05000317/LER-1979-002-03, /03L-0 on 790208:plant Computer Failed,Causing Loss of Control Element Assembly Pulse Counting Circuit Indication;Failed Again on 790212.Caused by Problem W/Power Supply Connections

/03L-0 on 790208:plant Computer Failed,Causing Loss of Control Element Assembly Pulse Counting Circuit Indication;Failed Again on 790212.Caused by Problem W/Power Supply Connections

ML19259B496
Person / Time
Site:	Calvert Cliffs
Issue date:	02/22/1979
From:	Davis S, Romney K BALTIMORE GAS & ELECTRIC CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19259B495	List: 05000317/LER-1979-002, Forwards LER 79-002/03L-0 05000317/LER-1979-002-03, /03L-0 on 790208:plant Computer Failed,Causing Loss of Control Element Assembly Pulse Counting Circuit Indication;Failed Again on 790212.Caused by Problem W/Power Supply Connections
References
LER-79-002-03L, LER-79-2-3L, NUDOCS 7902260422
Download: ML19259B496 (2)

LER-1979-002, /03L-0 on 790208:plant Computer Failed,Causing Loss of Control Element Assembly Pulse Counting Circuit Indication;Failed Again on 790212.Caused by Problem W/Power Supply Connections

Event date:
Report date:
3171979002R03 - NRC Website

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6 U. S. NUCLE AR REGUL ATORY COMMISSION 17-7 7)

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LICENSEE EVENT REPORT h

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60 61 DOCKET NUMBER 68 69 EVENT DATE 74 75 REPORT DATE 80 EVENT DESCRIPTION AND PROBABLE CONJEOUENCES h l At 0800 the plant computer failed causina a loss of control element assembly I

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l(CEA) pulse counting circuit indication and incore detection system required l

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l o 14 j lby T.S. 3.1.3.3.d and T.S. 3.3.2, respectively.

Reactor power was reduced to l

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O s 1 81% at 1705 to satisfy the requirement of T.S. 3.2.1.

A procedure was initiated I

lat 1900 to monitor CEA pulse cot-Linn indication in the cable spreadina room to 1

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l satisfy T.S. 3.1.3.3.d.

The computer was returned to service at 1340 on 2/9/79.

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7 At 1300 on 2-12-79 the plant computer again failed causing a loss of control (CONT)

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33 35 36 31 40 41 42 43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS i

o i In consultation with the ecuinment vendor the Read Amplifier Card was replaced.

I li li l I Power was annlied and the system restarted with no apparent problems and no loss I

i 2 lof stored data.

At the second failure the vendor indicated a problem with the l

3 a l power supply connections. The connections were cleaned and tiahtened. The l

I oriainal Read Amplifier Card was reinstalled. The equipment was restarted (CONT)

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7 8 9 10 68 69 80 S. M. Davis /K. M. Romney NAME OF PREFARER PHONE:

4 LER 79 02/3L DOCKET NUMBER 50-317 LICENSE NO. DPR-53 EVENT DATE 02/08/79 REPORT DATE 02/22/79 ATTACHMENT EVENT DESCRIPTION AND PROBABLE CONSEQUENCES (CONT):

element assembly (CEA) pulse counting circuit indication and incore detection system required by T.S. 3.1.3.3.d and T.S. 3.3.3.2, respectively.

A procedure wa: initiated at 1430 to monitor CEA pulse counting indication in the cable spreading room to satisfy T.S. 3.1.3.3.d.

The computer was returned to service at 1730. LER 78-39 (U-1) describes a similar event.

CAUSE & CORRECTIVE ACTIONS (CONTINUED):

with no problems and returned to service. No further corrective action is necessary.