05000317/LER-1981-037-03, /03L-0:on 810521,portion of Incore Detectors Found Inoperable.Caused by Computer Failure Upon Installation of Bad Spare Analog Bus Segmentation Card.Technician Instructed in Verification of Core

/03L-0:on 810521,portion of Incore Detectors Found Inoperable.Caused by Computer Failure Upon Installation of Bad Spare Analog Bus Segmentation Card.Technician Instructed in Verification of Core

ML20008G263
Person / Time
Site:	Calvert Cliffs
Issue date:	06/17/1981
From:	Rizzo P, Wenderlich R BALTIMORE GAS & ELECTRIC CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20008G261	List: 05000317/LER-1981-037, Forwards LER 81-037/03L-0 05000317/LER-1981-037-03, /03L-0:on 810521,portion of Incore Detectors Found Inoperable.Caused by Computer Failure Upon Installation of Bad Spare Analog Bus Segmentation Card.Technician Instructed in Verification of Core
References
LER-81-037-03L, LER-81-37-3L, NUDOCS 8107070215
Download: ML20008G263 (2)

LER-1981-037, /03L-0:on 810521,portion of Incore Detectors Found Inoperable.Caused by Computer Failure Upon Installation of Bad Spare Analog Bus Segmentation Card.Technician Instructed in Verification of Core

Event date:
Report date:
3171981037R03 - NRC Website

text

NRC F@CM 366 UM LM3LLnJ NV(eLW/ (gg2MSew (7 77)

LICENSEE EVENT REPORT CONTROLBLOCK: l l

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8 60 61 DOCKET NL'MBER 68 69 EVENT DATE 74 75 REPORT DATE 80 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h Io Iai I Durino normal oower operation at 1640, determined that due to a computer I

io iai I problem, a portion of the incore detectors were inoperable (T.S. 3.3.3.2).

I l o 141 i The computer problem was corrected and the incore detectors were restor-l lo Isi I ed to full operability at 1930. All excore detectors and the remaining l

lo le 1 I incore detectors were operable during this event. Similar events: none.

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'- 40 41 42 43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h Ii io l I The comouter failed upon installation of a bad spare Analog Bus Segmenta-I mI tion Card (Westinghouse #1 ABS 4) durino troubleshooting of an unrelated i

ii,2i i problem.

Proper incore detector readings were not verified upon comple-l istail tion of shift work. Computer Technicians have been instructed in proper l

gi means of verifying incore detector channel operations.

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81-37/3L DOCKET NO.

50-317 LICENSE NO.

DPR-53 EVENT DATE 05-21-81 REPORT DATE 06-17-81 ATTACHMENT CAUSE DESCRIPTION AND CORRECTIVE ACTIONS (CONT'D)

During the shift prior to the event, a Computer Technician had been performing a routine preventive maintenance procedure to verify proper operation of Incore Instrumentation (ICI) computer channels. Having noted a minor out of tolerance condition for an ICI-low by 9 mvde, the Technician initiated a Maintenance Request to troubleshoot the problem.

Believing the problem to be in relay on one Analog Bus Segmentation Card (Westinghouse Type LABS 4), the Technician installed a spare card and saw no change in the out of tolerance reading. At this time, near the end of his shift, the Technician also verified the apparent proper operation of the computer at the control console. No status lights nor alarms gave indication of a failure. The Technician ended his shift, and approximately one-half hour later the eveat occurred upon the run of a routine program.

Troubleshooting revealed the malfunction of the spare l ABS 4 card which had caused improper readout for about half the ICI's. This card was replaced, and ICI readings were verified operational.

To~ preclude recurrence, Computer Technicians have been instructed in a method to verify proper computer ICI analog operation at the end of each work period. The instructions included methods of verifying other sensitive computer analog functions.

Technicians are instructed to report the results of these checks to the Senior Control Room Operator. -