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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 . 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. . 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 Attachment: List of Recently Issued IE Information Notices
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