ML20084E243

AO 50-244/74-06: on 740422,RHR Pump Suction Valve 851B Failed to Open.Caused by Valve Being Too Tightly Sealed in Closed Position.Operating Procedures for Heatup Changed

ML20084E243
Person / Time
Site:	Ginna
Issue date:	05/02/1974
From:	Amish K ROCHESTER GAS & ELECTRIC CORP.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20084E247	List: ML20084E243 ML20084E250
References
AO-50-244-74-06, AO-50-244-74-6, NUDOCS 8304140467
Download: ML20084E243 (3)

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' ROCHESTER GAS AND ELECTRIC CORPORATION e 89 EAST AVENUE, ROCHESTER, N.Y.14549 agits w Aviss vess>=oir '.-

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m Mr. James P. O'Reilly, Director Directorate of Regulatory Operations Region I U. S. Atomic Energy Commission 631 Park Avenue .

King of Prussia, Pennsylvania 19406

Subject:

Abnormal Occurrence 74-6: Failure of Valve 851B to open R. E. Ginna Nuclear Power Plant, Unit No.1 Docket No. 50-244

Dear Mr. O'Reilly:

In accordance with Technical Specifications, Article 6.6.2a, the attached report of Abnormal Occurrence 74-6 is hereby submitted.

Very truly yours,

' Keith W. Amish Attachment xc: Mr. John F. O' Leary

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1. Report Number: 244/74-6 2a. Report Date: May 2,1974 2b. Occurrence Date: April 22,1974

3. Facility: R. E. Ginna Nuclear Power Plant, Unit No.1

4. Identification of Occurrence:

This abnormal occurrence is defined by Technical Specifications Article 1.9 d: Failure of one or more components of an engineered safety feature or plant protection system that causes or threatens to cause the ,

feature or system to be incapable of performing its intended function.

5. Conditions Prior to Occurrence:

Routine heatup from Cold Shutdown to Hot Shutdown Primary System Pressure 1,000 psig Primary System Temperature 3800F.

6. Descrintion of Occurrence:

- , At approximately 1530 hours0.0177 days <br />0.425 hours <br />0.00253 weeks <br />5.82165e-4 months <br /> on April 22, 1974, the control board operator attempted to open Containment Sump B outlet to Residual Heat ,

Removal Pump suction valve 851B electrically from the Con. trol Board to position it for its normal operating condition. When the valve failed to open the electricians noted that the motor was drawing an excessive uusi eni luod. A utechanic and a pipeilliet enieted Line Cunialianent and were able to manually move the valve disc off the valve seat. Once the j valve was disengaged from the seat the valve was capable of ' electrical ,

operation. The valve was stroked three times with no difficulty. The running current was measured at 1.8 Amps to open and close the valve '

and the torque close current reading was 2.0 Amps.

7. Desianation of Accarent Cause: ,

The cause of the failure of the valve to open is due to its being too tightly seated in the closed position. A definite cause for the valve being seated so tightly has not been determined, but it is believed that it was due to pressure developed between valves 850B and 851B. The

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pipe between the valves was full of water and the RHR system on the .

opposite side of valve 850B was heated to approximately 3000F before t the Residual Heat Removal System was removed from service. Heat transmitted through the valve 850B would cause pressure to develop in  ;

a solid system between valves 850B and 851B.

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8. Analysis of Occurrence:

During plant operation this valve is normally opened so that a i need for its opening does not exist. If, however, it were to fail in the

! closed position when it was needed for recirculation of the water in the Containment following a loss of coolant accident, valve 851A would ~

l still be available to supply suction from Containment Sump B.

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9. Corrective Action: .

Proper operation of the valve was verified before returning it to service. The operating procedures for plant heatup are being reviewed and changed to allow for the valve to be opened prior to system heatup.

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l 10. Failure Data:

a. This valve previously had failed to close fully on October 14, 1970 due to a loosened stem nut locknut.

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! b. The valve is a Darling Valve and Manufacturing Company Motor j Operated 10" Gate Valve.

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