United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 82-48: Failures of AGASTAT CR 0095 Relay Sockets

                                                  SSINS No.: 6835  
                                                  IN 82-48 

                               UNITED STATES 
                       NUCLEAR REGULATORY COMMISSION 
                    OFFICE OF INSPECTION AND ENFORCEMENT 
                          WASHINGTON, D. C. 20555 

                              December 3, 1982 

Information Notice No. 82-48: FAILURES OF AGASTAT CR 0095 RELAY SOCKETS 

Addressees: 

All holders of a nuclear power reactor operating license (OL) or 
construction permit (CP). 

Purpose: 

This information notice is provided as an early notification of a 
potentially significant problem pertaining to Agastat CR 0095 Relay Sockets 
manufactured by Amerace Corporation Control Products Division in Union, New 
Jersey. Because of the potential safety significance and related generic 
implications of this problem, addressees are expected to review the 
information for applicability to their facilities. No specific action or 
response is required at this time. 

Description of Circumstances: 

Since 1978 several deficiencies on Agastat CR 0095 relay sockets have been 
identified: 

1.   On December 21, 1978, Northern States Power Company submitted a 
     Licensee Event Report (LER) for the Monticello nuclear facility. While 
     performing a surveillance test during normal operation, a high pressure 
     instrument channel relay failed to energize. A CR 0095 Agastat relay 
     socket contact was disengaged from the socket and not making contact 
     with the mating Agastat relay contact. 

2.   On January 5, 1979, Alabama Power Company submitted an LER for Farley 
     1 nuclear plant. During a diesel generator operability test, while at 
     100% power level, a sequencer failed to pick up Step 6 (battery 
     charger). After the Agastat relay socket was replaced, the test was 
     satisfactorily completed. 

3.   On April 6, 1979, Northern States Power Company submitted an LER for 
     the Monticello nuclear facility. During a surveillance test a motor 
     generator field breaker trip relay failed to trip the breaker. A CR 
     0095 Agastat relay socket contact was disengaged from the socket and 
     not making contact with the mating Agastat relay contact. 

4.   On December 7, 1979, Detroit Edison submitted a 10 CFR 50.55(e) report 
     No. EF 2-50-658 for the Enrico Fermi 2 nuclear facility. In their two 
     primary containment monitoring system cabinets, problems were 
     experienced with 

8208190261  
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                                                           IN 82-48  
                                                           December 3, 1982 
                                                           Page 2 of 3 

     Agastat relay assemblies. When the relays are plugged into the socket, 
     the terminals are pushed back and this sometimes results in no contact 
     between the relay pin and the socket terminal. 

5.   On June 11, 1981, Florida Power Corporation submitted an LER for 
     Crystal River 3 nuclear facility. During a monthly functional test of 
     engineered safeguards, the load sequence block 3 trip circuit would not 
     reset following the actuation test. The cause was identified as a loose 
     connection in the Agastat relay mounting block. 

Several more LERs since 1978 identified problems of similar nature but did 
not specifically identify the Agastat relay socket as the problem; however, 
the type of failure in specific circuits indicates that the Agastat relay 
socket may be the cause. 

During early 1979 the General Electric Company (GE), Nuclear Energy Business
Operation (NEBO), tested more than 2200 Agastat CR 0095 relay sockets and 
found that a significant number of sockets tested exibited contact retention
problems and potential electrical connection problems. As a result of this 
test and subsequent evaluations; GE, NEBO made recommendations to its 
nuclear customers. 

In February 1979 the Amerace Corporation, Control Products Division 
redesigned and modified the relay base molding by: 

1.   Providing a better guide for the relay male contact into the base 
     (socket) female contact. 

2.   Providing a female contact support behind the female contacts to 
     prevent a push-back. 

3.   Redesigning and modifying the "fast-on" terminal on the relay base. 

These modified Agastat relay sockets were available from the Amerace 
Corporation in the latter part of February 1979 and all Agastat CR 0095 
relay sockets shipped during and after March 1979 were of the redesigned and
modified type. 

Another means of correcting the problem which has been found to be effective
is the installation of cardboard insulator strips behind the relay sockets. 
These strips are available from the Amerace Corporation. 

Agastat CR 0095 relay sockets are used in PWRs as well as in BWRs. While 
most of the nuclear plant owners of BWRs have been made aware of this 
problem by GE-NEBO not all PWR owners are aware or were informed of this 
problem and its resolution. 
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                                                           IN 82-48  
                                                           December 3, 1982 
                                                           Page 3 of 3 

If you have any questions regarding this matter please contact the 
administrator of the appropriate NRC Regional Office. 



                              Edward L. Jordan, Director  
                              Division of Engineering and  
                                Quality Assurance  
                              Office of Inspection and Enforcement 

Technical Contact:  W. Laudan 
                    301-492-9759 

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