ML19317D726

RO 269/77-10: on 770316,1FDW-108 Feedwater Containment Isolation Valve Failed to Close Under Sys Pressure Caused by Hardening of Valve Packing.Valve 3FDW-108 Repacked & Tested. Program Will Be Developed to Adjust or Replace Packing

ML19317D726
Person / Time
Site:	Oconee
Issue date:	04/15/1977
From:	DUKE POWER CO.
To:
Shared Package
ML19317D722	List: ML19317D718 ML19317D726
References
RO-269-77-10, NUDOCS 7912100494
Download: ML19317D726 (1)

Text

.. ~ DUKE POWER COMPANY _ l OCONEE UNIT 1 l

Report No.: R0-269/77-10 0

Report Date: April 15, 1977 Occurrence Date: March 16, 1977 i Facility: Oconee Unit 1, Seneca, South Carolina Identification of Occurrence: Feedwater containment isolation valve 1FDW-108 inoperable Conditions prior to Occurrence: Unit at 91 percent full power Description of Occurrence:

On March 16, 1977, following chemical sampling of the "lB" once-through steam generator, feedwater containment isolation valve 1FDW-108 failed to close under system pressure. This valve, located outside the Reactor Building, la part of the chemical sampling system and provides containment isolation following an ES actuation. The redundant valve,1FDW-107, incated-inside the Reactor Building was closed and locked as required by Oconee Technical Specification 3.6.4.b.2.

Apparent Cause of Occurrence:

Examination of the valve indicated that the inability of the valve to cycle properly resulted from the hardening of the valve packing.

Analysis of Occurrence:

Valve 1FDW-108 was properly isolated in compliance with Technical Specifica-tion 3.6.4.b.2 by securing redundant valve 1FDW-107 in the closed position.

In the event that containment isolation had been required prior to securing valve 1FDW-107, valve 1FDW-107 would have closed upon an ES actuation. Con-tainment integrity was not affected by this incident and it is thus concluded that the health and safety of the public were not affected.

Corrective Action:

Valve 3FDW-108 was repacked and its operability verified. To prevent recur-rence of this incident, the following action will be taken.

A program will be developed to periodically adjust or replace packing on the FDW-106 and FDW-108 valves on all three units. This program will include examination and, as necessary, replacement of the packing on these valves during each unit's next refueling outage. .i review will also be made of different types of packing which could eliminate hardening problems.

To determine if these valves need to be changed to a different design and/or different operator, the operation and maintenance histories of these valves are being reviewed and evaluated.

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7 91210 0 N

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