ML20205C198

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Safety Evaluation Concluding That Proposed Relief Request IR-8,Rev 1,provides Acceptable Alternative to ASME Code Requirements.Recommends Authorization of Proposed Alternative Pursuant to 10CFR50.55a(a)(3)(i)
ML20205C198
Person / Time
Site: Seabrook NextEra Energy icon.png
Issue date: 03/24/1999
From:
NRC (Affiliation Not Assigned)
To:
Shared Package
ML20205C194 List:
References
NUDOCS 9904010107
Download: ML20205C198 (5)


Text

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION FIRST 10-YEAR INTERVAL INSERVIC8! INSPECTION REQUEST FOR RELIEF NORTH ATLANTIC ENERGY SERVICE CORPORATION.

SEABROOK NUCLEAR POWER STATION. UNIT NO.1 DOCKET NO. 50-443

1.0 INTRODUCTION

' inservit a inspection of the American Society of Mechanical Engineers (ASME) Code Class 1, 2, and 3 components shall be performod 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 been granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(i). Title 10 of the Code of Federal Reoulations (10 CFR), Section 50.55a(a)(3) states that altamatives to the requirements of paragraph (g) may be used, when authorized by the NRC, if (i) the proposed altamatives would provide an acceptable level of quality and safety or (ii) compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. Licensee's may choose to complete inservice examinations using subsequent editions of the ASME Code as referenced in 10 CFR 50.55a(b)(2) with limitations on specific editions and addenda. Title 10 of the Code of Federal Reaulations. Section 50.55a(g)(4)(iv) states inservice examination of components and system pressure tests may meet the requirements set forth in subsequent editions and addendas that are incorporated by reference in paragraph (b) of this section, subject to the limitations and modifications listed in paragraph (b) of this section, and subject to Commission approval. Portions of editions or addenda may be used provided that all related requirements of the respective editions or addenda are met.

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)

ENCLOSURE 1

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2-12 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 Seabrook Station is the 1983 edition through Summer 1983 Addenda of Section XI of the ASME B&PV Code.

By letter dated C::tober 30,1998, the licensee requested relief from the code requirements for Seabrook Station.

2.0 liVALUATION 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 the proposed attemative contained in Relief Request No. IR-8, Revision 1 for Seabrook Station. Based on the results of the review, the staff generally adopts the contractor's conclusions and recommendations presented in the Technical Letter Report.

Relief Request No. IR-8 (Revision 1): This request for relief involves the use of the ASME Code,1989 Edition for Examinaton Category B-M-2, item E12.50, Valve Body intemal Surfaces.

Tne ASME Code of record for Seabrook requires a visual examination (VT-3) once each interval of the intamal surfaces of ASME Class 1 valve bodies having nominal pipe size greater than 4 inches. Altematively, the licensee has proposed to use the 1989 Edition of the Code, which only requires item B12.50 be visually examined when the valve is disassembled for maintenance, repair, or volumetric examination. The licensee having considered the related sections of the 1983 and 1989 Editions for Examination Category B-M-2, item B12.50, has committed to implementing the 1989 Edition and allits relevant requirements. Therefore, given that the 1989 Edition is referenced in 10 CFR 50.55a(a)(3)(b)(2), the staff concludes that the use of the ASME Code,1989 Edition will provide reasonable assurance of structural integrity for the item B12.50, valve body intomal surfaces only.

3.0 CONCLUSION

Considering that the portion of the later edition of the code will provide reasonable assurance .

of structural integrity and that the licensee has committed to implementing the requirements of the 1989 Edition for the VT-3 visual examination, the proposed attemative is approved pursuant to 10 CFR 50.55a(g)(4)(iv) for Examination Category B-M-2, item B12.50, valve body intemal surfaces only.

Principal Contributor: G. Hatchett Date: March 24, 1999 l

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  • TECHNICAL LETTER REPORT ON FIRST 10-YEAR INTERVAL INSERVICE INSPECTION BEQMEST_ EOR RELIEF IR-8. REV!SION 1 EQB NORTH ATLANTIC ENERGY SERVICES CORPORATION SEABROOK STATION DOCKET NUMBER: 50-482
1. INTRODUCTION -

By letter dated October 30,1998, the licensee, North Atlantic Energy Services Corporation, submitted Request for Relief IR-8, Rovision 1, seeking relief from the requirements of the ASME Code,Section XI, for the Seabrook Station, first 10-year inservice inspection (ISI) interval. The Idahn National Engineering and Environmental Laboratory (INEEL) staff's evaluation of the subject request for relief is in the following section.

