ML20198C125

Discusses 850522 Proposed Tech Spec Changes to Surveillance Requirement 4.8.1.1.2 Re Electrical Power Sys.Proposed Change Reflects Appropriate Sys Coordination to Improve Availability of Diesel Generators & Acceptable

ML20198C125
Person / Time
Site:	Columbia
Issue date:	10/15/1985
From:	Rubenstein L Office of Nuclear Reactor Regulation
To:	Novak T Office of Nuclear Reactor Regulation
References
CON-WNP-0829, CON-WNP-829 TAC-59031, NUDOCS 8511110372
Download: ML20198C125 (2)

Text

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OCT I S 1985 MEMORANDUM FOR: Thomas M. Novak, Assistant Director for Licensing, DL .

FROM: L. S. Rubenstein, Assistant Director for Core and Plant Systems, DSI

SUBJECT:

WNP.2, TECHNICAL SPECIFICATION CHANGE TO ELECTRICAL POWER SYSTEM (TAC NO. 59031)

Washington Public Power Supply System proposed a change to the technical specifications related to the electrical power systems for WNP-2 by letter dated May 22, 1985. The proposed change, specifically to Surveillance Requirement 4.8.1.1.2, is to make the minimum allowable voltage uncertainty on auto starting of diesel generator units, DG-1 and DG.2, consistent with the diesel generator breaker closure permissive setpoint.

The current technical specification of WNP-2 potentially allows the establishment of a condition which could preclude operation of the diesel generators without additional operator action. Design of the Division 1 and 2 diesel generator breakers will not allow closure of the breaker until voltage is within 94% of rated voltage (3910 volt). Current technical specifications state that voltage must be allowed to be 4160 2 420 volt (3740 volt).

The 94% setpoint was established to ensure that the diesel generators will be able to accept the first load block during initial loading. Based on the voltage analysis, a minimum voltage of 3910 volt (94% of rated voltage) is established which will remain above 80% of rated voltage frcm no load to full load without operator action. The new technical specification on voltage range for starting will be between 4160 + 420 volts and 4160 - 250 volts.

This diesel generator voltage with uncertainties specifies a minimum allowable voltage for the diesel generator consistent with the permissible voltage setpoint to close the output breaker. Based on our evaluation of the change and its justification, the staff concludes that the proposed charge to the technical specifications reflects appropriate system coordination to improve the availability of the diesel generators and is, therefore, acceptable.

This completes TAC No. 59031.

OW altrod by s" t,.S.Rubwath 0511110372Ojj0$9f go L. S. Rubenstein, Assistant Director

% Q ADOM O .FP6 o* for Core and Plant Systems

[I Division of Systems Integration cc: See Page 2 iSTRIBUTION:

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OFFICIAL RECORD COPY

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cc: R. Bernero H. Thompson M. Srinivasan W. Butler J. E. Knight J. Bradfute S. Rhow l

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