ML20197D437

/03L-0 on 781029:during Refueling,While Reloading Fuel in Vessel W/All Rods inserted,2 IRM Channels Were Inoperable in Same Trip Sys.Irm F Signal Cable Was Sheared by CRD Repair Platform IRM H Signal Cable Disconnected

ML20197D437
Person / Time
Site:	Browns Ferry
Issue date:	11/15/1978
From:	TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML18024A541	List: ML20197D437
References
LER-78-029-03L, LER-78-29-3L, NUDOCS 7811280298
Download: ML20197D437 (2)

Text

l NRC FORM 366 U. S. NUCLE AR REGULATORY COMMISSION

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• LICENSEE EVENT REPORT i 1

CONTROL BLOCK: l l l l l l (PLE ASE PRINT OR TYPE ALL REOUIREO INFORMATION)

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l L l BCODE 'l R lF l 3 l@l0 !O l-UCENSE 14 16 l0 l0 l0 l0 l0 l- l02510 l@l4l1l1l1l1l@l NUMBER 26 LICENSE TYPE JO I

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74 75 REPORT DATE 80 EVE NT DESCRIPTION AND PROB ABLE CONSEOUENCES h 1ol21 lDuring refueling while reloading fuel in the vessel with n11 rods innnrred. two IRM l J

l o l a 1 tchannels were inoperable in the same trip system exceeding the limits of table 3.1. A of j l j

[o l4 l lthe technical specification. Redundant neutron monitoring systems were available and i o g g, ; l operating in the noncoincidence mode. There was no hazard to the public health or l loIsl l safety. l l

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di 42 43 44 di CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h I i l o l IIRM F signal cable was sheared by the CRD reDair platform. IRM H signal cable con- I li 111 Inector became disconnected during maintenance. R3fueline onerations vern halted imH1 l

1 i7j lthe cables were repaired and reconnected. I 1

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STA  % POWER OTHER ST ATUS OlSCO R DISCOVERY DESCRIPTION j IRM downscale indication y Q @ l0l0l0j@l NA l l A l@l l ACTIVITY CO TENT RflE ASED OF RELE ASE AMOUNT OF ACTIVITY LOCATION OF RELE ASE j i l 8sj9 { @ W@l t 10 11 NA 44 l l 45 NA HO l

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LER SUPPLEMENTAL INFORitATION 1 BFRO 296 / 7829 Technical Specification Involved rable 31^ _ _.

l Reported Under Technical Specification 6. 7. 2. b (4) __ j Date of Occurrence 10/29/78 Time of Occurrence 2023 Unit 3 ,

Identification and Description of Occurrence: l During refueling while reloading fuel in the vessel with all rods inserted, two IRM channels were operable in the same trip system.

Conditions Prior to Occurrence:

Loading fuel in the vessel.

Action specified in the Tcchnical Specification Surveillance Requirements met due to inoperable equipment.

i 'es cribe .

The fuel loading was stopped.

Apparent Cause of Occurrence: ,

One IRM was inoperable due to movement of the service platf orm; the second IRM became inoperable by personnel inadvertently damaging the cable while working

! under the reactor pressure veasel.

Analysis of Occurrence:

None Corrective Action:

Repaired cables and reconnected connectors. Refueling resumed af ter a minimum number of IRM channels were returned to service.

Failure Data:

None Tennessee Valley Authority - Br wns Ferry Nuclear Plant