ML18081A776
| ML18081A776 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 12/07/1979 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Schneider F Public Service Enterprise Group |
| References | |
| NUDOCS 7912190764 | |
| Download: ML18081A776 (5) | |
Text
UNITED STATES.
NUCLEAR REGULATORY COMMISSION REGION I 631 PARK AVENUE KING OF PRUSSIA, PENNSYLVANIA 19406 Public Service Electric and Gas Company ATTN:
Mr. F. W. Schneider Vice President - Production 80 Park Place Newark, New Jersey 07101 Gentlemen:
The enclosed IE Bulletin No. 79-28, is forwarded for action. A written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely,
Enclosures:
- 1.
- 2.
List of Recently Issued IE Bulletins CONTACT:
S. D. Ebneter (215-337-5296) cc w/encls:
F. P. Librizzi, General Manager - Electric Production E. N. Schwalje, Manager - Quality Assurance R. L. Mittl, General Manager - Licensing and Environment H. J. Midura, Manager - Salem Generating Station
ENCLOSURE 1 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 SSINS No.: 6820 Accession No.. :
7910250505 IE Bulletin No. 79-28 Date: December 7, 1979 Page 1 of 2 POSSIBLE MALFUNCTION OF NAMCO MODEL EA180 LIMIT SWITCHES AT ELEVATED TEMPERATURES Description of Circumstances:
The NRC has been r~cently 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 1 i censee rev ea 1 ed ye 11 ow and brown "crysta 1-1 i ke 11 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 some were over-impregnated and insufficiently heat cured.
It has been determined that this condition can leave an uncured residue of 11 Loctite 11 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. NAMCO 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 NAMCO 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 Operating Facilities and Holders of Construction Permits:
IE Bulletin No. 79-28 Date: December 7, 1979 Page 2 of 2
- 1.
Determine if your facility has installed or plans to install NAMCO EA180 switches in any safety-related equipment located inside or outside contain-ment, including valve position indicating circuitry related to containment isolation valves.
- 2.
If such switches are identified, examine the four digit number stamped on the conduit boss of the switch housing.
If this number falls between 02-79 and 08-79, replace the top gasket of the switch in accordance with the manufacturer 1s recommendations provided in the enclosed letter.
- 3.
Submit your plans and programs, including schedules for corrective action, regarding your findings in response to Items 1 and 2 above.
- 4.
Provide the response in writing within 30 days for facilities holding an operating license and within 60 days for those holders of construction permits.
Reports should be submitted to the Director of the appropriate NRC Regional Office and a copy should be forwarded to the U. S. Nuclear Regulatory Commission, Office of Inspection and Enforcement, Division of Reactor Operations Inspection, Washington, D.C.
20555.
Approved by GAO, 8180225 (R0072); clearance expires July 31, 1980.
Approval was given under a blanket clearance specifically for identified generic problems.
Attachment:
Extract of NAMCO Controls Letter dated 8/30/79
Attention:
Subject:
Gentlemen:
Attachment to IE Bulletin No. 79-28 EXTRACT N A M C 0 C 0 N T R 0 L S August 30, 1979 Possible malfunction of Namco Model EA180 limit switches at elevated ambient temperatures Namco Controls has determined that th~ EA180 series limit switches shipped against you purchase order(s) #
may have top cover gaskets which wili emit a resin vapor at temperatures above 175°F.
This vapor could condense into deposits on the normally open contacts, possibly causing a switch malfunction.
We have reported this situation to the NRC, and we are contacting each customer who has received switches with gaskets from the questionable production lot, with the following recommendations:
a)
If the switches have not been put into service, and the ultimate ambient temperatures are unknown, the top cover gasket should be replaced.
b)
If the switches are in service and are subjected to a continuous ambient temperature of more than 175°F, they should be inspected for deposits, the contacts cleaned if necessary, and have the top cover gasket replaced.
c)
If the switches are in service, (or scheduled for service) in a continuous ambient temperature of 175°F or less, no action is necessary.
We will provide you with whatever number of new top cover gaskets you may require, free of charge.
Or, if you prefer, we will accept switches returned to our Jefferson plant freight collect, for gasket replacement and/or cleaning.
We sincerely regret any inconvenience this remedy may cause.
If you have any questions, please contact either Robert H. Kantner, 216-268-4200 or John R.
Bendokaitis, 216-576-4070.
Bulletin No.
79-23 79-24 79-13 (Rev. 2) 79-17 (Rev. 1) 79-25 79-02 (Rev. 2) 79-26 79-27 ENCLOSURE 2 RECENTLY ISSUED IE BULLETINS Subject Potential Failure of Emergency Diesel Gen-erator Field Exciter Transformer Frozen Lines Date Issued 9/12/79 9/27/79 Cracking in Feedwater *
- 10/17/79 System Piping Pipe Cracks in* Stagnant 10/29/79 Borated Water Systems at PWR Plants Failures of Westinghouse 11/2/79 BFD Relays in Safety-Related Systems Pipe Base Plate Designs 11/8/79 Using Concrete Expansion Bolts Boron Loss From BWR 11/20/79 Control Blades Loss of Non-Class-1-E 11/30/79 Instrumentation and Con-trol Power System Bus During Operation IE Bulletin No. 79-28 Date: December 7, 1979 Page 1 of 1 Issued To All Power Reactor Facilities with an OL or CP All Power Reactor Facilities which have either OLs or CPs and are in late stage of.con-struction All PWRs with an OL
. and Designated Ap-plicants (for Action),
All Other Power Reactor Facilities with an OL or CP (for Information)
All PWRs with an OL (for Action).
All other Power Reactor Facilities with an OL or CP (for Information)
All Power Reactor Facilities with an OL or CP (for Action)
All Power Reactor Facilities with an OL or CP All BWR Power Reactor Facilities with an OL All Power Reactor Facilities with an OL and those nearing Licensing (for Action)
All Power Reactor Facilities with a CP (for Information).