ML19317E943
| ML19317E943 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 07/01/1975 |
| From: | DUKE POWER CO. |
| To: | |
| Shared Package | |
| ML19317E938 | List: |
| References | |
| RO-287-75-07, RO-287-75-7, NUDOCS 8001070738 | |
| Download: ML19317E943 (1) | |
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DUKE POWER COMPANY OCONEE UNIT 3
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R_efprt No.: UE-287/75-7
...y Report Datel July 1, 1975 Event Date: May 23, 1975 Facility: Oconee Unit 3, Seneca, South Carolina Identification of Event:
Failure of valve 3FDW-108 to operate Conditions Prior to Event:
Unit at full power Description of Event:
On May 23, 1975, the quarterly performance test of Engineered Safeguards valves was conducted on Oconee Unit 3.
The B steam generator sample line isolation valve, 3FDW-108, failed to indicate closed after being given the close command. This valve is normally closed during operation and is opened only for steam generator sampling. The valve has been closed and locked until corrective maintenance can be performed.
Designation of Apparent Cause of Event:
The apparent cause of this event was a weak spring in the valve operator.
The valve was found to be remotely operable with no pressure in the sample line; however, due to a weak spring in the operator, it would not close under pressure.
Analysis of Event:
Valve 3FDW-108 is the Reactor Building containment isolation valve for the B steam generator sample line. This valve is one of two redundant valves which are closed by an Engineered Safeguards signal in the unlikely event containment integrity is required. This incident did not affect the redundant isolation valve.
It is concluded that the health and safety of the public was not affected by this incident.
Corrective Action:
A new spring has been ordered for the operator of valve 3FDW-108. Until the valve operator can be repaired, 3FDW-108 has been locked closed with the redundant isolation valve, 3FDW-107, also closed.
Failure Data:
A previous failure was experienced with valve 3FDW-108 and was discussed in report UE-287/74-4. At that time, no cause was found for the valve's failure to close in a specified time.
After further testing, the valve was returned to service. The apparent cause of both failures has now 1
been identified and will be corrected.
8001070 7 3 I
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