United States Nuclear Regulatory Commission - Protecting People and the Environment

Potential Electrical Equipment Problems

                                  UNITED STATES
                          NUCLEAR REGULATORY COMMISSION
                            WASHINGTON, D. C.  20555

                                January 11, 1989



All Fuel Cycle and Major Nuclear Materials licensees.


This information notice is being provided to advise certain NRC fuel cycle and
materials licensees of potential electrical equipment problems that may be 
caused by inadequate maintenance, equipment component defects, or procurement 
practices.  It is expected that you will review this information for appli-
cability, distribute it to responsible radiation safety, maintenance and 
procurement staff, and consider actions, as appropriate, to avoid similar 
problems.  However, suggestions contained in this notice do not constitute 
new NRC requirements; no written response is required.

Description of Circumstances:

Concerns regarding electrical equipment problems with materials licensees 
were prompted by recent inspection findings that counterfeit, substandard, 
or questionable electrical equipment or components had been used in nuclear 
power reactors.  The inspection findings indicated that the electrical equip-
ment problems appeared to be significant and pervasive.  As a result, several 
NRC information notices were issued which reflected such equipment problems
involving nuclear utilities, equipment manufacturers, and vendors.  Further-
more, several electrical suppliers were identified as those associated in 
refurbishing and sale of defective equipment components to nuclear and non-
nuclear industries.  Therefore, the electrical equipment problem does not 
appear to be confined to nuclear power reactors or the nuclear industry.  
Similar problems may also exist in non-nuclear medical and industrial 
operations as well.

A review of previously published NRC information notices and bulletins ad-
dressed to materials licensees revealed that there had been incidents which 
involved failure of electrical equipment and components such as pressure 
regulator switches, teletherapy timers, solid-state relays, and solenoid 
valves, which could have resulted in radiation overexposures.  A brief 
description of the incidents is provided below:

.                                                            IN 89-03
                                                            January 11, 1989
                                                            Page 2 of 3

1.   Information Notice No. 84-77:

     A defective solid-state relay in a circuit board of a teletherapy unit 
     caused the source unit to move to the exposed position.  This could 
     cause both the teletherapy operator and the patient to receive excessive 
     radiation exposures.  This incident also may have generic implications 
     because of the non-fail-safe design of the relay circuit.

2.   Information Notice No. 85-54:

     A failure of a pressure regulator switch on the pneumatic system to an 
     Atomic Energy of Canada, Ltd. (AECL) Theratron 60 teletherapy unit caused 
     an overpressure condition in the holding tank and prevented the source 
     drawer from immediately closing on command.
3.   IE Bulletin No. 86-04:

     The bulletin described how an operational malfunction of a teletherapy 
     timer could result in radiation misadministration to patients and possible 
     excessive radiation exposures to teletherapy operators.

4.   Information Notice No. 87-29:

     The Notice described several-related incidents at large irradiators.
     One event involved an irradiator source unable to retract to its fully 
     shielded position due to a frozen solenoid valve.

Although these incidents apparently did not involve counterfeit equipment, 
these incidents illustrate the need for facility management to have an 
adequate maintenance and procurement program.  Therefore, licensees are 
urged to thoroughly review their programs to ensure that the procedures 
for operations, service, repair, or replacement are being followed properly.  
Licensees should also review their procurement procedures and practices, 
especially in areas such as purchase orders, materials requirements, vendor 
qualifications, and receipt inspections, to ensure quality control and 
.                                                            IN 89-03 
                                                            January 11, 1989
                                                            Page 3 of 3

No specific action or written response is required by this information notice.  
If you should have any questions about this matter, please contact the 
the appropriate NRC regional office or the technical contact listed below.

                                   Richard E. Cunningham, Director
                                   Division of Industrial and
                                     Medical Nuclear Safety
                                   Office of Nuclear Material Safety
                                     and Safeguards

Technical Contact:  K. C. Leu, NMSS
                    (301) 492-0696

1. List of Recently Issued NMSS Information Notices
2. List of All Recently Issued NRC Information Notices

.                                                            Attachment 2
                                                            IN 89-03
                                                            January 11, 1989
                                                            Page 1 of 1

                             LIST OF RECENTLY ISSUED
                             NRC INFORMATION NOTICES
Information                                  Date of 
Notice No._____Subject_______________________Issuance_______Issued to________

89-02          Criminal Prosecution of       1/9/89         All holders of a
               Licensee's Former President                  U.S. NRC specific
               for Intentional Safety                       license.

88-23,         Potential for Gas Binding     1/5/89         All holders of OLs
Supp. 1        of High-Pressure Safety                      or CPs for PWRs.
               Injection Pumps During a
               Loss-of-Coolant Accident

89-01          Valve Body Erosion            1/4/89         All holders of OLs
                                                            or CPs for nuclear
                                                            power reactors.

88-46,         Licensee Report of Defective  12/30/88       All holders of OLs
Supp. 2        Refurbished Circuit Breakers                 or CPs for nuclear
                                                            power reactors.

88-101         Shipment of Contaminated      12/28/88       All holders of OLs
               Equipment between Nuclear                    or CPs for nuclear
               Power Stations                               power reactors.

88-100         Memorandum of Understanding   12/23/88       All major nuclear
               between NRC and OSHA                         materials licensees
               Relating to NRC-licensed                     and utilities 
               Facilities (53 FR 43950,                     holding CPs and 
               October 31, 1988)                            OLs. 

88-99          Detection and Monitoring      12/20/88       All holders of OLs
               of Sudden and/or Rapidly                     or CPs for PWRs.
               Increasing Primary-to-
               Secondary Leakage

88-98          Electrical Relay Degradation  12/19/88       All holders of OLs
               Caused by Oxidation of                       or CPs for nuclear
               Contact Surfaces                             power reactors.

88-97          Potentially Substandard       12/16/88       All holders of OLs
               Valve Replacement Parts                      or CPs for nuclear
                                                            power reactors.
OL = Operating License
CP = Construction Permit 
Page Last Reviewed/Updated Friday, May 22, 2015