ML19345B731

Final Deficiency Rept Re 801121 Part 21 Rept of Substantial Safety Hazard Concerning Omission of Seal in Contact of Speed Changing Switch for Svc Water Pumps.Caused by Design Error.Circuit Revised to Insure Speed Switch Transfers

ML19345B731
Person / Time
Site:	Summer
Issue date:	11/21/1980
From:	Nichols T SOUTH CAROLINA ELECTRIC & GAS CO.
To:	James O'Reilly Office of Nuclear Reactor Regulation
References
REF-PT21-80-317-000 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8012020434
Download: ML19345B731 (2)

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south CARollNA ELECTRIC a GAS COMPANY CotuMe:A, Sourn CanoLINA aseis ~j T.C.NicwoLs,JR. )

.c e.... ... o .cua,~. November 21, 1980 mu. c ..

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Mr. James P.' O'Reilly, Director i

• U. S. Nuclear Regulatory Commission 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 the omission of a seal in conta3t in the speed changing switch for the service water pumps, which could nave resulted in inadequate cooling water to supply to the diesel generators. This was an error in the design as submitted by the architect engineer. Details are given on the attachment.

This item is being reported under our 10CFR50.55(e) procedure. This is considered a final report on the matter.

Very truly yours, Tl @

T. C. Nichols, Jr.

JAW:TCN:rh cc: V. C. Su==er C. 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. A B. A. Bursey Mi i 1

'J. L. Skolds V 6\ l J.-B. Knotts, Jr.

-ISE (Washington)

Document 'fanagement Branch /.

NPCF/Whitaker Filc~ '

H. E. Yocom

$801202O M 8 -. - . .

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10CFR21 - SU3STANTIAL SAFETY HAZARD-

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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 pump speed changing switch

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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 The signal from the load. sequencer for the service water pump speed switch to go to high speed on loss of off site power was a momentary contact.

The speed switch operated, but then dropped back to low speed when the contact dropped out. This is a design' deficiency because the sequencer was specified this way and a seal in contact'should have been provided in the speed switch control.

If the speed switch fails to go to high speed there may not be s9fficient cooling for the diesel generators.

This was identified by startup field report 2642 dated 6/11/80.

5. Date Information of Defect Was Obtained - 7/3/80

6. Number and Location of Defect Three service water pump speed switches are involved.

7.- Corrective Action The control: circuit has been revised to-provide a seal in to insure the speed switch transfers and remains transferred. The architect engineer has

~been notified, but feels that this is an-isolated incident and no procedure or design criteria revision are_necessary.

8. < Advice to Purchasers or Licenseed None.

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