05000373/LER-1983-117, Updated LER 83-117/03X-1:on 830920 & 30,RHR HX B Outlet Valve Limit Switches Temporarily Changed,Allowing Wedge Travel to Stop

Updated LER 83-117/03X-1:on 830920 & 30,RHR HX B Outlet Valve Limit Switches Temporarily Changed,Allowing Wedge Travel to Stop

ML20081B994
Person / Time
Site:	LaSalle
Issue date:	02/14/1984
From:	Diederich G, Peters M COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
LER-83-117-03X, LER-83-117-3X, NUDOCS 8403120095
Download: ML20081B994 (3)

LER-2083-117, Updated LER 83-117/03X-1:on 830920 & 30,RHR HX B Outlet Valve Limit Switches Temporarily Changed,Allowing Wedge Travel to Stop

Event date:
Report date:
3732083117R00 - NRC Website

text

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s MPDEATED 1(EPORT PREVIOUS REPORT '

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g l On 9-20-83 at 0300 with Unit One in Cold Shutdown, the B RHP. Heat Exchanner Outlet l

g l Valve failed to open via tha. motor operator or manually. The inocerability of this I

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CAUSE DESCRIPTION AND CORRECTIVE ACTIONS 27 is believed that the valve can become inocerable in the close oosition due to waterj R ol lit

~ Since the bonnet cavity does not have a mechanism 1 g Ibelno tracoed in the bonnet cavitv.

f to vent off the entracoed water for valve ooenino, the wedae is hydraulically lockep g1 on the closed position. At the recommendation of Anchor Darling, Valve ,oAnn +r Mfg., the up1 ic c e nme A hv j ee w rerflu r e-s,s, a s e,,, L *%* +6 ,

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1. LER NUMBER: 83-117/03X-1

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II. LASALLE COUNTY STATION: Unit I lil. DOCKET NUMBER: 050-373 IV. EVENT DESCRIPTION:

On 9-20-83 at 0300 with the unit in cold shutdown, the B RHR Heat Exchancer Outlet Valve (1E12-F0038) failed to open via the notor operator or nenually.

The inoperability of this valve, while in the closed position, made B shut-down cooling and B suppression pool cooling inoperative.

V. PROBABLE CONSEQUENCES OF THE EVENT:

The A shutdown cooling loop was operable t'o control decay heat. Conservative calculations also indicated the reactor water cleanup system was capable af removing the decay heat at the time of this event. The safety of the plant and public was not affected by this event.

VI. CAUSE:

The IE12-F003B is a flex wedge gate-valve manufactured by the Anchec Darlino Co. The 1E12-F003B valve.was disassembled via work request L27780. The valve internals were inspected by representatives of Anchor Darling Co., Mark Controls Corp., and Ceco. The internals were evaluated as extremely good.

A wedge to seat rings contact test (Blue Test) indicated approximately 1003 contact. While performing Work Request L29638, written to remove and replace the motor operator for the valve internals inspection, the ooerator motor winding insulation was found to be burnt. The valve was reassembled, motor operator (with a new motor) was reolaced, and the valve satisfactorily cycled.

The valve subsequently again became locked in t,he closed position while con-tinuing to test the valve during various conditions of B Shutdown Cooling.

It is believed that the valve can become inoperable in the close position due to water being trapped in the bonnet cavity. Since the bonnet cavity does not

.have a mechanism to vent off the entrapped water for valve opening, the wedge is hydraulically locked in the closed position.

Vll. CORRECTIVE ACTION:

At the recommendation ~of Anchor Darling, the valve limit switches were l temporarily changed such that the wedge travel is stopoed by position and not by torque. This change would allow the water entrapoed in the bonnet

- cavity to be vented through the upper seat rings to wedge seat as the valve '

is opened. A temoorary system change LAP 240-6 Att. B 1-700-83 and work request L29978 were performed to accomplish the above recommendation. The valve has since been tested without failure several times under different conditions of B PHR Shutdown Cooling. A.I.R. 01-83-67128 has been issued to scrutinize the performance of IE12-F003B over the next two excursions of the unit to cold shutdown. If the temporary system change to the valve resolves the valve becoming inoperative in the close position, a oermanent modification will be made in accordance with Anchor Darling's reconmendations.

Prepared by: M. A. Peters t

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Marseilles,ll!inois 61341 s Telephone 815/357-6761 February 15, 1984 James G. Keppler Regional Administrator Region lII U.S. Nuclear Reaulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137

Dear Sir:

Reportable Occurrence Report #81-117/03X-1 Docket #050-373 is beina submitted to your office to supersede prevleusly submitted Reportable Occurrence Report

1. 83-117/03L-0, in accordance with NUREG-0161, " Instructions for Preparation of Data Entry Sheets for Licensee Event Report (LER) File"; General Instruction No. 3 G. J. Diede ich Superintendent LaSalle County Station GJD/GW/rg Enclosure cc: Director of Inspection & Enforcement Director of Manaaement Information & Program Control U.S. NRC Document Management Branch INPO-Records Center Flie/NRC MAR 6 1984'

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