ML19351E545

Interim Deficiency Rept Re Failure of Westinghouse 3-inch Gate Valves to Close,First Reported on 801030.Addl Info Is Still Being Obtained & Corrective Mods Are Being Developed. Followup or Final Rept Will Be Sent in First Quarter 1981

ML19351E545
Person / Time
Site:	Wolf Creek, Callaway
Issue date:	11/26/1980
From:	Petrick N STANDARDIZED NUCLEAR UNIT POWER PLANT SYSTEM
To:	Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
10CFR-050.55E, 10CFR-50.55E, SLNRC-80-54, NUDOCS 8012100440
Download: ML19351E545 (2)

Text

>

8 0 ,s -*

SNUPPS Stenderdized Nveleer Umt Power Plant Systen, s ca.cwry need Nicholas A.Petrick

• I lead 20 50 Executive Director

,7 ,o November 26, 1980 C m E

q.  ; g n n.-'

SLNRC 80-54 FILE: 0491.10.2

. SUBJ: Failure of Containment Isolation Valves Mr.~Boyce Grier Director, Region I Office of Inspection and Enforcement U. S. Nuclear Regulatory Comission -

631 Park Avenue King of Prussia, Pennsylvania 19406 Docket Nos: STN 50-482, STN 50-483, STN 50-486

Dear Mr. Grier:

On October 30, 1980, SNUPPS infomed the Nuclear Regulatory Comission, Region I Office of Inspection and Enforcement, of a potential deficiency involving the failure to close of valves that are identical to contain-ment isolation valves planned for use at the SNUPPS plants. The infor-mation was comunicated by telephone to Mr. Joseph Mattia of your staff pursuant to 10CFR50.55(e).

During preoperational testing at a domestic station and at a foreign station, problems were encountered when testing the Westinghouse Electro-Mechanical Division manufactured three inch gate valves, Model 3GM88,1500 pound class. 'n certain applications the identification number is GM78 or GM58. Model 3GM99 may be subject to the same problem.

The tested valves failed to completely close under preoperational test conditions (approx 4.nately 2700 psi as flow approaches zero) whicn are less severe than the equipment saecification design conditions (2750 psi as flow approaches zero). The valves stroked to significar.tly restrict flow, but the full stroke was not accomplished. The full stroke should have tripped the " closed" position indication contacts in the motor operator and seated the valve disc within the valve body.

In the SNUPPS design the subject valves are to be used as the isolation valves in the normal charging path to the regenerative heat exchanger in the Chemical arid Volume Control System. These valves (valve location nos. HV 8105 and HV 8106, FSAR figurc 9.3-8 sheet 3) are normally open and close on a safety injection signal to isolate the normal charging 00

.s 801210s @ .

-- -w

SLNRC 80-54 Page Two path.- If both valves failed to close in an accident situation, proper isolation between normal charging and high head safety injection would not be attained. Therefore, this matter is considered reportable under the provisions of 10CFR50.55(e).

SNUPPS is continuing to obtain additional information concerning this problem and to develop the appropriate corrective modifications. A schedule for the ccrrective action has not been established. However, SNL'."PS will submit a follow-up or final eport to the NRC on this matter during the first quarter of 1981.

Ve r truly yours, ewt j Nicholas A. Pet RLS/lc .

cc: Mr. James G. Keppler, Director, Region III, USNRC Mr. Karl V. Seyfrit. Director, Region IV, USNRC (3 V Victor Stello Jr., Office of I&E, USNRC, Washington, DC W. A. Hansen - NRC/Callaway T. A. Vandel - NRC/ Wolf Creek

-