ML19329A718

RO 287/77-04:on 770322,feedwater Containment Isolation Valve 3FDW-106 Found Inoperable.Caused by Valve Packing Hardening. Valve 3FDW-106 Repacked & Tested.Periodic Valve Adjustment Program to Be Developed.Valve Operation & Maint Evaluated

ML19329A718
Person / Time
Site:	Oconee
Issue date:	04/20/1977
From:	DUKE POWER CO.
To:
Shared Package
ML19329A717	List: ML19329A716 ML19329A718
References
RO-287-77-04, RO-287-77-4, NUDOCS 8001090694
Download: ML19329A718 (1)

Text

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• DUKE POWER COMPANY ,.

OCONEE UNIT 3 m

Report No.: R0-287/77-4 Report Date: April 20, 1977 Occurrence Date: March 22, 1977 Facility: Cconee Unit 3, Seneca, South Carolina Identification of Occurrence. E-odwater containment isolation valve 3FDW-106 inoperable Conditions Prior to Occurrence: Unit at 100 percent full power Description of Occurrenes:

OnMarc$ 22, 1977, following chemical sampling of the "3A" once-through steam generator, feedwater containment isolation valve 3FDW-106 ; ailed to close under system pressure. This valve, located outside thc Reactor Building, is part of the checical sampling system and provides containment isolation following an ES actuation. The redundant valve, 3FDW-105, located inside the Reactor Building was closed and locked as required by Oconee Technical Specification 3.6.4.b.2.

Apparent Cause of Occurrence:

The inability of valve 3FDW-106 to cycle properly was determined to have resulted irom hardening of the valve packing, jnalysis of Occurrence:

Valve 3FDW-106 was properly isolated in compliance with Technical Specifi-cation 3.6.4.b.2 by securing redundant valve 3FDW-105 in the closed position.

In the event that containment isolation had been required prior to securing valve 3FDW-105, valve 3FDW-105 would have closed upon an ES actuation.

Containment integrit', was not affected by this incident and it is this concluded that the health and safety of the public were not affected.

Corrective Action:

Valve 3FDW-106 was repacked and its operability verified. To prevent recurrence of this incident, the following action will be taken.

A program will be developed to periodically adjust or replace packing on u5 FDW-106 and FDW-108 valves on all three units. This program will aclude examination and, as necessary, replacement of the packing. At present, all FDw-106-and -108 valves have been repacked during the last 4 months except 1FDW-106, 2FDW-108 and 2FDW-106. These valves will be examined and repacked as necessary during each units n, ext.-gef,ueling outage.

A review will also be made of different types of. packing which could eliminate hardening problems, git '.a 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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