ML20198B380

SER Accepting one-time Request for Relief from Certain Provisions of Section XI of ASME Boiler & Pressure Vessel Code,Per 10CFR50.55a for Certain Plant Safety/Relief Valves

ML20198B380
Person / Time
Site:	LaSalle
Issue date:	12/14/1998
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML20198B377	List: ML20198B374 ML20198B380
References
NUDOCS 9812180155
Download: ML20198B380 (3)

Text

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g pnarg\ . UNITED STATES  !

2* ] NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 30086 0001 I

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION

• RELATED TO THE INSERVICE TESTING PROGRAM RELIEF REQUESI COMMONWEALTH EDISON COMPANY LASALLE COUNTY STATION. UNIT 1 DOCKET NO. 50-373

1.0 INTRODUCTION

The Code of Federal Reaulations,10 CFR 50.55a, requires that inservice testing (IST) of certain American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Code) Class 1,2, and 3 pumps and valves be performed in accordance with Section XI of the

. ASME Code and applicable addenda, except where relief has been requested and granted, or proposed attematives have been authorized by the Commission, pursuant to 10 CFR 50.55a(a)(3)(i), (a)(3)(ii), or (f)(6)(i). In order to obtain relief or an authorized attemative, the applicant must demonstrate that : (1) conformance is impractical for its facility; (2) the proposed attemative provides an acceptable level of quality and safety; or (3) compliance would result in a hardship or unusual difficulty without a compensating increase in the level of quality and safi 'y.

2.0 BACKGROUND

By letter dated October 8,1998, Commonwealth Edison Company (CcmEd, the licensee) submitted a one-time reques+ for relief from certain ASME Code IST requirements pertaining to the frequency of testing of several main steamline safety relief valves for LaSalle, Unit 1. The i plant IST program requires that the testing meet the requirements of the 1989 Edition of I Section X! of the ASME Code, which requires overpressure and rulief devices to be tested in accordance with ASME/ ANSI OM-1-1987. Specifically, the request seeks a one-time relief from 1 . performing the next periodic tests before the dates which would be required by OM-1. The I

following is a list of the safety relief valves for which the licensee is seeking this relief:

i

VALVE ID CLASS GAL DESCRIPTION 4 1821-F013A 1 B/C Main Steamline Safety Relief Valve

1821-F0138 1 B/C Main Steamline Safety Relief Valve

1821-F013C 1 B/C Main Steamline Safety Relief Valve

1B21-F013D 1 B/C Main Steamline Safety Relief Valve

[ 1821-F013E 1 B/C Main Steamline Safety Relief Valve 1921-F013F 1 B/C Main Stea ,line Safety Relief Valve 1821-F013G 1 B/C Main SteamEne Safety Relief Valve

'iC21-F013H 1 B/C Main Steamline Safety Relief Valve 1821-F013J 1 B/C Main Steamline Safety Relief Valve 1921-F013K 1 B/C Main Steamline Safety Relief Valve 9812180155 991214 ENCLOSURE PDR ADOCK 05000373 P PDR

l l

i 1821-F013L 1 B/C Main Steamline Safety Relief Vsbe 1821-F013M 1 B/C Main Steamline Safety Relief Vaive l 1B21-F013N 1 B/C Main Steamline Safety Relief Valve 1821-F013P 1 B/C Main Steamline Safety Relief Valve 1B21-F013R 1 B/C Main Steamline Safety Relief Valve ,

1821-F013S 1 B/C Main Steamline Safety Relief Valve l 1821-F013U 1 B/C Main Steamline Safety Relief Valve 1B21-F013V 1 B/C Main Steamline Safety Relief Valve For the above described valves, the licensee is requesting one-time relief from the following testing requirements:

1 OM-1, Section 1.3.3.1(b) - All valves of each type and manufacturer shall be tested .

within each subsequent 5 year period with a minimum of 20% of the valves tested within any 24 months.

3.0 BASIS FOR RELIEF The main steam safety / relief valves at LaSalle are all of the same type and manufacturer and are grouped together per the requirements of OM-1-1987. Main steam safety / relief valves l 1821-F013A, C, E, G, H, M, U, and V are required to be tested by March of 2001 since these valves were last tested in March 1996. All other Main Steam safety / relief valves were last tested December 12,1997. OM-1 requires that a minimum of 20 percent of the valves of each type and manufacturer be tested within any 24 month period. To comply with the OM-1 24 month frequency, Comed must test at least four main steam safety / relief valves prior to December 12,1999. Due to an extended maintenara outage from September 1996 until August 1998, the next LaSalle refueling outage has been delayed until January 8,2000.

Comed has scheduled one planned outage prior to the next refueling outage with a duration of 6 days.

The licensee is requesting relief from the above OM-1 test frequency requirements stating that the tests would result in hardship without a cornpensating increase in quality or safety. The licensee states that the removal and replacement of the valves for testing prior to the next refueling outage would require an estimated 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> per valve. A related OM-1 requirement states that when a partial complement of pretested valves is installed, all valves removed must be tested prior to plant startup. This would add an additional 4 to 5 days of critical path time to the outage. In addition, removal and replacement of the safety / relief valves would result in exposures of approximately 1.0 to 1.2 man-rem per valve. The licensee states that extending the planned outage, or requiring an additional unit shutdown prior to the next refueling outage to perform the required testing would result in a hardship to Comed.

The licensee proposes that the four LaSalle, Unit 1, main steem safety / relief valves deferred will be tested and replaced with pretested valves during the up;oming refueling outage (L1RO8).

This would require a one-time scheduler relief from the 24-month test interval by extending the interval to 26 months.

l 4.0 EVALUATION The staff finds that performing the ma!n steam safety / relief valve testing to meet the above ,

scheduler requirements of OM-1 would result in unusual hardship without a compensating I increase in the level of quality and safety. The proposed two-month period of time, beyond the l i

l dates these valves would be required to be tested to meet OM-1 until the next refueling outage  !

in January 2000, is relatively short. The licensee has stated that the as-found safety / relief valve set pressure testing has been very consistent for the last fivo years and there were no test failures in the last three years. Based on a review of the licensee's operating experience with these valves, significant additional degradation of these components would not be expected

! during the additional two months requested and, thus, there is reasonable assurance of valve l operability for the period requested. Therefore, the staff finds that it is acceptable to perform l the testing of these valves, as proposed by the licensee, during the next Unit i refueling l outage. l

5.0 CONCLUSION

Based on the above evaluation, the staff concludes, pursuant to 10 CFR 50.55a(a)(3)(ii), that the licensee's proposed attemative to the above discussed ASME Code testing requirements may be authorized for the two-month period requested on the basis that compliance with these

! requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.

l Principle Contributor: G. Hammer, NRR/DE i D. Sksy Date: December 14, 1998 i

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