ML19308D137

RO-77-54:on 770601,control Rod Drive Sys Failed to Position Regulating Rods Per Auto Demand.Caused by Loose Printed Circuit Card Connector in Rod Drive Programmer.Connector Repaired

ML19308D137
Person / Time
Site:	Crystal River
Issue date:	06/22/1977
From:	Stewart W FLORIDA POWER CORP.
To:
Shared Package
ML19308D112	List: ML19308D111 ML19308D137
References
NUDOCS 8002270617
Download: ML19308D137 (2)

Text

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Q l demand contrary to Technical Specification 3.1.3.1. Redundancv was maintained by manual a 7 OU

• l 3l l control. This event was not repetitive. Repairs to the auto ' rod control syst m vara

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]Q l effected and the system restored operable.

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7 89 10 11 12 17 43 44 47 48 5 CAUSE DESCDIPTION h /'

o l This event was caused by a loose connector on a CRD programmer printed circuit card.

i 7 89 gg l The connector was repaired and restored operable.

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Facilit y METHOo CF Status  % PoWE A CTHER STATUS CisCQVERY DISCOVERY CEScAt" TON 1

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SUPPLEMENTARY INFORMATION

(,s _-~~/ 1. Report No. :- 50-302/77-54 s

2. Facility: Crystal River Unit #3 .

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3. Report Date: 22 June 1977

4. Occurrence Date: 1 June 1977

5. Identification of occurrence:

Failure of Control Rod Drive System to position regulating rods as per auto demand contrary to Technical Specification 3.1.3.1.

6. Conditicas Prior to Occurrence:

Mode 1 operation increasing load.

7. Description of Occurrence:

At 0535 while increasing load to 92% the automatic rod control failed to respond 7 to a transient neutron error causing reactor power to exceed the power cutoff level. .

The rod control system was placed in manual. control and power was reduced from "

approximately 95% to 92%'. When again placed in automatic control CRD system inter-mittently faile.d to respond per demand. The rod control system was placed in auxiliary power and manual mode of operation. Investigation revealed that there

~s was a loose connector on a printed circuit card of the CRD programmer. Repairs were effected and the system restored operable'. .

l 8. Designation of Apparent Cause: .

] These occurrences were caused by a loose printed circuit . card connector in the l CRD programmer. ,

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9. Analysis of Occurrence:

t There were no safety implications as the CRD. system was manually controlled.

10. Corrective Action: -

The loose connector on the .P.C. card was repaired and the reamining P.C. card

connectors were checked and verified satisfactory.

11. Failure Data:

)

These events constitute the first occurrence of this type.

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