ML20087C491

Final Significant Deficiency Rept 129 Re Agastat CR0095 Relay Socket Failures.Defective Sockets Replaced W/Agastat CR002 Sockets,Correcting Any Adverse Safety Implications Induced by Socket Failure

ML20087C491
Person / Time
Site:	Limerick
Issue date:	02/17/1984
From:	Kemper J PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
129, NUDOCS 8403130084
Download: ML20087C491 (3)

Text

--_ - ----

-A 2840526000 PHILADELPHIA ELECTRIC COMPANY 2301 M ARKET STREET P.O. BOX 8699 PHILADELPHI A. PA.19101 msie4i-4so2 FEB 171984 V IC E-PR ESID E NT SIGiases svens aseo sessamecos Mr. Thomas E. Murley, Director United States Nuclear Regulatory Commission Office of Inspection and Enforcement, Region I $C-372_

631 Park Avenue King of Prussia, PA 19406

SUBJECT:

Significant Deficiency Report Final Report on Agastat CR0095 Relay Socket Failures Limerick Generating Station, Units 1 and 2 i NRC Construction Permits Nos. CPPR-106 & 107

REFERENCES:

Telecon of January 18, 1984 P. K. Pavlides (PECo) to R. Keimig (USNRC)

FILE: QUAL 2-10-2 (SDR #129)

Dear Mr. Murley:

In compliance with 10CFR50.55 (e), enclosed is the final report on the subject deficiency.

Sincerely, b i Copy to: Director of Inspection and f ce ent United States Nuclear Regulatory Commission Washington, DC 20555 S. K. Chaudhary, Residency NRC Inspector (Limerick)

J. Wiggins, Resident NRC Inspector (Limerick)

DJC:sjb SB2384M1040 Enclosure 8403130084 840217 PDR ADOCK 05000352 S PDR 1

1 t \ 1

.- 'A Signifier.nt Daficiency RJport - No. 129 Agastat CR0095 Relay Socket Failures Limerick Generation Station - Unjtn 1 & 2 Description of Deficiency Recent testing at Limerick Generating Station has revealed a significant number of defective Agastat CR0095 relay sockets.

These sockets are being tested to det. ermine if the design defects described by General Electric (GE) Service Information Letter (SIL) 384 (October 1982) , and NRC IE Information Notice 82-48 (December 3,1982) exist at Linerick.

-The defects are associated with inadequate retention of the female terminal in the relay socket allowing the terminals to be pushed-out of the socket when the relay is plugged-in. This results in an open circuit or a poor connection between the relay and the socket. Approximately 1C% of the sockets tested thus far have

, had this defective condition and PECo has determined that these failures are a significant deficiency that should be reported under 10CFR50. 55 (e) .

Inspection A comprehensive inspection program was developed for Limerick in response to SIL 384 and IE Info Notice 82-48. The program was assigned to PECo Field Engineering Section on September 22, 1983. The program includes approximately 780 relay sockets in GE panels located mostly in the Control Room and Auxiliary Equipment Room. An investigation showed that only the GE portion of the Limerick design utilizes this type of socket. The program did not include any suckets that GE previously inspected or replaced with a modified socket. The test procedure being used is that which - is reconnended in sib 384. Sockets are determined to be defective if any one of the sixteen (15) ~ female terminals in the socket can be pushed-out through the back of the socket by a measured mechanical force (approximately 6 lbs.) . As of

-January 17, 1984, 616 sockets have been inspected; 64 have been focnd defective and steplaced. It was determined that this number of defective sockets presents a potentially reportable item and was reported via telecon to the hRC on January 18, 1984.

-___ _ ___-____ _ _ ___~

,- s s -

2840526000 2-I Corrective Action

.The program ~ is continuing. As defective sockets are discovered,- PECo Field Engineering removes the socket and replaces it with an Agastat CR0002 socket which is functionally identical btit not susceptable to the failure mode described in GE SIL 384. This program will be completed prior to fuel load.

Safety Implications Defective sockets have ' been found in Reactor Protection System (RPS), Emergency Core Cooling System (ECCS), and Nuclear Steam Supply Shutoff System (NSSSS) circuitry. Sockat failures could result in failure of the associated system to perform as

designed.. The defective sockets are being - replaced thus correcting any adverse safety implications induced by the defective socket failure.

f.

-Analysis of Correctivt. Action Replacement of the defective sockets positively assures that the old Lsocket failure will not induce any adverse safety implications.

9

.a- . w ou,.