2. EVALUATION The information provided by North Atlantic Energy Services Corporation in support of the request for relief from Code regul ements has been evaluated and the basis for disposition is documented below. The Code of record for the Seabrook Station, first 10-year ISl lnterval, which began March 1990, is the 1983 Edition through Summer 1983 Addenda of Section XI of the ASME Boiler and Pressure Vessel Code.

Reauest for Relief IR-8. Revision 1. Examination Catecoty B-M-2. Item B12.50. Valve Bodv Intemal Sudagg3 Code Reautrement: Examination Category B-M-2, item B12.50, requires 100% VT-3 visual examination of intemal surfaces of valve bodies exceeding 4-inch nominal pipe size (NPS). .

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, ENCIOSURE 2

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'. Licensee's Proposed Altemative: In accorde;nce with 10 CFR 50.55a(a)(3)(i), the licensee proposed to use the 1989 Edition of Section XI for the examination requirements for Examination Category B-M-2, item B12.50. The licensee stated:

" North Atlantic will perform a VT-3 visual examination of Class 1 valves as specified in Table IW.B-2500-1, item B12.50 of the 1989 Edition of the ASME Boiler and Pressure Vessel Code,Section XI when a Class 1 valve is disassembled for maintenance, repair or volumetric examination, utilizing the non-destructive examination methods and criteria of the 1983 Edition of the ASME Boiler and Pressure Vessel Code,Section XI including Addenda through the Summer of 1983."

Licensee's Basis for Prooosed Altemative (as stated):

" Relief is being requested pursuant 1 10 CFR 50.55a(a)(3)(i), on the basis that the proposed attemative will provide an acceptable level of quality and safety. North Atlantic proposes to utilize the 1989 Edition of the ASME Boiler and Pressure Vessel Code,Section XI, Table IWB-2500-1, item B12.50 in lieu of the requirements ,

specified in the 1983 Edition (including Addenda through Summer 1983) of Section XI, Table IWB-2500-1, item B12.50 to perform a visual examinstion (VT-3) of the subject Class 1 valves.

" Compliance with the 1983 Edition of the Code (including Addenda through Summer l 1983) would require the disassembly of six Class 1 valves (one valve within each l group of velves) during each 10-year inspection interval. Disassembly of the subject valves for the sole purpose of performing a visual examination (VT-3) of the intamal surfaces of the valves is not desirable. The general mechanical and structural condition of the subject valves is periodically monitored. The operational readiness ,

l of the subject valves with the exception of RH V 59, RH-V-61, RH V-63 and RH V-65 is verified on a periodic basis by exercising the valves to the open and closed position in accordance with the Seabrook Inservice Test (IST) Program. RH V-59, RH-V-61, RH V-63 and RH-V-65 are manual valves which are normally locked open during plant operation and shutdown periods and do not have an active safety function to change position. Seat leakage integrity of the check valves listed on the attached shee. and motor-operated valves RC-V-22, RC-V-23, RC-V-87, and RC-V-88 are periodically leakage tested due to their reactor coolant pressure isolation function in accordance with Seabrook Station Technical Specification 3.4.6.2.

Additionally, the structural integrity of the subject valves is assured because they are located within the reactor coolant system pressure boundary and bouncary leakage is also required to be monitored during plant operation in accordance with Seabrook Technical Specification 3.4.6.2.

"As identified in 10 CFR 50.55a(b)(2), the NRC has approved the general use of the 1989 Edition of the ASME Boiler and Pressure Vessel Code,Section XI for inservice inspection activities. Examination of the subject valves in accordance with the requirements outlined in the 1989 Edition of Section XI combined with the operational readiness testing, seat leakage testing and on-line reactor coolant boundary leakage monitoring performed by North Atlantic provides an acceptable alternative to the examination requirements imposed for the subject valves by the 1983 Edition (including Addenda through Summer 1983) of Section XI."

Evaluation: The Code of record (83S83) for Seabrook Station requires a VT-3 visual '

- ( rnmination of valve body internal surfaces. As an alternative to the current interval Code requirements, the license has proposed to use the 1989 Edition of the Code for item B12.50 examination requirements. Under the 1989 Code, the VT-3 visual examination is only required when a valve is disassembled for maintenance, repair, or volumetric examination. Since the 1989 Codo has been accepted by the staff and referene ed in 10 CFR 50.55a, the use of these requirements will provide an acceptable level of quality and safety.

' 3. CONCLUSION The INEEL staff evaluated the licensee's submittal and concluded that the licensee's proposed alternative will provide an acceptcble level of quality and safety. Therefore, it is recommended that the proposed alternative be authorized pursuant to 10 CFR 50.55a(a)(3)(i).

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