NUREG-0989, Safety Evaluation Supporting Proposed Turbine Maint Program. Proposal Satisfies Licensee Commitment Prescribed in Sser 5. Commitment Acceptable Resolution of Turbine Maint Issue

Safety Evaluation Supporting Proposed Turbine Maint Program. Proposal Satisfies Licensee Commitment Prescribed in Sser 5. Commitment Acceptable Resolution of Turbine Maint Issue

ML20237H130
Person / Time
Site:	River Bend
Issue date:	08/26/1987
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20237H115	List: NUREG-0989, Safety Evaluation Supporting Proposed Turbine Maint Program. Proposal Satisfies Licensee Commitment Prescribed in Sser 5. Commitment Acceptable Resolution of Turbine Maint Issue NUREG-1048, Forwards Safety Evaluation Supporting Proposed Turbine Sys Maint Program Submitted w/870513 Ltr
References
RTR-NUREG-0989, RTR-NUREG-1048, RTR-NUREG-989 NUDOCS 8709030130
Download: ML20237H130 (2)

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[p uo u o UNITED STATES

!" NUCLEAR REGULATORY COMMISSION g f,,jg WASHINGTON, D. C. 20555

.....$ SAFETY EVALUATION BY THE OFFICE OF NUCLEAR R,EACTOR REGULATION RELATING TO TURBINE SYSTEM MAINTENANCE PROGRAM GULF STATES UTILITIES COMPANY RIVER BEND STATION, UNIT 1 DOCKET NO. 50-458

1.0 INTRODUCTION

' By letter dated May 13, 1987, Gulf States Utilities Company (the licensee) submitted a proposed turbine system maintenance program for the River Bend Station based on the manufacturer's calculation of missile probabilities.

1 This submittal is a part of the licensee's commitment to resolve the turbine missile issue as described in the Safety Evaluation Report related to the operation of River Bend Station, Supplement No. 5, NUREG-0S89 (November 1985).

2.0 EVALUATION To assure safe turbine operation, the staff requires that the licensee ,

I follow the manufacturer's turbine maintenance program including specific turbine inspection intervals. The turbine inspection intervals should be calculated by an NRC approved method such that the corresponding turbine missile probability is no greater that 10-5 per year for an unfavorably oriented turbine and 10-4 per year for a favorably oriented turbine.

Given the required missile generation probability, the licensee calculated the turbine inspection intervals based on turbine operating conditions and material properties of discs. The licensee reported that the missile generation probability of each low pressure turbine is less that 10-4 per year when each turbine is inspected every six years at River Bend. These values were obtained from a General Electric (GE) analysis which was approved by the staf f (Ref. Safety Evaluation Report related to the Opera-tion of Hope Creek Generating Station, Supplement No. 6, NUREG-1048, July 1986.)

The licensee will follow GE's recommended turbine maintenance program which includes volumetric examination of the low pressure discs, visual and surface examination of the low pressure buckets, and visual examination of accessible surfaces of rotors and discs. The pregram also includes inspection of those valves associated with turbine operation such as turbine stop and control valves, and reheat stop and intercept valves.

The licensee has used acceptable methodology to calculate the turbine missile probability for determination of inspection intervals and has committed to use the manufacturer's recommendations for the turbine maintenance program, 9709030130 870826 PDR ADOCK 05000458 P PDR

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- i 3,0 CONCLUSION ,

I The staff finds that the proposed turbine maintenance program at River Bend satisfies the licensee's commitment prescribed in Supplement 5 of c the River Bend Safety Evaluation Report and it is acceptable. The staff concludes that the above commitment is an acceptable resolution of.the turbine maintenance issue.

j Principle Contributor: J. Tsao l I

Dated: August 26, 1987

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