ML20040F358

LER 82-002/03L-0:on 820103,radiation Detector RE2007 on Safety Features Actuation Sys Channel 4 Failed Low.Low Radiation Bistable Tripped & Alarmed.Caused by Fabrication Error in Attaching Shortened Cable Wire

ML20040F358
Person / Time
Site:	Davis Besse
Issue date:	02/01/1982
From:	Eldred D TOLEDO EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20040F329	List: ML20040F328 ML20040F358
References
LER-82-002-03L, LER-82-2-3L, NUDOCS 8202090111
Download: ML20040F358 (2)

Text

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60 69 61 DOCKET NUMBER 68 EVENT DATE 74 75 REPORT DATE 80 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h j o l 2 l l (NP-33-82-01) On January 3, 1982 at 0137 hours0.00159 days <br />0.0381 hours <br />2.265212e-4 weeks <br />5.21285e-5 months <br />, Radiation Detector RE2007 on Safety I g l Features Actuation System (SFAS) Channel 4 failed low. The low radiation bistable l l o l 4 l l tripped and gave an alarm to the Control Room operators. Per Technical Specificationi o 3 l 3.3.2.1, Act' ion (b), the high radiation bistable BA401 was tripped. There was no l o o l danger to the health and safety of the public or station personnel. There was no j g l reduction in power. The three redundant radiation monitors were in operation at the l 1 o 18 I I time. l

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36 37 40 44 42 43 I44 z 1919191@ 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS 21 l i l o l l The cause was a fabrication error in attaching the cable wire to the connector at the1 i i l detector. One of the seven wires in the cable at the connector was annroximatelv i

, l 3/16" shorter than the others. The short wire was taking the strain and eventually l lil3l l broke. Under MWO-IC-100-82 the connector was properly re-attached with all wires cutI i 4 l to the required length. System was restored to operability at 1500 hours0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br /> on 1/7/82. I 7 8 9 RO

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TOLED0' EDISON COMPANY DAVIS-BESSE NUCLEAR POWER STATION UNIT ONE SUPPLEMENTAL INFORMATION FOR LER NP-33-82-01 DATE OF EVENT: January 3, 1982 FACILITY: Davis-Besse Unit 1 IDENTIFICATION OF OCCURRENCE: Radiation Detector RE2007 in Safety Features Actua-tion System (SFAS) Channel 4 failed low.

Conditions Prior to Occurrence: The unit was in Mode 1 with Power (MWT) = 2460 and Load (Gross MWE) = 830 Description of Occurrence: At 0137 hours0.00159 days <br />0.0381 hours <br />2.265212e-4 weeks <br />5.21285e-5 months <br /> on January 3, 1982, RE2007 on SFAS Channel 4 failed low. The low radiation bistable tripped and gave an alarm to the operators. Per Technical Specification 3.3.2.1, Action (b), the high radiation bistable BA401 was tripped. This placed the SFAS in a one out of three trip condi-tion. There was no power reduction as a result of this occurrence.

Deatgnation of Apparerat Cause of Occurrence: This occurrence can be attributed to a fabrication error in the connecting of the cabic wires to the connector at the detector. One of the seven wires at the connector was approximately 3/16 inch shorter than the others. Consequently, It was taking all of the strain of the cable. This single wire eventually broke due to unequal distribution of force applied to it (connection had been in service for a period in excess of one year) .

Analysis of Occurrence: There was no danger to the health and safety of the public or station personnel. There were three redundant monitors in operation.

Corrective Action: The cable was reconnected to the connector with all wires cut 1 to the required length, thus dintributing the strain on the individual wires squarely.

A new detector was calibrated and the system was returned to service at 1500 hours0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br /> on January 7, 1982.

Failure Data: No previous failures of this type have been reported.

LER #82-002 t'

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