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Information Notice No. 83-45: Environmental Qualification Test of General Electric Company "CR-2940" Position Selector Control Switch
SSINS No.: 6835 IN 83-45 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D. C. 20555 July 1, 1983 Information Notice No. 83-45: ENVIRONMENTAL QUALIFICATION TEST OF GENERAL ELECTRIC COMPANY "CR-2940" POSITION SELECTOR CONTROL SWITCH Addressees: All holders of a nuclear power reactor operating license (OL) or construction permit (CP). Purpose: This information notice is provided as a notification of a potentially significant problem pertaining to the premature degradation and failure of a Dupont TM "Delrin" switch cam within the General Electric (GE) "CR-2940" four-position selector switch. It is expected that recipients will review the information for applicability to their facilities. No specific action or response is required. Description of Circumstances: Recently, the Philadelphia Electric Company performed environmental qualification testing on the General Electric (GE) position control switch, model "CR-2940". On January 5, 1983, the Philadelphia Electric Company reported to the NRC that the test speciman failed to function following the radiation aging phase, after it was exposed to a radiation dose of 37 megarads (33.5 megarads plus margin). Upon disassembly of the test speciman, the cause for failure was attributed to the Dupont TM "Delrin" material used specifically for the switch cam. The cam material was found to have fractured into many small pieces, thereby changing the setting of the contact arrangement of the four-way position switch during the test. The Philadelphia Electric Company indicated that the model "CR-2940" control switch was installed at the Peach Bottom facilities to operate safety-related equipment in the RHR, Core Spray, HPCI, and the RCIC pump rooms. The licensee reported that as an immediate corrective measure, necessary wiring modifications to the GE "CR-2940" control switches were made to assure that safety-related equipment will function as required at the Peach Bottom facilities. Furthermore, the licensee is reviewing long term actions to provide switches which will meet environmental requirements. Another related matter involved a recent 10 CFR 50.55(e) report to the NRC from the Cleveland Electric Company on the GE "CR-2940" tandem block switch assemblies. The report highlights that these switch assemblies contained blocks with loose mounting screws, and these screws were retightened and retorqued. 8305110503 . IN 83-45 July 1, 1983 Page 2 of 2 If you have questions regarding this matter, please contact the Regional Administrator of the appropriate NRC Regional office, or this office. Edward L. Jordan Director Division of Emergency Preparedness and Engineering Response Office of Inspection and Enforcement Technical Contact: N. B. Le, IE (301) 492-9673 Attachment: List of Recently Issued IE Information Notices .
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