ML19350D798

LER 81-034/03L-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

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: ML19350D796 ML19350D798
References
LER-81-034-03L, LER-81-34-3L, NUDOCS 8105190326
Download: ML19350D798 (2)

Text

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U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT CONTROL BLOCK / / / / / / / (1) (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION)

/0/1/ /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)

/0/2/ / On April 18, 1981, during Mode 1 operation the Axial Power Disbribution Moni- /

/0/3/ / toring System (APDMS) did not print-out the results of the Fj(z) scan for a /

/0/4/ / 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 /

/0/5/ / received during this period. Since the control rods were above the insertion /

/0/6/ / limits and delta flux was within the limit at all times, there was no effect /

/0/7/ / on the health and safety of the public. This event was contrary to T.S. 3.2.6 /

/0/8/ / and reportable pursuant to T.S. 6.9.1.9.c. /

SYSTEM CAUSE CAUSE COMP. VALVE CODE CODE SUBCODE COMPONENT CODE SUBCODE SUBCODE

/0/9/ /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 /8/1/ [-/ /0/3/4/ [_\_/ /0/3/ [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)

/1/0/ / The cause of the malfunction was a failure of the printer in the APDMS. A /

/1/1/ / manual scan of axial power distribution via periodic test 26.3 was conducted /

/1/2/ / with no indication of high Fj(z). The APDMS printer was repaired and /

/1/3/ / subsequently proven to be operable. /

/1/4/ / /

FACILITY METHOD OF STATUS %P0kIR DISCOVERY DESCRIPTION (32)

OTHER STATUS ,30) DISCOVERY

/1/5/ [/ (28) /1/0/0/ (29) / NA /' [B/ (31) / OBSERVATION /

ACTIVITY CONTENT RELEASED OF RELEASE AMOUNT OF ACTIVITY (35) LOCATION OF RELEASE (36)

/1/6/ [Z/ (33) LZ/ (34) / NA / / NA /

DERSONNEL EXPOSURES NUMBER TYPE DESCRIPTION (39)

/1/7/ /0/0/0/ (37) [Z[ (38) / NA /

PERSONNEL INJURIES NUMBER DESCRIPTION (41)

/1/8/ /0/0/0/ (40) / NA /

LOSS TYPE OF OR DAMAGE TO FACILITY ( )

DESCRIPTION

/1/9/ [Z[ (42) / NA /

PUBLICITY ISSUED DESCRIPTION (45) NRC USE ONLY

/2/0/ [N[ (44) / NA /////////////

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. [

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. 1 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. l i

Actions Taken to Prevent Recurrence  ;

l The printer was replaced and subsequently proven operable.

Generic Implications There are no generic implications. .

l 9

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