ML19317E301

LER 78-022/01T-0:on 780914,during Procedure IP/0/A/0201/0IA, Both Channels of Level Instrumentation on Core Flood Tank 2A Out of Tolerance.Cause Not Apparent.Channels Recalibr

ML19317E301
Person / Time
Site:	Oconee
Issue date:	09/28/1978
From:	Ken Wilson DUKE POWER CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19317E300	List: ML19317E299 ML19317E301
References
LER-78-022-01T, LER-78-22-1T, NUDOCS 7912170523
Download: ML19317E301 (1)

Text

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DUKE POWER COMPANY OCONEE UNIT 1 Report Number: RO-269/78-22 Report Date: September 28, 1978 Occurrence Date: September 14, 1978 Facility: Oconee Unit 1, Seneca, South Carolina Identification of Occurrence: Core Flood Tank Level Instrument Out-of-Calibration Condition Prior to Occurrence: Refueling Shutdown Description of Occurrence:

During the performance of instrument procedure IP/0/A/0201/01A (Core Flood Tank (CFT) Level Instrument Calibration), both level instruments for CFT 2A were calibrated. During a review of the data on September 15, 1978 it was determined that the instruments had been out of tolerance and below the limit in specification 3.3.3. One indicated high by 0.18 feet and the other by 0.24 feet.

Cause of Occurrence:

There was no apparent cause of this accurrence. This has not been a recurring problem although a similar occurrence did occur on Unit 2 in January 1978.

(RO-270/78-1)

Analysis of Occurrence:

The core flood system is one of three means designed to provide emergency core cooling (ECCS), the others being the high and low pressure injection systems.

In the event of a postulated accident all of these systems would have operated to maintain the core covered and to cool the core. The combined volume of water in both core flood tanks was always above the minimum amount required.

The health and safety of the public were not endangered.

Corrective Action:

Both channels of level instrumentation were calibrated.

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