ML18347B181

License Event Report 1978-007-00 Relates to Electrical Connectors Inside of Containment

ML18347B181
Person / Time
Site:	Palisades
Issue date:	03/27/1978
From:	Hoffman D Consumers Power Co
To:	James Keppler NRC/RGN-III
References
LER 1978-007-00
Download: ML18347B181 (3)

Text

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..... consumers Power company

• General Offices: Zl2 West Michigan Avenue, Jackson, Michigan 49201

• Area Code 517 788-0550 March 27, 1978 Mr James G Keppler Office of Inspection and Enforcement Region III US Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137 DOCIIBT 50-255 -LICENSE DPR-20 -PALISADES PLANT -ER-78-007 The attached Palisades Plant Licensee Event Report 78-007 relates to electrical connectors inside of containment and is reportable under Technical Specification 6.9.2.a(a).

David P Hoffman Assistant Nuclear Licensing Administrator CC: Director, Office of Nuclear Reactor Regulation Director, Office of Inspection and Enforcement 2 9 1978

• Palisades NRC FORM 366 (7-771 U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT CONTROL BLOCK: I 10 (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) 1 6 1 a IM I I Ip I A IL 11 101 0 I 0 I 0 I 0 I 0 I 0 I 0 I 0 I 0 I 0 I 0 !014 1111 11 11 101 I 10 9 LICENSEE CODE 14 LICENSE NUMBER 25 26 LICENSE TYPE 30 57 CAT 58 CON'T WJJ 1 a o I 5 I o I o I o I 2 I 5 I 5 101 o I 3 I 1 I 1 I 1 I s I© I o I 3 I 2 I 1 I 1 I 8 10 60 61 DOCKET NUMBER 68 69 EVENT DATE 74 75 REPORT DATE 80 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES@

I During sealing of electrical connectors located inside containment, it !]JI] I was found. that sockets and/ or sealing plugs were missing from several CQ:GJ connectors which supply power to components required to be operable during! [§]]] a DBA. The missing parts result in a path which could permit moisture [Q]]J to enter a connector and cause a short across its pins, thereby possibly [IJI] preventing its associated component from functioning as required during []]]] I an accident.

See attachment for listing of connectors and components.

I a 9 so SYSTEM CAUSE CAUSE COMP. VALVE CODE CODE SUBCODE COMPONENT CODE SUBCODE SUBCODE mII IXIXI@ w@ 1x1x1x1x1x1x1@

1z1@ 1 a 9 10 1 1 12 13 18 19 20 SEQUENTIAL OCCURRENCE REPORT REPORT NO. CODE TYPE I I 1010111

• 10111 W l=l 23 24 26 27 28 29 30 31 (.':;'\ LERIRO CVENTYEAR VJ REPORT I 7 I 8 I NUMBER 21 22 REVISION NO. w 32 ACTION FUTURE EFFECT SHUTDOWN C::::.. ATTACHMENT NPRD-4 PRIME C.OMP. TAKEN ACTION ON PLANT METHOD HOURS SUBMITTED FORM SUB, SUPPLIER COMPONENT MANUFACTURER W@W W@ Llli 101010101 L.1.J@ W l!_J@) 33 34 35 36 37 40 41 42 43 Iv 11 121 o I@ CAUSE DESCRIPTION AND CORRECTIVE ACTIONS @ 44 47 I Wiring of the connectors during initial plant construction was performed IJII] I without ensuring that all holes in the connectors were filled. This 1II1J apparently resulted from inadequate wiring procedures combined with IJJI] I insufficient quality control. The connectors will be sealed with potting !Im I compound prior to resumption of power operations.

1 a 9 FACILITY rJQ\ STATUS % POWER OTHER STATUS METHOD OF (.;:;\ 80 [ili] LQ.J@ I o I o I o l@l.___N....;./_A

___ ____. DISCOVERY DISCOVERY DESCRIPTION 0 9 10 12 13 44 ACTIVITY CONTENT {.;;;\ RELEASEO OF RELEASE I AMOUNT OF ACTIVITY NA I a 9 10 11 44 45 46 BO N/A LOCATION OF RELEASE@ 45 80 PERSONNEL EXPOSURES r.;;:;., NUMBER (.;:;\TYPE OESCRIPTION

[Q2J JO IO IO 1 a 9 11 12 13 80 PERSONNEL INJURIES NUMBER DESCRIP7ION6

[QI] 10 I 010 7 8 9 11 12 80 LOSS OR DAMAGE TO FACILITY 143' TYPE DESCRIPTION

\'.'.,;/ 7 8 9 10 so PUBLICITY Q.. R SE 0 *1ssUEDQ DESCRIPT19N N c u NL y [ill] l1I..J6 __ N_1_A ___________________

__, I I I 11 11 11 I I I I a 9 , o 68 69 80 Attachment to LER Consumers Power Company Palisades Nuclear Plant Docket 050-255 Background/Discussion

-During the refueling outage which commenced on January 6, 1978, the decision was made to seal certain electrical connectors with potting compound, in order to provide a greater degree of assurance that they would function normally in the event of a Design Basis Accident (DBA). The connectors chosen were those supplying electrical power to components and instruments which are required to be operable during a DBA. During the potting process, several connectors were found to be deficient in that they contained socket locations which were not sealed. This condition results in a path which permits moisture to pass through the _connector and thereby could short the circuits associated with the connector.

Connectors Affected -A total of thirteen connectors were deficient.

They were furnished by Viking Industries and were the twelve or nineteen pin variety. Sealing of the connectors at socket locations is normally accomplished by a very tight fit at the point the conductor jacket mates with the connector body. The deficient connectors were missing conductors.

Components Affected -As a result of the deficient connectors, the components listed below might not have been able to perform under post-LOCA conditions:

MO 3008 -Loop lA Low-Pressure Safety Injection (LPSI) motor-operated valve (MOV) MO 3010 -Loop lB LPSI MOV MO 3007 -Loop lA High-Pressure Safety Injection (HPSI) MOV MO 3009 -Loop lB HPSI MOV MO 3013 -Loop 2B HPSI MOV MO 3062 -Loop 2B HPSI MOV (Redundant Path) MO 3064 -Loop 2A HPSI MOV (Redundant Path) MO 3066 -Loop lB Ii-PSI MOV (Redundant Path) MO 3068 -Loop lA HPSI MOV (Redundant Path) SV 2113 -Loop lA Charging Distribution Stop Valve PT 0751A/PT0751C/PT0752A/PT0752C

-Steam Generator Pressure Transmitter PT 0102A/PT0102C

-Pressurizer Pressure Transmitter Cause -The most probable causes of this condition appear to be inadequate procedures for wiring the connectors, combined with insufficient controls over the installation process during initial plant construction.

Corrective Action -The connectors will be sealed with a potting compound which has been demonstrated to withstand the LOCA environment.

The repair will be c*ompleted prior to resumption of power operations.

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