ML18094B323

Provides Addl Info to Assist NRC in Reviewing License Change Request 87-15 Re Reduction of Turbine Valve Test Frequency, Per Guidance in WCAP-11525

ML18094B323
Person / Time
Site:	Salem
Issue date:	02/26/1990
From:	Labruna S Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NLR-N89219, NUDOCS 9003090029
Download: ML18094B323 (3)

Text

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• Public Service Electric and Gas Company Stanley LaBruna Public Service Electric and Gas Company P.O. Box 236, Hancocks Bridge, NJ 08038 609-339-4800 Vice President - Nuclear Operations FEB 2 6 1990 NLR-N89219 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Gentlemen:

TURBINE VALVE TEST FREQUENCY ADDITIONAL INFORMATION SALEM UNIT NOS. 1 AND 2 DOCKET NOS. 50-272 AND 50-311 The purpose of this letter is to provide additional information to aid your review of our License Change Request (LCR) 87-15, forwarded via PSE&G letter NLR-N87192 dated December 24, 1987~

That LCR requested modification of the turbine valve test frequency in accordance with the guidance provided in WCAP-11525, "Probabilistic Evaluation of Reduction in Turbine Valve Test Frequency." The enclosed additional information supplements the previously submitted information and is similar to that supplied in support of the NRC review of the Prairie Island submittal on this subject.

Turbine Valve History (January. 1984 through September. 1989)

The turbine valves installed at Salem 2 are tested for proper operation (close on demand) on a weekly basis pursuant to the Technical Specifications. The Unit 2 valves were tested 119 times during the period reviewed. The Unit 1 valves, although not subject to a Technical Specification requirement, were tested 103 times during the referenced period.

Also during that period, there were no instances of unplanned turbine design overspeed (>120% of design operating speed) and no single turbine valve failures that could have led to a turbine overspeed condition.

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Document Control Desk 2

• FEB 2 6 rggo NLR-N89219 Additional Discussions of Safety Impacts of Reduced Frequency Testing A test of the turbine valves at the Salem plant requires that the unit power be reduced to between 85 and 90% of full power. This weekly reduction in power causes a number of system challenges and events which are undesirable:

a. Reducing power is typically accomplished by the addition of boron to the Reactor Coolant System (RCS) with control rods being used primarily for Delta I control. Upon return to full power, the added boron must be removed from the RCS.

This results in a substantial amount of water which must be processed by plant systems and in the generation of radioactive waste in the form of resins used to remove the excess boron.

b. The Salem units were designed primarily for base load operation. Load following and load reduction increase the probability of equipment malfunctions which may lead to reactor trips. Load reductions also result in additional wear and stress on components.

Role of WCAP-11525 in this License Change Request WCAP-11525 serves as the manufacturer's recommendation for turbine valve testing for the plants represented in the Westinghouse Owners Group Turbine Valve Testing Frequency subgroup. This analysis recommends a test interval of up to, but not exceeding, one year for both Salem units.

Supplementary Plant Specific Information The total turbine missle ge~5rat!~n probability for each of the Salem units is less than 10 yr

• PSE&G will share all available turbine valve failure information with Westinghouse Corporation, the manufacturer, in support of their turbine valve component failure data base.

PSE&G will establish and maintain, in an auditable manner, valve failure rate information to be reviewed at least once every three years and updated when more than minor changes occur in the data.

The turbine valve testing frequency probabilistic analysis (by the methodology of WCAP-11525) will be reevaluated when any major changes to the turbine system are made in accordance with 10 CFR 50.59 or when a significant upward trend in the valve failure rate data is identified.

Document control Desk 3

• FEB 2 6 (990 NLR-N89219 Based on the above plant specific information and the analysis and recommendations in WCAP-11525, PSE&G believes that reduced turbine valve test frequencies would enhance the safety and reliability of the Salem plants. Reducing the fre.quency would subject critical plant systems to less wear and tear, reduce the quantity of radwaste to be processed and enhance operational safety.

Should you have any questions, please feel free to contact us.

Sincerely, c Mr. J. c. Stone Licensing Project Manager Mr. T. Johnson Senior Resident Inspector Mr. w. T. Russell, Administrator Region I Mr. Kent Tosch, Chief New Jersey Department of Environmental Protection Division of Environmental Quality Bureau of Nuclear Engineering CN 415 Trenton, NJ 08625