05000338/LER-1979-080-03, /03L-0 on 790608:during Power Escalation,Axial Flux Difference Deviated More than +5% from Target for 16 Minutes,Contrary to Tech Specs.Caused by Withdrawal of Control Rods

/03L-0 on 790608:during Power Escalation,Axial Flux Difference Deviated More than +5% from Target for 16 Minutes,Contrary to Tech Specs.Caused by Withdrawal of Control Rods

ML19269E522
Person / Time
Site:	North Anna
Issue date:	06/27/1979
From:	Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19269E509	List: 05000338/LER-1979-075-03, /03L-0 on 790604:during Steady State Operation, Axial Flux Difference Deviated Over 5% from Target for Two Minutes,Contrary to Tech Specs.Caused by Xenon Oscillation Initated by Rod Operability Test.Power Reduced by 2% 05000338/LER-1979-080-03, /03L-0 on 790608:during Power Escalation,Axial Flux Difference Deviated More than +5% from Target for 16 Minutes,Contrary to Tech Specs.Caused by Withdrawal of Control Rods 05000338/LER-1979-081-03, /03L-0 on 790608:individual Rod Position Indicators M-10 & D-10 Placed in Test Status,Contrary to Tech Specs.Caused by Repair Work to Remove Previously Installed Jumper.Calibr Performed ML19269E508
References
LER-79-080-03L, LER-79-80-3L, NUDOCS 7906290215
Download: ML19269E522 (2)

LER-1979-080, /03L-0 on 790608:during Power Escalation,Axial Flux Difference Deviated More than +5% from Target for 16 Minutes,Contrary to Tech Specs.Caused by Withdrawal of Control Rods

Event date:
Report date:
3381979080R03 - NRC Website

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This event is contrary to T.S. 3.2.1.

Since therel was less than one hour penalty accumulation, operation was allowed to continue as Der i

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33 34 35 36 31 43 41 42 43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h The cause of the AFD deviation was a withdrawal of the control rods, during power g j escalation.

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Attachment:

Page 1 of 1 Docket No. 50-338 Report No. LER 79-080/03L-0

Description of Event

On 6/8/79, during a power escalation, the Axial Flux Difference deviated greater than +5% from target for a 16 minute duration.

This event is contrary to T.S. 3.2.1.

Since there was less than one hour penalty accumulation, operation ~ was allowed to continue as per Action Statement a.2 of T.S. 3.2.1.

This event is reportable as per T.S. 6.9.1.9.b.

Probable Consequences of Occurrence Surveillance of the Axial Flux Difference assures that the limits of the heat flux hot channel factor are not exceeded during normal operation or in the event of Xenon redistribution following power changes.

This provides protection against exceeding the DNBR and peak fuel clad temperatures.

Since the AFD was returned to its limit within the time allotted, there was no effect upon the safe operation of the plant. As a result, the public health and safety was not af fected.

There are no generic implications.

Cause of Occurrence The AFD deviation was the result of rod withdrawals during the power escalation.

Immediate Corrective Actior.:

Corrective Action was to dilute the control rods in, which restored the AFD to within the target band.

Scheduled Corrective Action:

Surveillance of the AFD continued during the power escalation to prevent further AFD deviations.

Actions Taken to Prevent Recurrence No further actions are required.

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