United States Nuclear Regulatory Commission - Protecting People and the Environment

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
                           WASHINGTON, D. C. 20555
                                July 1, 1983

                                   GENERAL ELECTRIC COMPANY "CR-2940" 
                                   POSITION SELECTOR CONTROL SWITCH 


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


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 


                                                               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

List of Recently Issued IE Information Notices
Page Last Reviewed/Updated Friday, May 22, 2015