ML20002D060
| ML20002D060 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 11/20/1980 |
| From: | Woolever E DUQUESNE LIGHT CO. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| Shared Package | |
| ML20002D059 | List: |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, 2DLC-3806, NUDOCS 8101190279 | |
| Download: ML20002D060 (4) | |
Text
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e yq 2DLC-3806 (412) 456-6000 435 S.atm A.m M. Pa.
' November 20, 1980 United States Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, PA 19406 ATTENTION:
Mr. Boyce H. Grier, Director
SUBJECT:
BEAVER VALLEY POWER SIATION - UNIT NO. 2 Docket No. 50-412 3" MOV Gate Valves in Safety Injection and Chemical and Volume Control Svstem - Sicnificant Deficiency 80-06 Gentlemen:
Westinghouse has notified us that problems were encountered during preoperational testing at a domestic station and at a foreign station of three-inch gate valves manufactured by their Electro-Mechanical Division.
Beaver Valley Unit No. 2 has received several of the subject valves as part of the NSSS scope of supply. This problem was reported to your office on October 29, 1980 as a significant deficiency.
An investigation into the above valve deficiency is currently underway.
Pursuant to the requirements.of 10CFR5 0. 55 (e ), enclosed is
" Interim Report on 3" MOV Gate Valves in Safety Injection and Chemical and Wlume Control System at Beaver Valley Power Station - Unit No.
2."
We plan to issue another interim report on June 1, 1981.
DUQUESNE LIGHT CCMPANY By
_ r.
E UJ. Woolever Vice President Enclosure cc:
Mr. V.
Stello (15)
Mr. K. Jabbour 8101190Q p
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Interim Report c't 3" MOV Gate Valves in Safety Injection and Chemical and Volume Control System at Beaver Vallev Power Station - Unit No. 2
SUMMARY
Problems were encountered during pre-operational testing at a do-mestic station and at a foreign station of three-inch MOV Gate Valves manufactured by the Westinghouse, Electro-Mechanical Division.
These valves are classified as " active" valves (i.e., mechanical operation is required to accomplish a safety function and are utilized in the Chemical and Volume Control System and the Emergency Core Cooling System).
The tested val.ves failed to completely close during preoperational test conditions which are less severe than the equipment specification design.
conditions.
IMMEDIATE ACTION TAKEN Reject tags have been placed on the valves identified by Westinghouse and listed in the attachment, " Active" Valve Applications.
DEFICIENCY During pre-operational 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, Class I Model 3GM88,1500 lb. class. Westinghouse furnishes this valve to its customers in Class 1, 2 and 3 applications.
In the Class 2 and 3 applications the Identification Number, only, is changed to GM78 and GM58, respectively.
Tne tested valves failed to completely close under pre-operational test conditions (i.e., approximately 2700 psi as flow approaches zero) which are less severe than the equipment specification design conditions (i.e.,
2750 psi as flow apprcaches zero).
The valves stroked to significantly restrict flow, but the full stroke was not accomplished to trip the 91osed" position indication contacts in the motor operator or to seat the vaire disc within the valve bcdy.
In addition to the Model 3GM88, the later redesign version, Model 3GM99, may be subject to the same problem.
It has been determined that several of these valves 3.re classified as
" active" valves (i.e., mechanica". operation is required to accomplish a safety function and are utilin.a in the Chemical and Volume Control System and the Emergency Core Cvoling System.
The functional requirements for
" active" valves include closure under operating pressure / flow conditions.
Since the subject valves are utilized in " active" applications on Westinghouse non-operating plants, the subject f ailure to completely close is considered reportable to nonoperating plants under title 10CFR50.55 (e).
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l As part of this review, it was determined. hat the functional j
requirement pressure / flow condition under which the valves must close may be significantly less than the preoperational test and equipment specifi-cation conditions under which the subject valves failed to close.
Consequently, it is possible that complete closure of the subject valves may be accomplished under actual operating conditions even though co=plete closure was not accomplished under preoperational test conditions.
For example, the operating conditions under which one valve at the domestic station is required to function is approximately 1200 psi as flow approaches zero, instead of the pressure conditions at which the valve failed to close.
1 ANALYSIS OF SAFETY IMPLICATIONS
' Analysis of the safety implications will be provided in the final report.
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CORRECTIVE ACTION TO REMEDY DEFICIENCY The corrective action to remedy the deficiency is currently under investigation and will be provided in the final report.
ADDITIONAL REPORTS An interim report will be issued on June 1, 1981.
The date for submittal of the final report will be indicated at that time.
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" ACTIVE" VALVE APPLICATI0ilS Valve Valve Maximum aP (psi)
Functio.n Location as Flow Approaches Zero Number Equipment Functional Specification Requirement CHEMICAL.AND WLUME CONTROL SYSTEM Charging 8107 2750
- 2700, Line 8146 Isolation Charging Pump Mini-
. flow Iso.
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SAFETY INJECTION SYSTEM C
BIT Iso.
8801A 1200 8801B 8803A
c 88038 '
Hot Leg 8814
- Isolation 8816
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Cold Leg 8885 Reci rc.
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