ML19211C116
| ML19211C116 | |
| Person / Time | |
|---|---|
| Issue date: | 12/18/1979 |
| From: | Carroll D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Wright G ILLINOIS, STATE OF |
| References | |
| NUDOCS 8001100097 | |
| Download: ML19211C116 (2) | |
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UNITED STATES
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GLEN ELLYN. ILLINolS 60137 DEC ] 81979 State of Illinois Department of Public Health ATTN:
Mr. Gary N. Wright, Chief Division of Nuclear Safety 535 West Jefferson Street Springfield, IL 62761 Gentlemen:
The enclosed IE Bulletin No. 79-28 titled "Possible Malfunction of Namco Model EA 180 Limit Switches at Elevated Temperatures" was sent to the following licensees on December 7, 1979, for acti:n:
American Electric Power Service Corporation Indiana and Michigan Power Company D. C. Cook 1, 2 (50-315, 50-316)
Cincinnati Gas & Electric Company Zimmer (50-358)
Cleveland Electric Illuminating Company Perry 1, 2 (59-440, 50-441)
Commonwealth Edison Company Braidwood ], 2 (50-456, 50-457)
Byron 1, 2 (50-454, 50-455)
Dresden 1, 2, 3 (50-10, 50-237, 50-249)
La Salle 1, 2 (50-373, 50-374)
Quad-Cities 1, 2 (50-254, 50-265)
Zion 1, 2 (50-295, 50-304)
Consumers Power Company Big Rock Point (50-155)
Midland 1, 2 (50-329, 50-330)
Palisades (50-255)
Dairyland Power Cooperative 177p 9g LACBWR (50-409)
II >v LU Detroit Edison Company Fermi 2 (50-341)
Illinois Power Company Clinton 1, 2 (50-461, 50-462)
,f 800110 0
Uf.' ] li S/3 State of Illinois Iowa Electric Light & Power Company Duane Arnold (50-331)
Northern Indiana Public Service Company Bailly (50-367)
Northern States Power Company Monticello (50-263)
Prairie Island 1, 2 (50-282, 50-306)
Ohio Edison Company Erie 1, 2 (50-580, 50-581)
Public Service of Indiana Marble Hill 1, 2 (50-546, 50-547)
Toledo Edison Company Davis-Besse 1 (50-346)
Union Electric Company Callaway 1, 2 (50-483, 50-486)
Wisconsin Electric Power Company Point Beach 1, 2 (50-266, 50-301)
Wisconsin Public Service Corporation Kewaunee (50-305)
Sincerely, El h.
I l f M/.
brothyE Carroll, Acting Chief Administrative Branch
Enclosure:
IE Bulletin No. 79-28 cc w/ encl:
Mr. D. W. Kane,
/
"~ f Sarger& & Lundy j/
O 704 Central Files iI U
LUV Reproduction Unit NRC 20b Local PDR NSIC TIC
UNITED STATES SSINS No.: 6820 NUCLEAR REGULATORY COMMISSION Accession No.:
OFFICE OF INSPECTION AND ENFORCEMENT 7910250505 WASHINGTON, D.C.
20555 December 7, 1979 IE Bulletin No. 79-28 POSSIBLE MALFUNCTION OF NAMC0 MODEL EA180 LIMIT SWITCHES AT ELEVATED TEMPERATURES Description of Circumstances:
The NRC has been recently advised through a 10 CFR 21 report from NAMCO Controls that a malfunction of a NAMCO Model EA180 stem mounted limit switch (SMLS) occurred at the Cooper Nuclear 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 SMLS previously identified in IE Bulletin Nos.
78-04 and 79-01.
According to the manufacturer, the problem was traced to a batch of top cover gaskets of which sorce were over-impregnated and insufficiently heat cured.
It has been determined that this condition can leave an uncured residue of " Loctite" in the gasket, which vaporizes at sustained temperatures above 175 F.
To correct the problem, the manufacturer has revised production techniques beginning September 1979 in order to better control the impregnation process and to properly heat cure the gaskets following impregnation.
This problem is unique to all NAMCO Model EA180 series switches received by licensees after March 1, 1979.
According to the manufacturer, the suspect switches can be identified by checking the date code which is a 4 digit number stamped on the conduit boss of the switch housing.
NAMC0 recommends that any EA180 series switch with a date code between 02-79 through 08-79 should have its top cover gasket replaced.
Also, licensees should request from their suppliers of equipment on which NAMCO EA180 series switches are used that they check their inventory and replace top cover gaskets on switches date coded between 02-79 through 08-79.
The enclosed letter from NAMC0 further describes the high-temperature environ-mental problem with the top cover gaskets used in their EA180 switches and provides recommendations to correct the problem.
According to NAMCO, this letter has been sent to each customer who was shipped EA180 switches between February 21, 1979, and August 24, 1979.
Action to be Taken by Licensees of Power Reactor Operatin,q Facilities and Holders of Construction Permits:
1/'38 28/
1.
Determine if your facility has L switches in any safety-related e' DUPLICATE DOCUMENT containment, including valve pos containment isolation valves.
Entire document previously entered into system under:
h ANO No. of pages:
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