Bulletin 92-02: Safety Concerns Relating to "End of Life" of Aging Theratronics Teletherapy Units
OMB No. 3150-0009 NRCB 92-02 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS WASHINGTON, D.C. 20555 August 24, 1992 NRC BULLETIN 92-02: SAFETY CONCERNS RELATING TO "END OF LIFE" OF AGING THERATRONICS TELETHERAPY UNITS Addressees For Action - All Teletherapy Licensees For Information - None Purpose This bulletin: (1) notifies you about concerns related to the useful safe life of older Theratronics International Limited (formerly AECL Medical) teletherapy units; (2) requests that all action addressees take the appropriate recommended actions; and (3) requires that all action addressees provide the U.S. Nuclear Regulatory Commission with a report describing their findings and actions taken and notify NRC when they have completed all actions associated with this bulletin. Description of Circumstances Beginning with the discovery of crack(s) in the cast iron arms of a Theratron 80 (T80) teletherapy unit in 1983, Theratronics has issued three "User Bulletins" to all consignees of Theratron 60's (T60's) and T80's. These bulletins all addressed the necessity of inspecting the arms in accordance with a revised maintenance section of the unit's instruction manual. In 1991, the Center for Devices and Radiological Health of the Food and Drug Administration (FDA) became concerned about this possible safety issue and inspected Theratronics, concentrating primarily on the cobalt therapy devices. In addition to the problem with the cracked arms, the FDA inspection found that the firm had other continuing problems with the T60 and T80 units. These problems include gantry rotation and timer malfunctions, stuck sources, optical distance indicator errors, problems with bolts, pins, and screws, and inadvertent raising of the patient couch without switch activation. As a result of the problems uncovered during FDA inspections, Theratronics voluntarily issued a user bulletin that was classified as a "Safety Alert" by FDA in May 1991 (FDA # M-020/021-1). This bulletin advised all T60 and T80 users of the potential for cracking in the arms of their units. In addition, as the result of the inspections Theratronics subsequently issued a number of user bulletins affecting various firm products that were classified as "Recalls" by FDA. FDA has also placed in effect an "Import Alert" preventing the importation of all of the firm's radiation therapy treatment and planning 9208180147. NRCB 92-02 August 24, 1992 Page 2 of 5 systems from Canada. The latter action will remain in effect until the company satisfies the FDA that the problems uncovered in the FDA's inspection of the firm are corrected. After these actions, Theratronics issued two "User Bulletins" -- CUB-91-03NA, dated June 5, 1991, and CUB-91-04NA, dated June 24, 1991 (Attachments 1 and 2). The purpose of these bulletins was to inform users of the firm's Theratron Junior, Eldorado A, Eldorado G, Eldorado Super G, Ceasatron E, Eldorado 6 and Eldorado 8 (CUB-91-03NA) and users of its Theratron 60 and 80 (CUB-91-04NA) teletherapy units that, in the opinion of the manufacturer, these units have exceeded their useful safe life and should be removed from service, especially those units with cast iron components. The manufacturer also stated that spare parts were becoming increasingly difficult to provide and, in some cases, were completely unavailable. As of the issue date of the respective bulletins, the manufacturer further stated that routine service, service contracts, replacement sources, and accessories would no longer be made available. Further, spare parts would only be supplied on an "as available" basis. Discussion The potential hazard to patients and employees from crushing injuries due to catastrophic failure of the arm is obvious. In 1987, a mechanical failure in the drive unit of an aging Eldorado 6 unit resulted in a crushing fatality to a patient. Such failures could also expose, or leave exposed, the source. In such an event, significant exposures to the patient and/or employees could readily occur, particularly if the failure rendered inoperable the normal emergency source-retraction mechanisms. A worst-case scenario -- an injured individual trapped in the treatment room with an exposed source -- could lead to a fatal overexposure. The broader safety issues related to the withdrawal of the manufacturer's support for these units concern NRC. This lack of support may lead to incidents of deferred or improper maintenance at a time when service and maintenance requirements are normally increasing as components age. Improper servicing, repair, or substitution of spare parts could readily produce device failures resulting in overexposures to both patients and employees. The Theratronics International Limited teletherapy models affected by the manufacturer's withdrawal of support are: Theratron Junior Eldorado A Eldorado G Eldorado Super G Ceasatron E Eldorado 6 Eldorado 8 Theratron 60 Theratron 80 and 80R . NRCB 92-02 August 24, 1992 Page 3 of 5 In addition, the Theratron 60 and 80 models are subject to cracks developing in the cast iron arm. Requested Actions Those addressees possessing one or more of the affected models must submit the information specified under "Reporting Requirements" within 60 days after receipt of this bulletin. Those addressees who do not have one of the listed models need only submit an