05000338/LER-1980-098-03, /03L-0:on 801123,while Operating in Mode 1,neutron Flux Distribution Exceeded Axial Flux Difference Target Band.Caused by Xenon Transient.Control Rods Inserted,Causing Flux Distribution to Shift Downward

/03L-0:on 801123,while Operating in Mode 1,neutron Flux Distribution Exceeded Axial Flux Difference Target Band.Caused by Xenon Transient.Control Rods Inserted,Causing Flux Distribution to Shift Downward

ML20002B015
Person / Time
Site:	North Anna
Issue date:	12/04/1980
From:	Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20002B014	List: 05000338/LER-1980-098, Forwards LER 80-098/03L-0 05000338/LER-1980-098-03, /03L-0:on 801123,while Operating in Mode 1,neutron Flux Distribution Exceeded Axial Flux Difference Target Band.Caused by Xenon Transient.Control Rods Inserted,Causing Flux Distribution to Shift Downward
References
LER-80-098-03L, LER-80-98-3L, NUDOCS 8012090319
Download: ML20002B015 (2)

LER-1980-098, /03L-0:on 801123,while Operating in Mode 1,neutron Flux Distribution Exceeded Axial Flux Difference Target Band.Caused by Xenon Transient.Control Rods Inserted,Causing Flux Distribution to Shift Downward

Event date:
Report date:
3381980098R03 - NRC Website

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D U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT CONTROL BLOCK-/ /'/ / / / / (1)

(PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION)

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_/V/A/N/A/S/1/ (2)

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LICENSEE CODE LICENSE NUMBER LICENSE TYPE CAT LL/-(6)

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' DOCKET NUMBER EVENT DATE REPORT DATE EVENT' DESCRIPTION AND PROBABLE CONSEQUENCES (10)

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On November 23, 1980 while operating in Mode 1 at 83% power, the neutron flux /

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distribution exceeded the 15% axial' flux difference target band. Since the

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power distribution was brought back inside the target band in 2 minutes, the

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health and safety of publir were not affected. The applicable T.S. is 3.2.1,

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and the event is reportable pursuant to T.S. 6.9.1.9.b.

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CAUSE

CAUSE COMP.

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CODE CODE SUBCCDE COMPONENT CODE SUBCODE SUBCODE

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/R/C/ (11) /X/ (12). /X/ (13) /Z/Z/Z/Z/Z/Z/-(14) g/ (15)

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SEQUENTIAL OCCURRENCE REPORT REVISION i

LER/R0 EVENT YEAR REPORT NO.

CODE TYPE NO,

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1 ACTION FUTURE EFFECT SHUTDOWN ATTACHMENT NPRD-4 PRIME COMP. COMPONENT TAKEN ACTION ON PLANT METHOD HOURS SUBMITTED FORM SUB. SUPPLIER MANUFACTURER

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[X/ (18) LZ/ (19) /Z/ (20) /Z/ (21) /0/0/0/0/ (22) /Y/ (23) /N/ (24) /N/ (25) /W/1/2/0/ (26) :

CAUSE DESCRIPTION AND CORRECTIVE ACTIONS (27)

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The transgression of the axial flux difference target band is attributed to a /

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xenon transient. The corrective action was to insert control rods thereby

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causing the flux distribution to shift cownward.

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FACILITY METHOD OF STATUS

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ACTIVITY CONTENT RELEASED OF RELEASE. AMOUNT OF ACTIVITY (35)

LOCATION OF RELEASE (36) l

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3 PERSONNEL EXPOSURES NLdBE - -

TYPE DESCRIPTION (39)

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PERSONNEL INJURIES NUMBER DESCRIPTION (41) t

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LOSS OF OR DA11 ACE TO FACILITY G3)

TYPE

DESCRIPTION

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PUBLICITY ISSUED DESCRIPTION (45)

NRC USE ONLY

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NAME OF IREPARER W. R. CARTWRIGHT PHONE

('03) 894-5151

'80120903/7,

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A Virginia Electric and Power Company.

North Anna Power Station, Unit #1 Attachment: Page 1 of 1 Docket No. 50-338 Report No. LER 80-098/03L-0

Description of Event

7 On November 23, 1980 while operating in Mode 1 at 83% power, the neutron flux distribution exceeded the 15% axial flux difference target band.

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Probable Consequences of Oct.urrence Since the power distrtbution was brought back inside the target band in 2 minutes, the her.lth and safety of the public were not affected.

Cause of Event

The transgression of the axial flux difference target is attributed to a xenon transient.

Immediate Corrective Action

The immediate corrective action was to insert control rods and cause flux distribution to shift downward.

Scheduled Corrective Action

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There are no scheduled corrective actions.

Actions Taken to Prevent Recurrence 4

No further actions are required.

Generic Implications There are no generic implications.

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