ML19345B740

Final Deficiency Rept,Originally Identified 800416,re Broken Torque Switches on Limitorque Valve Operators,Reported Under 10CFR21.Design Criteria Revised Concerning Limitorque Operators on Butterfly Valves

ML19345B740
Person / Time
Site:	Summer
Issue date:	11/21/1980
From:	Nichols T SOUTH CAROLINA ELECTRIC & GAS CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
REF-PT21-80-316-000 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8012020445
Download: ML19345B740 (2)

Text

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SOUTH CAROLINA ELECTRIC a GAS COMPANY m , , ,,e c .. . . ..

CotuMe A, Souta CamouMA 29218 i v.c p.[,$.I.*.E'.$,. Noyember 21, 1980 Nght.e C+, tges Mr. James P. O'Reilly, . Director ,

U. S. Nuclear Regulatory Commision '1

.s Region II, Suite 3100 101 Marietta Street, N.~ W.

Atlanta, Georgia 30303

Subject:

Virgil C. Summer Nuclear Station.

Reportable Substantial Safety Hazard 10CFR21 Docket No. 50/395

Dear Mr. O'Reilly:

On 11/21/80, a substantial safety. hazard as defined by 10CFR21 was reported to Mr. John K. Rausch at the' NRC Region II office. The item involved is broken torque switches on limitorque valve operators. We are reporting this under 10CFR21, because the problem is a design error. The design should have incorporated a limit switch rather than a torque switch. Details are given on the attachment. i This item is being reported under our 10CFR50.55(e) procedure. This is considered a final report on the matter.

Very truly yours,

T. C. Nichols, Jr.

JAW:TCN:rh cc: V. C. Summer G. H. Fischer T. C. Nichols, 'Jr.

E. H. Crews,-Jr.

O. S. Bradham D. A. Nauman O. W. Dixon, Jr.

R. B. Clary W.'A. Williams, Jr.

' B. A. Bursey J. L. Skolds J. B..Knotts, Jr. @ 1

\

, H. E. Tocom V.

I&E (Washington)

Document. Management Branch d NPCF/Whitaker -

File 1

80120l20 N ;g-

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O 10CFR21 - SUBSTANTIAL SAFETY HAZARD

1. Name and Address of Reporting Individual James A. Wactor P. O. Box 764 Columbia, South Carolina 29218

2. Identification of Basic Component Service water discharge valves limitorque operators control circuit

3. Identification of Firm Supplying Component Gilbert Associates, Inc.

P. O. Box 1498 Reading, Pennsylvania 19603

4. Nature of Defect, Substantial Safety Hazard Created, and Evaluation Torque avitches were broken on the three service water discharge iso-lation valves. This is a design error since the valves should have closed on a limit switch rather than a torque switch. The torque switch would not work on these valves, because they were butterfly type valves and did not provide enough seating torque.

The valves could jam in the closed position, resulting in loss of service water and in turn loss of diesel generator and component cooling.

This was identified by startup field report 2423 dated 4/16/80.

5. Date Information of Defect Was Obtained - 5/30/80

6. Number and Location of Defect Three service water discharge volve limitorque operators were involved.

7. Corrective Action The controls are being revised on these three valves and four other similar valves. The manufacturer has been contacted to determine if there was any problem with the switch. His response has been negative. The architect engineer has been notified, and the design criteria is being re-vised concerning limitorque operators on butterfly valves.

8. Advice to Purchasers or Licensees None.

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