

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. SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REQUEST FOR CLARIFICATION AND UPDATING OF REGULATORY RE0UIREMENTS l

GPU NUCLEAR CORPORATION OYSTER CREEK NUCLEAR GENERATING STATION DOCKET NO. 50-219 INTRODUCTION

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In letter dated May 20, 1988, GPU' Nuclear Corporation (the licensee) requested a change to the ending date for the second ten-year inservice inspection interval i and five changes to update specified inspection requirements to more recent l versions of Section XI of the ASME Boiler and Pressure Vessel Code.  !

EVALUATION l

TWENTY-TWO MONTH EXTENSION OF THE-INSERVICE INSPECTION AND TESTING INTERVAL

1. SCOPE Subsection !WA-2400, " Inspection Intervals," of Section XI of the ASME Code, 1974 Edition, including Summer 1975 Addenda, states that "for plants that are out of service continuously for one year or more, an inspection interval may be extended for an equivalent period." The Dyster Creek Nuclear Generating Station underwent a major refueling and e.aintenance outage of -

twenty-two months during 1983 and 1984 The addition of twenty-two months to the second ten-year interval extends the ending date to October 14, 1991.

In the referenced letter, the-licensee requested that the twenty-two month extension of the inservice inspection interval apply to the inservice test program. Paragraph 50.55a(g)(4)(ii)of10CFRPart50requiresthat the inservice examination'of components and the inservice testing of pumps and. valves conducted during successive 120-month inspection intervals comply with the ASME Code requirements incorporated by reference in para-graph (b) of this section of the regulations 12 months prior to the start of the 120-month interval.

2. CONCLUSION The staff concurs with the licensee that the second ten-year inservice inspection and testing interval is extended by twenty-two months to end October 14, 1991. The inservice inspection and testing programs are conducted to identical Code edition (ASME 1974 Edition, Sumer 1975 Addenda) requirements during identical time interval pursuant to 10 CFR 50.55a(g)(4)(11). l O$C 6 y

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g. RE00EST'l - USE OF INSPECTION DATA COLLECTED ON IGSCC PROGRAM TO SATISFY AUGMENTED ISI PROGRAM REQUIREMENT l 1.. SCOPE In letter dated October 30, 1980, D. M. Crutchfield to I. R. Finfrock stated that the NRC position concerning IWC-1220 exemption criteria of Class 2 welds in the Emergency Core Cooling System, as permitted by_ the 1974 Edition of the ASME_ Code,Section XI, requires that a representative sample of welds in this system be examined during each inspection interval.

Further,'the safety related system could not be completely exempt from examination based upon the requirements of 10 CFR Part 50 Appendix A, General Design Criteria 36 and 39, and the Summer 1978 Addenda to the 1977 Edition of Section XI.

In letter, I. R. Finfrock to D. M. Crutchfield dated February 5,1981, and again'in letter, P. B. Fielder (GPUN) to D. M. Crutchfield dated July 2,1982, GPUN committed to perform volumetric examinations of Isolation Condenser Piping greater than 4" Nominal Pipe Sire (NPS). Specifically,'an Augmented Inspection Program to inspect 29 welds in the Isolation Condenser System was implemented. Presently,10 of the 29 have been inspected under this program.

GPUN has replaced the Augmented Inspection Program with the IGSCC Inspection Program. Over 200 weld inspections in the Isolation Condenser System have been performed during the previous two refueling outages (10R and IIR) under the IGSCC Inspection Program. Approximately 33 weld inspections for IGSCC in the Isolation Condenser System have been tentatively scheduled for refueling outage 12R. These inspections performed on the Isolation Condenser System under the IGSCC Inspection Program far exceed the original Augmented Inspection Program.

The purpose of inservice inspection of piping is to provide continued assurance that the structural integrity and reliability of the piping-is maintained and that there continues to be an extremely low probability of abnormal leakage (10 CFR 50 Appendix A, Criterion 14). Piping with weldments that are susceptible to degradation rechanists recuire more frequent inspections to provide such continued assurance. Weldsents in BWRs will have different degrees of susceptibility to IGSCC depending on the material and proces:ing involved. Therefore, the inspection frequencies recommended for IGSCC inspections are based on the condition of each weldment.

The extent of inspection recommended depends on the number of cracked welds in the plant as well as the condition of each individual weldment. In addition, welds that have already been found to be cracked will have '

varying degrees of susceptibility to further cracking, depending on the remedial actions taken.

In as much as the piping welds examined in one program and re-examined by the same procedure to the reovirements of the second program is duplication of effort, the licensee requests that inspections perforracd and date collected for the IGSCC Program be utilized to fulfill the requiretrerts cf the Augmented ISI Program.

