ML19256F706
| ML19256F706 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 12/07/1979 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Goodwin C PORTLAND GENERAL ELECTRIC CO. |
| References | |
| NUDOCS 7912200240 | |
| Download: ML19256F706 (1) | |
Text
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UNITED STATES S
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NUCLEAR REGULATORY COMMISSION o
$ J-REGION V c
1990 N. CALIFORNIA BOULEVARD o, '
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SUIT E 202, WALNUT CREE K PLAZA
%,e WALNUT CREE K, CALIFORNI A 94596 December 7, 1979 Docket 110. 50-344 Portland General Electric Company 121 S. W. Salmon Street Portland, Oregon 97204 Attention: Mr. Charles Goodwin Assistant Vice President Gentlemen:
Enclosed is IE Bulletin tio. 79-28 which requires action by you with regard to your power reactor facility (ies) with an operating license or a construction permit.
Should you have questions regarding this Bulletin or the actions required of you, please contact this office.
Sincerely, k U~,4C R. H. Engelken Director
Enclosures:
1.
IE Bulletin ilo. 79-28 2.
List of Recently Issued IE Bulletins cc w/ enclosures:
C. P. Yur.dt, PGE F. C. Gaidos, PGE 1774360-7912200 A Y O
i.
UNITED STATES SSINS Mo.: 6820 f1UCLEAR REGULATORY COMMISSION Accession No.:
OFFICE OF INSPECTION Atl0 ENFORCEMEflT 7910250505 WASHIilGTON, D.C.
20555 December 7, 1979 IE Bulletin No. 79-28 POSSIBLE t'ALFUNCTION OF ?!At1C0 frDEL EA180 LIMIT SWITCHES AT TLEVATED TEt'PERATURES Description of Circunstances:
The NRC has been recently advised throuah a 10 CFR 21 report from MAMC0 Controls that a nalfunction of a NA"C0 Model EA180 stem mounted limit switch (SMLS) occurred at the Cooper fluclear Station.
Investigation into the switch failure by the licensee revealed yellow and brown " crystal-like" resin deposits on the internal components of the switch. The affected switch is located inside the drywell containment at this facility and was being used as the replacement switch for an unqualified SPLS previously identified in IE Bulletin flos.
78-0a and 79-01.
According to the manufacturer, the problem was traced to a batch of top cover gaskets of which some were over-inpregnated and insufficiently heat cured.
It has been detennined that this condition can leave an uncured residue of " Loctite" in the gasket, which vaporizes at sustained tenneratures above 1750F. To correct the problen, the nanufacturer has revised oroduction techniques beginning September 1979 in order to better control the iroregnation process and to procerly heat cure the gaskets following incregnation.
This orablem is unique to all flA"C0 Model EA180 series switches received by licensees after March 1,1979.
According to the manufacturer, the suspect switches can be identified by checkina the date code which is a 4 digit number stamped on the conduit boss of the switch housing.
NAMCO recomnends that any EA180 series switch with a date code between 02-79 through 08-79 should have its top cover qasket replaced. Also, licensees should request from their suppliers of equipment on which ?!AMC0 EA180 series switches are used that they check their inventory and replace top cover caskets on switches date coded between 02-79 throuah 08-79.
The enclosed letter from NAPC0 further describes the high-tencerature environ-mental problem with the too cover qaskets used in their EA180 switches and provides recommendations to correct the problem. Accordinq to NAMC0, this letter has been sent to each custoner who was shipped EA180 switches between February 21, 1979, and August 24, 1979.
Action to be Taken by Licensees of Power Peactor Operatino Facilities and Holders of Construction Pemits:
1.
Determine if your facility has switches in any safety-related cuPLICATE DOCUMENT containment, including valve 00 containment isolation valves.
Entire document previously entered into system under:
ANO No. of pages:
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