United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 89-60: Maintenance of Teletherapy Units

                                  UNITED STATES
                          NUCLEAR REGULATORY COMMISSION
                OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS
                             WASHINGTON, D.C.  20555

                                 August 18, 1989


Information Notice No. 89-60:  MAINTENANCE OF TELETHERAPY UNITS 

Addressees: 

All U.S. Nuclear Regulatory Commission (NRC) Medical Teletherapy Licensees. 

Purpose: 

An information notice provides information to licensees to consider for 
application to their activities.  While an Information Notice provides 
information to improve safety, to improve compliance, or to notify licensees 
of problems or violations of other licensees, it does not establish a new 
requirement or require a written response to the NRC.  

This notice is intended to alert recipients to NRC concerns about proper 
maintenance of teletherapy units.  It emphasizes the importance of five-year 
inspections and services as required by 10 CFR Section 35.647.  It is expected 
that licensees will review this information for applicability to their 
programs, distribute this Notice to those responsible for radiation safety, 
and consider actions, if appropriate, to preclude safety problems from 
occurring at their facilities.  

Description of Circumstances: 

During a routine inspection, NRC inspectors found that the licensee's 
teletherapy unit was in poor condition and significantly overdue for service 
and preventive maintenance, thus raising the question of whether the unit was 
safe to operate.  A service company had performed a five-year inspection in 
August 1988, and found that many parts that the manufacturer considered 
critical components had not been replaced according to the recommended 
frequency.  In fact, many of the critical components were original parts, 
dating from when the unit was first placed into service in 1974. 

Examples of critical components needing periodic replacement are:  the field 
light cord reel, source drawer solenoids, air pressure switch, air hoses and 
fittings, and treatment timer.  If any of these components failed, it could 
significantly increase the potential of the source failing to return to the 
shielded position.  This could lead to unnecessary radiation exposures to both 
employees and patients, or an overexposure or medical misadministration.  In 
fact, the field light cord reel on this unit had failed in 1983, and the 
source could not be fully retracted. 





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.                                                            IN 89-60 
                                                            August 18, 1989 
                                                            Page 2 of 2 


Although the service company informed the licensee of the critical need for 
service, the licensee had not taken any action to service the unit.  
Apparently, the licensee planned to eventually replace the entire unit. 

As a result of the safety concerns raised by NRC, the licensee was required to 
complete the needed service on an emergency basis.  A heavy patient load was 
disrupted temporarily, but the disruption could have been worse if the service 
had taken a long time. 

Discussion: 

Title 10 CFR Section 35.647 requires licensees to have their teletherapy units 
fully inspected and serviced during teletherapy source replacements, or at 
intervals not to exceed five years, whichever comes first.  The purpose of the 
inspection is to assure safe operation of the units, specifically proper 
functioning of the source exposure mechanism.  

Licensees should pay close attention to the results of their five-year 
inspections, and assure that recommended service is performed promptly.  
Failure to maintain teletherapy units in safe operating condition could result 
in radiation incidents and/or enforcement action by NRC. 

This information notice does not require any written response.  If you have 
any questions about this matter, please contact the appropriate NRC Regional 
Office or this office. 




                                        Richard E. Cunningham, Director
                                        Division of Industrial and 
                                          Medical Nuclear Safety, NMSS

Technical Contacts:  Jack R. Metzger, NMSS
                     (301) 492-3424

                     R. J. Caniano, Region III
                     (312) 790-5721

Attachments:
1.  List of Recently Issued NMSS Information Notices
2.  List of Recently Issued NRC Information Notices 
.                                                            Attachment 2 
                                                            IN 89-60 
                                                            August 18, 1989 
                                                            Page 1 of 1

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

89-59          Suppliers of Potentially      8/16/89        All holders of OLs
               Misrepresented Fasteners                     or CPs for nuclear
                                                            power reactors. 

89-58          Disablement of Turbine-Driven 8/3/89         All holders of OLs
               Auxiliary Feedwater Pump Due                 or CPs for PWRs. 
               to Closure of One of the 
               Parallel Steam Supply Valves 

89-57          Unqualified Electrical        7/26/89        All holders of OLs
               Splices in Vendor-Supplied                   or CPs for nuclear
               Environmentally Qualified                    power reactors. 
               Equipment 

89-56          Questionable Certification    7/20/89        All holders of OLs
               of Material Supplied to the                  or CPs for nuclear
               Defense Department by Nuclear                power reactors. 
               Suppliers 

89-45,         Metalclad, Low-Voltage        7/6/89         All holders of OLs
Supp. 1        Power Circuit Breakers                       or CPs for nuclear 
               Refurbished With Substandard                 power reactors. 
               Parts 

89-55          Degradation of Containment    6/30/89        All holders of OLs
               Isolation Capability by a                    or CPs for nuclear
               High-Energy Line Break                       power reactors. 

89-54          Potential Overpressurization  6/23/89        All holders of OLs
               of the Component Cooling                     or CPs for nuclear
               Water System                                 power reactors. 

89-53          Rupture of Extraction         6/13/89        All holders of OLs 
               Steam Line on High                           or CPs for nuclear 
               Pressure Turbine                             power reactors. 

88-46,         Licensee Report of            6/8/89         All holders of OLs
Supp. 3        Defective Refurbished                        or CPs for nuclear
               Circuit Breakers                             power reactors. 

89-52          Potential Fire Damper         6/8/89         All holders of OLs
               Operational Problems                         or CPs for nuclear
                                                            power reactors. 
______________________________________________________________________________
OL = Operating License
CP = Construction Permit 
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