RC-93-0251, Follow-up to 930521 Interim Part 21 Rept SSH 930003 Re Spare Model D26 Type M Relays Mfg by Cutler-Hammer & Supplied by Vitro Corp.All Affected Relays in storage,35 Rejected & Will Not Be Used in Any in-plant Application

Follow-up to 930521 Interim Part 21 Rept SSH 930003 Re Spare Model D26 Type M Relays Mfg by Cutler-Hammer & Supplied by Vitro Corp.All Affected Relays in storage,35 Rejected & Will Not Be Used in Any in-plant Application

ML20057D742
Person / Time
Site:	Summer
Issue date:	09/28/1993
From:	Skolds J SOUTH CAROLINA ELECTRIC & GAS CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-PT21-93 RC-93-0251, RC-93-251, SSH-930003, NUDOCS 9310050287
Download: ML20057D742 (2)

Text

,

-U J hn Sos Sogth Caroline Electric a Gas Company Nuclear Operations

, gngngSC 29065 SCE&G j o scura 'a w, l September 28, 1993 Refer to: RC-93-0251 I I

I i

Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555 Gentlemen:

Subject:

VIRGIL C. SUMMER NUCLEAR STATION (VCSNS) l DOCKET N0. 50/395 OPERATING LICENSE NO. NPF-12 i

FOLLOW-UP TO INTERIM PART 21 REPORT (SSH 930003)

South Carolina Electric & Gas Company (SCE&G) submits this letter as a follow-up to the interim report submitted on May 21, 1993, in accordance with 10 CFR 21.21(a)(2).

On March 23, 1993, Nonconformance Notice (NCN) 4637 was generated when three spare Model D26 Type M relays manufactured by Cutler-Hamer and supplied by Vitro Corporation, formerly known as Automation Industries / Vitro Labs, were found defective.

The Part 21 evaluation for NCN 4637 discussed in the interim report was I completed September 10, 1993, with the determination that a defect exists and i is reportable under 10CFR21. The relay (Model D 26 MR 31A, type M) was supplied as a spare for the Vitro-supplied Emergency Diesel Generator Load Sequencer, but was stored such that it could have been used in other Class IE applications. ,

1 The relay contacts are enclosed in housings constructed partially or completely from General Electric (GE) Lexan (polycarbonate). The Lexan housings were found to have become brittle, cracked or broken such that they would have been unable to perform their intended function.

Investigation found that non-standard packaging used by Vitro was the root cause of the failure. These relays were supplied in sealed airtight packaging and it was determined that the phenolic resin relay housings i generated amonia which, if concentrated, will attack the Lexan (polycarbonate) housing. The same relay, as supplied through Cutler-Hamer, in standard packaging was found to not have this problem as they are not airtight and therefore allow the escape of off-gassing. Vitro does not normally supply Cutler-Hammer relays but did so in response to specifications from V. C. Sumer Nuclear Station.

All.affected relays in storage, thirty-five, have been rejected and will not be used in any in-plant application. Three Cutler-Hammer relays supplied by Vitro were installed in the plant. /, I pi 040nn 9310050287 930928 PDR D b D

S ADDCK 05000395 PDR ha%

t- _

Document Control Desk SSH 930003 Ppge 2 of 2 One relay was installed in the local control switch (fire switch) per Appendix R for "B" chiller. This relay has been replaced. One relay was disassembled and a set of contacts was installed in the ESF Load Sequencer for sequencer control of Emergency Feedwater Motor Driven Pump A. These contacts have been replaced.

The third relay, which has not been replaced, is used in the auto start circuit of non safety related CRDM cooling water pumps. This relay is wired into the CRDM cooling water valve (XVG 7502) control circuit. Thc relay coil is powered by a 1-E circuit but the contacts are wired into the non-1E pump control circuits. This relay will be replaced during the next outage of sufficient duration.

If you require any further information, please contact Mr. R. J. Bouknight at (803) 345-4085.

Very truly yours, John L. Skolds RJB: led c: 0. W. Dixon R. R. Ma'1an R. J. White S. D. Ebneter NRC Resident Inspector J. B. Knotts Jr.

NSRC CFS RTS (SSH 930003)

File (818.18) 1

)

)

l

]