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v 2. CONCLUSION The staff concludes that the inspection data collected to satisfy the IGSCC Program requirements may be used to satisfy the requirements of the Augmented ISI Program.

PEOUEST 2 - USE OF INSPECTION DATA COLLECTED Oh ICSCC PROGFAli TO SATISFY ISI MUURAM REQUIREMENTS

1. SCOPE In their Inservice Inspection Program, the licensee performs volumetric examination of the full weld thickness for Category B-J welds in accordance with ASME Section XI Code,1978 Edition, Sumer 1975 Addenda. Standards for evaluation are in accordance with ASME Section XI Code,1977 Edition, Summer 1978 Addenda.

In their Augmented IGSCC Procram, the licensee performs ultrasonic examin-ation of the bottom one-third of the welds and surface liquid penetrant examination of stainless steel welds in the systems susceptible to IGSCC (Core Spray, Reactor Recirculation, Shutdown Cooling, Isolation Condenser, and Cleanup Demineralized Systems).

As a result of satisfying the examination requirements of both Programs, some Category B-J welds have been examined twice during the same outage.

Therefore, the licensee requests that the examinations performed and data collected to satisfy the IGSCC Program requirements be utilized to satisfy the ISI Program requirements.

2. CONCLUSION The staff concludes that the inspection data collected to satisfy the IGSCC Program requirements may be used to satisfy the requirements of the ISI Program.

REQUEST 3 - UPDATE OF ASME CODE EXAf11 NATION REQUIREMENT FOR CATEGORY B-A AND B-D REAc10R PRES 5URE VE5SEL WELD 5

1. SCOPE The Inservice Inspection Program of the Oyster Creek Nuclear Generating Station is conducted to the requirements of the ASME Boiler and Pressure Yessel Code,Section XI,1974 Edition, Sumer 1975 Addenda, and updated to the 1977 Edition, Sumer 1978 Addenda for Article IWB-3000, " Acceptance

. Standards for Flaw Indications."

l The extent of the examination and inspection volume determined by the full base metal thickness (t) requirement as delineated in Section XI 1974 I Edition, Sumer 1975 Addenda, from Table IWB-2500 for all reactor vessel welds, inclusive, that are identified as Categories B-A, B-B, B-C, and B-D is not consistent with the extent of the examination and inspection volume l determined by the half thickness (it) requirement for the weld acceptance evaluations as delineated in Section XI,1977 Edition, Sumer 1978 Addenda Ngb!khb0 * "" "' ** ** "

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t The licensee requested that the examination and inspection requirements that determine the v vumetric extent of reactor pressure vessel welds be updated to the ASME Boiler and Pressure Vessel Code,Section XI,1977 Edition, Sun,er 1978 Addenda, Subsection IWB-2500 for Categories B-A and B-D welds. Reactor vessel weld inspecticn performed in accordance with the 1977 Edition including Sumer 1978 Addenda permit the use of it distar.ce from the weld ir determining the volumetric extent of examination. The licensee states that weld inspection to the it extent would minimize the radiation exposure acquired during insulation removal, weld surface preparation, and inspection stay time. The radiation exposure would be substantially reduced without a commensurate decrease in the quality of the weld examination and inspection.

2. CONCLUSION The staff agrees with the licensee that the extent of volumetric examination of Category B-A_ and B-D welds in the reactor pressure vessel may be per-formed to the requirements of Section XI, ASME Boiler and Pressure Vessel Code,1977 Edition, Sumer 1978 Addenda, in lieu of the extent required by Section XI, ASME Boiler and Pressure Vessel Code,1974 Edition, Sumer 1975 Addenda. The procedures, methods and requirements, other than the extent of volumetric examination (it vs t), of Section XI,1974 Edition, Sumer 1975 Addenda, will continue to be performed in the examination of Category B-A.

and B-D welds in the reactor pressure vessel at the Oyster Creek Nuclear Generating Station.

REQUEST 4 - UPDATE OF ASME CODE ARTICLE IWA-4000 AND ARTICLE IWA-7000 FROM 1974 EDITION SUMMER 1975 ADDENDA TO 1983 EDITION SUMMER 1983 ADDENDA

1. SCOPE In their letter dated May 20, 1988, the licensee requested an update for  !

Article IWA-4000, " Repair Procedures," and Article IWA-7000, " Replacements,"

from Section XI ASME Code,1974 Edition including Sumer 1975 Addenda, to Section XI ASME Code,1983 Edition including Sumer 1983 Addenda. The reason the update was requested is that the latter ASME Code edition was clearer and more explicit in these particular areas than the former edition.

