ML19350B952

Interim Deficiency Rept,Originally Reported 810217,re Westinghouse Valves That Failed to Close Completely Under pre-operational Test Conditions.Westinghouse Investigating. Problem Lies within Limitorque Operators.Mods Scheduled

ML19350B952
Person / Time
Site:	Comanche Peak
Issue date:	03/13/1981
From:	Gary R TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	Madsen G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV), NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
References
10CFR-050.55E, 10CFR-50.55E, TXX-3288, NUDOCS 8103240474
Download: ML19350B952 (3)

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Mr. G. L. Madsen, Chief Reactor Projects Branch U. S. Nuclear Regulatory Commission Office of Inspection & Enforcement 611 Ryan Plaza Dr., Suite 1000 Docket Nos. 50-445 Arlington, Texas 76012 50-446 COMANCHE. PEAK STEAM ELECTRIC STATION WESTINGHOUSE GATE VALVES FILE N0: 10110

Dear Mr. Madsen:

In accordance with 10 CFR 50.55(e), we are submitting the attached interim

. . report concerning Westinghouse valves that failed to close completely under Pre-operational Test Conditions. We previously reported this item to your Mr. R. G. Taylor on February 17, 1981. We anticipate submitting a follow-up report on this matter by May 22, 1981.

If we can provide any . additional information, please advise.

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Very truly yours, k~

R. . Gary t

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( Attachment cc: NRC Region IV - (0 + 1 copy)

Director, Inspection' & Enforcement - (15 copies) c/o Distribution Services Branch, DDC,~ADM.

U. S. Nuclear Regulatory Commission Washington, D. C. 20555 I- 810324047 4

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TXX-3288 Attachment March 13,1981 WESTINGHOUSE GATE VALVES Description of Deficiency Westinghouse informed TUSI that certain three (3) inch valves, Model 3GM88, 1500 pound class, had failed to close completely under pre-operational test conditions (i.e. 2700 PSID as flow approaches zero).

These conditions were less severe than the design conditions (i.e., 2750 PSID as flow approaches zero).

As a result, Westinghouse instituted an engineering investigation to determine the cause of the problem. The testing on the three inch valves indicated that the problem lies within the capabilities of the Limitorque opera tors. The investigation also indicated ' hatc the problem extends to the Westinghouse four (4) inch valves Models 4GM87, 900 pound class and 4GM88, 1500 pound class. Westinghouse; however, has yet to complete the testing and analysis for the four inch valves.

NOTE: The piablem also extends to Model 3GM99; however, concerns regarding this model do not apply to CPSES.

Safety Implications

~ The valve models listed below are being used at CPSES. Also given are the valve functions and valve location numbers.

Valve Model Location Yalve Reference Number Function 3GM88 8105 Charging Line Isolation 3GM88 8106 4GM88 8801A, B Boron Injection Tank Isolation 4GM88 8802A, B SI Pump HL Recirculating Isolation 4GM88 8803A, B Boron Injection Tank Isolation 4GM87 8821A, 8 SI Pump Discharge XDISO 4GM88 8835 SI Pump' CL Injection Isolation

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TXX-3288 It has been determined that for valv' (as identified by their valve location numbers) 8105, 8106, 8801A and B, 8802 A and B, and 8835, had the complete closur.e problem gone undetected, loss of containment building integrity during an accident condition would have been the apparent result.

Valves 8803 A and B are not considered to be pressure boundary or containment integrity related. These valves are upstream of R801 A and B and serve only to isolate the Boron Injection Tank.

Normally open valves 8821 A and B do not fall in a pressure boundary or containment isolation situation. These valves are used only to isolate the normal flow path of the CYCS from the emergency flow path. If these valves failed open in en emergency condition, the implications would practically be negligible.

Corrective Action The following modifications have been qualified by testing for the three (3) inch valves 8105 and 8106:

1. Change the operator gear ratio to insure 80% ' voltage closing capabili ty.

2. Implement limit closing control utilizing the capabilities of the spring compensators on the limitorque SB-00 operators.

We are currently working with Westinghouse and Limitorque on a schedule for implementing. the modification on the three (3) inch valves.

Westinghouse has indicated that they cannot anticipate a completion date for the analysis and testing of the four (4) inch valves.

As indicated in our cover letter, we will advise you by May 72, 1081 of the progress of these activities.

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