05000339/LER-1981-034-03, /03L-0:on 810418,during Mode 1 Operation,Axial Power Distribution Monitoring Sys Did Not Print Out Results of Fj(Z) Scan.Caused by Failure of Printer.Printer Repaired

/03L-0:on 810418,during Mode 1 Operation,Axial Power Distribution Monitoring Sys Did Not Print Out Results of Fj(Z) Scan.Caused by Failure of Printer.Printer Repaired

ML19350D798
Person / Time
Site:	North Anna
Issue date:	05/13/1981
From:	Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19350D797	List: 05000339/LER-1981-034, Forwards LER 81-034/03L-0 05000339/LER-1981-034-03, /03L-0:on 810418,during Mode 1 Operation,Axial Power Distribution Monitoring Sys Did Not Print Out Results of Fj(Z) Scan.Caused by Failure of Printer.Printer Repaired
References
LER-81-034-03L, LER-81-34-3L, NUDOCS 8105190326
Download: ML19350D798 (2)

LER-1981-034, /03L-0:on 810418,during Mode 1 Operation,Axial Power Distribution Monitoring Sys Did Not Print Out Results of Fj(Z) Scan.Caused by Failure of Printer.Printer Repaired

Event date:
Report date:
3391981034R03 - NRC Website

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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/2/ (2)

/0/0/-/0/0/0/0/0/-/0/0/ (3)

/4/1/1/1/1/ (4)

/ / / (5)

LICENSEE CODE LICENSE NUMBER LICENSE TYPE CAT

/0/1/

REPOR [L/ (6)

/0/5/0/0/0/3/3/9/ (7)

/0/4/1/8/8/1/

(8) /0 5 A /3 /;B /1/ (9)

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

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On April 18, 1981, during Mode 1 operation the Axial Power Disbribution Moni- /

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toring System (APDMS) did not print-out the results of the Fj(z) scan for a

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period of 19 hours2.199074e-4 days <br />0.00528 hours <br />3.141534e-5 weeks <br />7.2295e-6 months <br /> and 16 minutes. No F(z) or APDMS malfunction alarms were

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received during this period.

Since the control rods were above the insertion /

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limits and delta flux was within the limit at all times, there was no effect

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on the health and safety of the public. This event was contrary to T.S. 3.2.6 /

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and reportable pursuant to T.S. 6.9.1.9.c.

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SYSTEM

CAUSE

CAUSE COMP.

VALVE CODE CODE SUBCODE COMPONENT CODE SUBCODE SUBCODE

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/R/C/ (11) [E/ (12) [G/ (13) /Z/Z/Z/Z/Z/Z/ (14) LZ/ (15)

LZ/ (16)

SEQUENTIAL OCCURRENCE REPORT REVISION LER/R0 EVENT YEAR REPORT NO.

CODE TYPE NO.

(17) REPORT NUMBER

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[_\\_/

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[L/

[;/

[0/

ACTION FUTURE EFFECT SHUTDOWN ATTACHMENT NPRD-4 PRIME COMP.

COMP 0hTNT TAKEN ACTION ON PLANT METHOD HOURS SUBMITTED FORM SUB. SUPPLIER MNIUFACTURER [X/ (18) [Z/ (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 cause of the malfunction was a failure of the printer in the APDMS. A

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manual scan of axial power distribution via periodic test 26.3 was conducted

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with no indication of high Fj(z). The APDMS printer was repaired and

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subsequently proven to be operable.

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FACILITY METHOD OF STATUS

%P0kIR OTHER STATUS,30) DISCOVERY DISCOVERY DESCRIPTION (32)

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[/ (28)

/1/0/0/ (29) /

NA

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[B/ (31)

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OBSERVATION

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ACTIVITY CONTENT RELEASED OF RELEASE AMOUNT OF ACTIVITY (35)

LOCATION OF RELEASE (36)

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[Z/ (33)

LZ/ (34) /

NA

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NA

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DERSONNEL EXPOSURES NUMBER TYPE DESCRIPTION (39)

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NA

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PERSONNEL INJURIES NUMBER DESCRIPTION (41)

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NA

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LOSS OF OR DAMAGE TO FACILITY ( )

TYPE

DESCRIPTION

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NA

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PUBLICITY ISSUED DESCRIPTION (45)

NRC USE ONLY

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NAME OF PREPARER W. R. CARTWRIGHT PHONE (703) 894-3151 18'10 519 0 *cMo

3.

l Virginia Electric and Power Company North Anna Power Station, Unit #2 Attachment: Page 1 of 1 Docket No. 50-339 Report No. LER 81-034/03L-0

Description of Event

On April 18,1981 at 1:45 a.m. during Mode 1 operation at 100% power, l

it was noted that the APDMS had not printed the results of the two previous 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> automatic scans. The control rods had been moved greater than 5 steps about one and one-half hours prior to this time. This would normally cause the scan intervals to reduce to 30, 60, 90, 120, 240 and finally 480 l

minutes. However, when examined by the control room operators, there was no print-out for this cycle nor for the previous 2 eight hour cycles.

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l Probable Consequences of Occurrence I

j The APDMS functions automatically to monitor axial flux distribution to ensure that the core heat flux hot channel factor remains within limits.

Since the control rods were above the insertion limits and the delta flux limit had not been exceeded while above 90% of rated thermal power, the health and safety of the public were not affected.

Cause of Event

.The cause of the malfunction was a failure of the printer in the APDMS cabinet.

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Immediate Corrective Action

A manual scan of axial flux distribution was cceducted by performing PT-26.3.

The results of this scan were satisfactory.

Scheduled Correct'ive Action 1

There is no scheduled corrective action.

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Actions Taken to Prevent Recurrence l

The printer was replaced and subsequently proven operable.

Generic Implications There are no generic implications.

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