For example, Article IWA-7000, " Replacements," is not addressed in the Section XI, 1974 Edition. ,

2. CONCLUSION The staff concludes that the comitment by the licensee for Section XI, Article IWA-4000 and Article IWA-7000, may be updated from the ASME Code, 1974 Edition including Sumer 1975 Addenda to the 1983 Edition including Sumer 1983 Addenda.

., RE00EST 5 -REQUEST TO USE SECTION XI SUBSUBARTICLE IWB-3640 ASME CODE 1986 EDITION FOR INSERVICF INSPECTI0f. AhC IGSCC Ih5FECTI0fi PRCGRAM5

1. SCOPE The licensee is committed to Section XI ASME Code, 1977 Edition, Summer 1978 Addenda,-for Subparagraph IWB-3514.3, " Allowable Indication Standards for Austenitic Piping." Subsubarticle IWB-3640, " Evaluation Procedures and Acceptance Criteria for Austenitic Piping,". provides analytical methods for flaw evaluation exceeding the allowable limit of Subparagraph IWB-3514.3.

NUREG 0313, Revision 2, " Technical Report on Materials Selection and Pro-cessing Guidelines for BWR Coolant Pressure Boundary Piping," endorsed the methods and criteria described in IFB-3640 of the ASME Code, 1986 Edition, for IGSCC flaw evaluation. In addition, Generic Letter 88-01, "NRC Position on IGSCC in BWR Austenitic Stainless Steel Piping," recommended that methods and criteria of Subarticle IWB-3600 of Section XI of the ASME Boiler and Pressure Vessel Coe,1986 Edition, be used for crack evaluation and repair.

The licensee requested that the methods and criteria of IVE-3640, ASPE Boiler and Pressure Vessel Code,1986 Edition, be used for crack evaluation and repair in the Inservice Inspection and IGSCC Inspection Programs.

2. CONCLUSION The staff concludes that the methods and criteria of Subsubarticle IWB-3640,Section XI, ASME Boiler and Pressure Vessel Code, 1986 Edition, may be used by the licensee for crack evaluation and repair in the Inservice Inspection and IGSCC Inspection Programs.

CONCLUSION y We conclude'from our evaluation that the requests for clarification and updating of regulatory requirements made by the GPU Nuclear Corporation in letter dated May PO,1988, are acceptable for inclusion in the inspection programs at the Oyster Creek Nuclear Generating Station. We conclude the following:

1. The end of the second ten-year Inservice Inspection and Testing Interval is extended by twenty-two months to October 14, 1991.

2. Pursuant to 10 CFR 50.55a(g)(4)(ii), the Inservice Inspection Program and the Inservice Testing Program should be conducted to identical ASME Boiler and Pressure Vessel Code edition requirements.

3. The inspection data obtained to satisfy the requirements of the IGSCC Program may be used to satisfy the requirements of the Augmented Inservice Inspection Program.

4 The inspection data obtained to satisfy the requirements of the IGSCC Program may be used to satisfy the requirements of the Inservice Inspection Program.

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l S. The extent of volumetric examination of Category B-A and B-D welds in the reactor pressure vessel may be performed to the requirements of Section XI, )

ASME Boiler and Pressure Vessel Code,1977 Edition, Sumer 1978 Addenda, '

instead of to the requirements of Section XI, ASME Boiler and Pressure Yessel Code,1974 Edition, Sumer 1975 Addenda. l

6. Articles IWA-4000 and IWA-7000 may be updated by the licensee from Section I XI, ASME Boiler and Pressure Vessel Code,1974 Edition, Sumer 1975 Addenda )

to Section XI, ASME Boiler and Pressure Vessel Code,1983 Edition, Sumer i 1983 Addenda.

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7. The methods and criteria of Subsubarticle IWB-3640, ASME Boiler and Pressure Vessel Code,1986 Edition, may be used by the licensee for crack evaluation and repair in the Inservice Inspection Program and the IGSCC Inspection Prograni.

Based on the above, we have determined that certain ASPE Boiler and Pressure  !

Vessel Code requirements may be updated to later Comission approved Code editions, pursuant to 10 CFR 50.55a(g). In addition, we have clarified procedures and inspection requirements for the Oyster Creek Nuclear Generating Station. The updating of the inspection program and the clarification of regulatory requirements is authorized by law, will not endanger life or property or the comon defense and security, and is otherwise in the public interest.

Dated: March 6, 1989 Principal Contributor: F. Litton l

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