ML20236X649

Safety Evaluation Accepting 871006 Request for Reduced Duration Integrated Leak Rate Test at Facility,Based on Methodology in BN-TOP-1,Rev 1, Testing Criteria for Integrated Leak Rate Testing of Primary Containment..

ML20236X649
Person / Time
Site:	Waterford
Issue date:	12/01/1987
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20236X590	List: ML20236X589 ML20236X649
References
NUDOCS 8712090365
Download: ML20236X649 (2)

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\ . . . . . J' SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION CONTAINMENT INTEGRATED LEAK RATE TEST DURATION LOUISIANA POWER AND LIGHT COMPANY WATERFORD STEAM ELECTRIC STATION, UNIT 3 DOCKET NO. 50-382

1.0 INTRODUCTION

By letter dated October 6, 1987, Louisiana Power and Light Company (LP&L, the licensee) requested approval of their proposal to use a reduced duration (i.e., less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> retained pressure) containment integrated leak rate test (ILRT) at their Waterford Steam Electric Station, Unit 3 during their upcoming second refueling outage and in the future.

2.0 DISCUSSION 10 CFR 50.54(o) requires all plants to conduct ILRTs in accordance with Appendix J to 10 CFR 50. The Waterford 3 Technical Specifications and 10 CFR 50 Appendix J direct that Type A leak rate testing be conducted using the methods and provisions of ANSI N45.4-1972, " Leakage Rate Testing of Structures for Nuclear Reactors". Both ANSI N45.4-1972 and the Waterford 3 FSAR (Section 6.2.6.1) specify a test period of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of retained internal pressure with the following qualification:

If it can be demonstrated to the satisfaction of those responsible for the acceptance of the containment struc-ture that the leakage rate can be accurately determined during a shorter test period, the agreed-upon shorter period may be used.

3.0 EVALUATION In support of reduced duration ILRTs the Bechtel Corporation submitted the topical report BN-TOP-1, Revision 1, " Testing Criteria for Integrated Leak Rate Testing of Primary Containment Structures for Nuclear Power Plants". The report established criteria for the test duration based, in part, on (1) stabilization or decline of the leak rate with time, (2) the final observed upper bound 95% confidence limit being less than 75% of the allowable leak rate, and (3) a minimum test duration of six hours.

In a safety evaluation report dated January 15, 1983, the NRC concluded that the testing criteria in BN-TOP-1, Revision 1 met the requirements of 10 CFR 50 Appendix J and ANSI 45.4-1972, and were acceptable for referencing by licensees.

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. LP&L proposes to adopt; the methodology- described in BN-TOP-1 for the

j. 'second refueling. outage and subsequent ILRTs.

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4.0 CONCLUSION

Because LP&L proposes to employ methodology. described in' a previously

~ - (/ approved ~ topical report,: 1.e. , BN-TOP-1, Revision 1 the staff concludes

.that use of-a reduced duration ILRT at Waterford 3 during.the'second-refueling' and in.thetfuture,- is acceptable.

Principal Contributor: J. Wilson L/J Dated: December l' 1987- ,

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