abbreviated report listing the make(s) and model(s) they possess, along with a statement that, based on make(s) and/or model(s), they are exempt from the additional reporting requirements of this bulletin. Reporting Requirements Provide information on how you are going to handle the "end-of-useful-life" issue and the maintenance and servicing issues related to the manufacturer's withdrawal of support. At a minimum, the following information should be included in your report: (1) Make and model number of teletherapy unit (2) Date of manufacture (if known) (3) Serial number (4) Describe the present use of your teletherapy unit, (e.g., research, instrument calibration, routine clinical use, backup for an accelerator, etc). If used for patient treatment, what is the average weekly patient workload and what alternative(s) are available to treat these patients if the unit had to be removed from service for an extended period of time for service or replacement? (5) If you possess one of the T60 or T80 units with a cast iron arm, describe your commitment to perform the special inspections per Theratronic's revised Survey and Inspection Procedure I 1024 G091G10 REV C. and your action(s) if stress cracking is discovered. (6) What has been the service record of your teletherapy units for the past five years? List each failure, its cause, length of down time, and replacement components, if any, necessary to return the unit to service. (7) Is your teletherapy unit presently covered by a service contract and, if so, by whom? What is the expiration date of the contract? Do you expect to renew the contract and, if so, for what additional period of time? What is covered by the contract? (8) Describe your facility's commitment to ensure the continued safe clinical use of these aging teletherapy units. At a minimum, you should address the following concerns:. NRCB 92-02 August 24, 1992 Page 4 of 5 (a) Inspections (i) Frequency (ii) What will be inspected? (iii) Who will perform the inspections? (iv) Operational checks (b) Service (i) Prearranged or on an "as-required" basis? (ii) If prearranged, specify by agreement or service contract (iii) Who will perform the service? (c) Parts replacement (i) How necessary replacement parts will be obtained (ii) How suitability of any replacement parts (equal or better) will be determined (d) Service, source exchange and 5-year inspections (i) Identify the name of the organization(s) that will perform these services and specify the firm's NRC or Agreement State license number (ii) If you have no organization identified to perform these services, then what are your plans at source-exchange time and/or 5-year inspection. (e) For any needed repairs or essential inspections for which necessary resources are unavailable or delayed, you must commit to halting all use of the unit until the necessary repairs and/or inspection have been accomplished. Address the required written reports to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, D.C. 20555, under oath or affirmation, under the provisions of Section 182a, Atomic Energy Act of 1954, as amended. In addition, submit a copy to the appropriate regional administrator. This request is covered by Office of Management and Budget Clearance Number 3150-0017, which expires February 28, 1993. The estimated average number of burden hours is 20 person-hours per licensee response, including those needed to assess the new recommendations, search data sources, gather and analyze the data, and prepare the required letters. (This estimate of the average number of burden-hours pertains only to the identified response-related matters and does not include the time needed to implement the requested action.) Send comments about this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to the Information and Records Management Branch, Division of Information Support Services, Office of Information Resources Management, U.S. Nuclear Regulatory Commission, Washington, D.C. 20555, and to the Paperwork Reduction Project . NRCB 92-02 August 24, 1992 Page 5 of 5 (3150-0017), Office of Information and Regulatory Affairs, NEOB-3019, Office of Management and Budget, Washington, D.C. 20503. Although no specific request or requirement is intended, the following information would be helpful to NRC in evaluating the cost of complying with this bulletin: (1) The licensee staff's time and costs to perform requested inspections, corrective actions, and associated testing (2) The licensee staff's time and costs to prepare the requested reports and documentation (3) The additional short-term costs incurred as a result of the inspection findings such, as the costs of the corrective actions or the costs of down time (4) An estimate of the additional long-term costs that will be incurred in the future as a result of implementing commitments such as the estimated costs of conducting future inspections or increased maintenance If you have any questions about this matter, please contact the technical contact listed below or the appropriate regional office. ORIGINAL SIGNED BY Richard E. Cunningham, Director Division of Industrial and Medical Nuclear Safety, Office of Nuclear Material Safety and Safeguards Technical contact: Robert L. Ayres, IMAB 301-504-3423 Attachments: 1. CUB-91-03NA 2. CUB-91-04NA 3. List of Recently Issued NMSS Bulletins 4. List of Recently Issued NRC Bulletins .
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