ML20134B502
Text
i CC jf).3W oggg EVDU TRACKItG SHEET Plant:
Si-L UC t E.
Unit:
I Engineer:
T* M D Event: b!Ic./13 Homing Report:
/
/
Briefing:
,50.72#:
LER8:
PNW:
Other Notification:
^
Syctera:
EMITREOC-.
Component:
26L OYf>
Event Description INSULGTid N Fe /LuR E iN PEdTEATh/G.
tE.LA41r\\rb.
1 i
POER SIGNIFICANCE 1 - Operation at
% of Power A - Reactor Protection System 2 - Startup at
% of Power B - Safety-Belated Cooling System 3 - Hot Standby C - Fuel Cladding
- Hot Shutdown D - Reactor Coolant Pressure B:endarf 5
Cold Shutdown E - Containrent 6 - Refueling F - Plant Power 7 - OGer G - Unexpected Plant Perfomance H - Other CAUSE 01-Eeuirmentraiture Evan rePE 2 - Design or Installation Error 3 - Cterating Error S
- Significant Event 4 - Maintenance Error Event of Interest 5 - Other OTR - Other POTDUIAL A0 Yes / o Criterion:
Preposed by:
3 /15/9 4
-ineer Approved:
O
/
/
Section G ader
/
/
Branch Chief h3 a H 6 NRC FILE CENTER COPY pt EVDES ASSESSMDTT PANEL First Screening:
/
/
Closure:
/
/_
t-i t'9 7 F}
288a.trk how@ P x&
EVENT F0ll0W-UP ASSIGNMENT SHEET ASSIGNMENT DATE: April 16, 1993 ASSIGNED T0: KOSHY PLANT & UNIT: ST. LUCIE 1 EVENT DATE: April 16, 1993 50.72 REPORT N0:
DAILY REPORT DATE:
0THER REPORT: ORAL FROM PM EVENT
SUMMARY
AND SPECIFIC FOLLOW-UP ASSIGNMENT SAFETY GRADE RELAYS IN0PERABLE DUE TO GUNK FROM INSULATION PLASTICIZER; SEE I/N 91-20 FOR CAUSE.
FOLLOW UP FOR SAFETY SIGNIFICANCE AND GENERIC IMPLICATIONS.
PREPARE I/N SUPP IF APPROPRIATE.
SAFETY SIGNIFICANCE:
SIGEVENT A0 OTHER __E 0 I OR BRIEFING:
CLOSE0VT The over-current relays failed the surveillance test because of a coating of green substance on the contacts.
This substance originated from the internal wiring insulation.
This wiring is part of the relay assembly and it had 1970 date code.
Unit 2 relays with date code 1975 were free from this problem.
This failure appears to be from a slowly developing insulation degradation that could be recognized through periodic inspection or surveillance.
The event was classified as E0I.
An information notice is being processed due to generic implications. A draft copy is attached.
G:
Efo4%M "-
O UNITED STATES NUCLEAR REGULATORY C0f911SSION OFFICE OF NUCLEAR REACTOR REGULATION WASHINGTON, D.C.
20555 February XX, 1994 NRC INFORMATION NOTICE 94-XX:
FAILURE OF AN ASEA BROWN B0 VERI / WESTINGHOUSE OVERCURRENT PROTECTIVE RELAY DUE TO ELECTRICAL WIRE INSULATION DEGRADATION Addressees All holders of operating licenses or construction permits for nuclear power reactors.
Puroose The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to alert addressees of a possible situation where electrical wire insulation degradation may cause failure of Asea Brown Boveri (ABB)/ Westinghouse protective relays.
It is expected that recipients will review the information for applicability to their facilities and consider actions, as appropriate, to avoid similar problems. However, suggestions contained in this information notice are not NRC requirements; therefore, no specific action or written response is required.
Description of Circumstances On April 14, 1993, at St. Lucie Unit 1 a non-safety related ABB/ Westinghouse model 00-9 overcurrent protective relay failed to operate during calibration testing.
The relay's instantaneous trip unit was coated with a green substance. The green substance was coming from the relay's internal wiring.
Electrical tests indicated that the substance was insulating the relay's instantaneous contacts and prevented relay operation even at twice the normal trip current.
The relay's internal wiring was manufactured by Philadelphia Insulated Wire and had polyvinylchloride (PVC) insulation. The wiring was black with white lettering which identified it as 105*C, 18 AWG, manufactured by the Philadelphia Insulated Wire Co.
The licensee also inspected all ABB/ Westinghouse protective relays and found many of the relays contaminated with the green substance.
The relays in which the PVC wiring was identified were ABB/ Westinghouse models 00-7, C0-9, KC-4, COM-5, CV-2, and CVE. Most Unit I relays which had the green substance contamination had 1970 date codes.
The licensee rewired or replaced all relays which had the PVC insulated internal wiring.
Discussion l
The licensee performed a laboratory analysis and identified the green substance as a copper chelate of the polyester plasticizer from the PVC insulation on the relay internal wiring.
j
=
- - =
O IN 94-XX february XX, 1994 Page 2 of 2 4
Wiring of the 14 AWG and 18 AWG sizes with the copper chelate contamination, manufactured by Philadelphia Insulated Wire Co., was identified within the i
AB8/ Westinghouse relays.
The replacement wiring had cross linked polyethylene insulation. The licensee also replaced the relay coils because the coil lead wiring was not identifiable and could have been PVC insulated.
The Unit 2 relays were inspected and many had PVC insulated internal wiring.
No evidence was found of any copper chelate contamination.
Most Unit 2 relays had 1975 date codes and had less time in service than the Unit I relays.
This indicated that the PVC breakdown phenomena was likely time dependent. The laboratory evaluation also indicated that overheating of the wiring could have caused the release of the plasticizer.
This information notice requires no specific action or Written response.
If you have any questions about the information in this notice *, please contact 1
one of the technical contacts listed below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager.
Brian K. Grimes, Director Division of Operating Reactor Support Office of Nuclear Reactor Regulation Technical contacts:
G. MacDonald, RII (404) 331-5576 M. Shymlock, RII (404) 331-5596
Attachment:
l
//
list of Recently Issued NRC Information Notices hMntflu M
OGCB: DORS E[
E EEL TJKim CBerljnger Hod s 02/08/94' 9e
/94
/4 02/////94 02/g 4
/
)
DORSk Tech Ed 0GCB:00RS DORS:NRR W~ MT ffee AKugler BKGrimes Or 02/' //94 02/08/94 02/ /94 02/ /94