ML19312C860
| ML19312C860 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 10/07/1975 |
| From: | DUKE POWER CO. |
| To: | |
| Shared Package | |
| ML19312C857 | List: |
| References | |
| RO-270-75-14, NUDOCS 8001130017 | |
| Download: ML19312C860 (2) | |
Text
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DUKE POWER COMPANY OCONEE UNIT 2 Report No.:_
UE-270/75-14 October 7, 1975 Report Date:_
Evcat Date:_ September 9, 1975 Oconee Unit 2, Seneca, South Carolina Facility:
Leakage of penetration room valves in excess of Identification of Event:
J Technical Specifications Conditions Pr$or to Event: Unit at cold shutdown Description of Event:
On September 9, 1975, periodic local leak tests were performed on Oconee Unit 2 Reactor Building Purge System discharge valves 2PR-1 and 2PR-2, The test revealed and on the Purge System intake valves 2PR-5 and 2PR-6.
that leakage of 2PR-5 and 2PR-2 was in excess of the allowed limits as defined in Technical Specification 4.4.1.2.3.
After repair of 2PR-2 and subseg"ent retesting, 2PR-1 was also found to be leaking excessively.
Desil ation of Apparent Cause of Event:
Inspections were performed and it was found that 2PR-5 was not closing completely and that the seating surfaces were dry and dirty on 2PR-2.
Af ter 2PR-2 was repaired, further testing and inspection revealed that the gasket for 2PR-1 needed replacing.
Analysis of Event:
Valves 2PR-1 and 2PR-2 are redundant valves located on the discharge of the Reactor Building and are the suction valves to the Reactor Building Purge Although both valves were leaking in excess of prescribed Filtering System.
limits, any leakage past these valves during operation would pass through the Filtering System before entering the atmosphere, thereby minimizing The latest filter tests indicate filter efficiency radiological consequences.
at 99.99 percent for HEPA and 99.94 percent for charcoal.
Valves 2PR-5 and 2PR-6 are redundant valves located on the intake of the In this event, although 2PR-5 failed the Reactor Building Purge System.
Therefore, the redundant valve 2PR-6 operated properly.
leakage rate test, due to the redundancy of these valves, 2PR-6 would have maintained containment Thus, the highly integrity in the unlikely event it would be required.
effective Filtering System and the redundancy provided minimized the consequences of-this incident and it is concluded that the health and safety of the public was not affected by this event.
t 8 0 01 13 00/~'7 S
Corrective Action-The seating Adjustments were made so that 2PR-5 would close completely.
2PR-2 would close surfaces were cleaned, lubricated, and adjusted so thatLeak tests were performed and The gasket was replaced on 2PR-1.
It is felt that leakage was determined to be within acceptable limits.
properly.
h sent testing additional corrective action is not warranted and that t e preh failures.
and surveillance program is adequate to detect and correct suc l
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