NUREG-0827, Accepts 851114 Request for Deferral of Remaining Mod to Reactor Protection Sys,Including Installation of Isolation Devices & Separation of Power Supplies,Until 1987 Refueling Outage

Accepts 851114 Request for Deferral of Remaining Mod to Reactor Protection Sys,Including Installation of Isolation Devices & Separation of Power Supplies,Until 1987 Refueling Outage

ML20138R392
Person / Time
Site:	La Crosse File:Dairyland Power Cooperative icon.png
Issue date:	12/23/1985
From:	Zwolinski J Office of Nuclear Reactor Regulation
To:	Taylor J DAIRYLAND POWER COOPERATIVE
References
RTR-NUREG-0827, RTR-NUREG-827 NUDOCS 8512310245
Download: ML20138R392 (3)

Text

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December 23, 1985 Docket No.:

50-409 Mr. James W. Taylor General Manager Dairyland Power Cooperative 2615 East Avenue South La Crosse, Wisconsin 54601 9

SUBJECT:

LACROSSE BOILING WATER REACTOR (LACBWR) - NUREG-0827 SECTION 4.26.3 ISOLATION BETWEEN REACTOR PROTECTION SYSTEM CHANNELS AND POWER SUPPLIES In a letter dated September 29, 1983 Dairyland Power Cooperative (DPC) consnitted to several modifications to the reactor protection system including installation of isolation devices and separation of power supplies. A DPC letter of January 3,1985 noted that all except one of these items would be completed during the 1985 refueling outage and requested deferral of the remaining chanae (separation of power supplies for the two power to flow channels) until the following outage (1986 refueling). The reason for the deferral was to avoid overloading the static inverter which was to be replaced with a larger one during the 1986 outage.

This deferral was accepted by the staff by letter dated May 16, 1985.

Subsequently, by letter dated November 14, 1985, DPC requested that the remaining modification be deferred until the 1987 refueling outage. This letter noted that DPC is replacing the nuclear instrumentation system at LACBWR, Based on the equipment delivery date, the nuclear instrumentation will not be available to install during the 1986 outage. As part of this replacement, the power-to-flow circuitry will need to be modified. Thus, if the power supply modification were done during the 1986 outage, significant rework on the instrumentation circuitry would then be needed during the following outage. Deferral would permit a coordinated and simplified modification process. At present, the two channels of power-to-flow logic are supplied from the same power supply in a one-out-of-two logic. Loss of ac power to a channel will result in tripping, that is, accomplishing its required function.

l Considering the modifications already made to the reactor protection systen.

l the low likelihood of a fault in the common power supply preventing fulfillment l

1 0512310245 0D1223 i

PDH ADOCK 05000409 PDR l

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December 23, 1985 Mr. James Taylor of the safety function and the benefits of an integrated design modification, the staff considers that the proposed completion schedule for this item is acceptable.

Original signed by:

J. Zwolinski John A. Zwolinski, Director BWR Project Directorate #1 Division of BWR Licensing cc: See Next Page 4

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Mr. James W. Taylor Dairyland Power Cooperative La Crosse Boiling Water Reactor CC*

Fritz Schubert, Esquire Clarence Riederer, Chief Engineer Staff Attorney Wisconsin Public Service i

Dairyland Power Cooperative Comission i

2615 East Avenue South Post Office Box 7854 l

La Crosse, Wisconsin 54601 Madison, Wisconsin 53707 t

0. S. Heistand, Jr., Esquire Morgan, Lewis & Bockius 1800 M Street, N.W.

t Washington, D.C.

20036 i

Mr. John Parkyn, Plant Manager La Crosse Boiling Water Reactor Dairyland Power Cooperative 3

P. O. Box 275 Genoa, Wisconsin 54632 l

U.S. Nuclear Regulatory Comission l

Resident Inspectors Office l

Rural Route #1, Box 276 Genoa, Wisconsin 54632 Town Chaiman Town of Genoa l

Route 1 l

Genoa, Wisconsin 54632 i

e Chairman, Public Service Comission of Wisconsin j

Hill Fams State Office Building Madison, Wisconsin 53702 Regional Administrator, Region !!!

U.$. Nuclear Regulatory Comission 799 Roosevelt Road Glen Ellyn, Illinois 60137 J

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