ML19317F068

AO-287/74-05:on 741024,core Flood Discharge valve,3CF-1, Electrical Breaker Discovered Open & Tagged W/Padlock in Place But Not Locked.Caused by Personnel Error.Padlocks Now Rechecked After Locking

ML19317F068
Person / Time
Site:	Oconee
Issue date:	11/07/1974
From:	DUKE POWER CO.
To:
Shared Package
ML19317F057	List: ML19317F056 ML19317F061 ML19317F064 ML19317F068
References
NUDOCS 8001080760
Download: ML19317F068 (1)

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DUKE POWER COMPANY OCONEE UNIT 3 Report No.: A0-287/74-5 Report Date: November 7, 1974 Occurrence Date: October 24, 1974 Facility: Oconee Unit 3, Seneca, South Carolina Identification of Occurrence: Core flood tank discharge

. Valve breaker not locked open Conditions Prior to Occurrence: Operating at 40 percent full power

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Description of Occurrence;_

Oconee Nuclear Station Technical Specification 3.3.3 requires that the core flood tank discharge valves be open and the electrical breakers for these ,,

valves be locked open and tagged when Reactor Coolant System pressure is above 800 psi. On October 24, 1974, the Oconee Unit 3 core flood discharge valve, 3CF-1, electrical breaker was discovered open and tagged, with the

. . padlock in place but not~ locked. The lock was immediately

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relocked and

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"this was reported to the Shift' Supervisor.

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l I Des'ignati.on of Apparent Cause of Occurrence:

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The core flood discharge valve electrical bre'aker was opened and' locked The padlock was open on October 16. 1974 during startup of Oconee Unit 3.

verified locked by the utility operator and so noted in the startup pro-cedure. Apparently, the padlock had not been fully locked and fell open at a later time.

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i Analysis of Occurrence:

During the period that the motor operator breaker for core flood discharge l

valve 3CF-1 was not locked, both 3CF-1 and 3CF-2 were open and tagged open I

and both core ficod tanks were operational as required by the Technical

-Specifications. The' presence of the padlock on the motor operator breaker,

.even though it was not locked, prevented the breaker from being remotely operated. In ddition, there are two independent pos' tion detectors on

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.these valves to keep the control room operator informed of their position -

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t unlikely event that some'one would re' move the' lock'and manually close' the breaker. The health and safety of the public was not affected.

Corrective Action:

All operations personnel have been informed of this' incident and of the necessity ;to recheck the padlocks af ter locking.

8001080 L: