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| Entered date | Event description | |
|---|---|---|
| ENS 50583 | 30 October 2014 17:15:00 | Staff at the New Milford Cancer Center in New Milford, CT were performing their daily quality assurance checks on their Varian Medical Systems high dose rate (HDR) afterloader when the 7.2 Ci (estimated) Ir-192 source became stuck in the safe position. New Milford contacted the vendor who dispatched a support team to investigate. The Varian RSO surveyed the area and found the dose rate at 5 cm was 1.5 mR/hr which was within normal parameters with the source in the shielded position. While attempting to free the source, it became stuck outside of the shielded position. Dose rates increased to 20 mR/hr at the entrance to the maze, 280 mR/hr at the turn (approximately 15 feet from the HDR) and 5.4 R/hr at 0.5 meters. The service manager was able to use the emergency hand crank to return the source to its shielded position. During the retrieval, the RSO received 9 mR while the service manager received 27 mR. Based on past issues and current symptoms, Varian technicians replaced the drive mechanism and will be installing a new source wire. Once all repairs are made, the HDR will be placed into service with the Varian team on hand during the first post-maintenance use. Varian, an NRC licensee, is making this report since New Milford Cancer Center (license number 0617892-01) did not exceed any reporting thresholds due to this event. The vendor has notified R1 (Modes). See similar events in Event Notifications 46695 and 46758. |
| ENS 46695 | 24 March 2011 16:20:00 | The Varian equipment representative provided notification of the following event that occurred at the Grady Memorial Hospital in Atlanta, GA. A technician was installing a Varisource IX high-dose afterloader when the active wire composed of a 10 Ci Ir-192 source failed to extend. After troubleshooting it was discovered that the wire was stuck on the wedge block which is part of the emergency retract mechanism. The active wire was removed and the emergency retract mechanism was replaced. The technician received 0.2 mrem during the repair work. |
| ENS 43647 | 17 September 2007 17:19:00 | The following information was received via fax: Manufacturer submitted this notification based on an event involving a High Dose Rate (HDR) Afterloader that occurred at City of Hope Hospital in Duarte, California on July 15, 2007 (See EN# 43493) Identification of the facility, the activity, or the basic component supplied for such facility or such activity within the United States which fails to comply or contains a defect- VariSource HDR Afterloader model 200 and VariSource HDR Afterloader model ID Identification of the firm constructing the facility or supplying the basic component which fails to comply or contains a defect: The VariSource HDR Afterloader is manufactured by: Varian-TEM Ltd., Gatwick Road, Crawley, West Sussex RH102RG, United Kingdom Nature of the defector failure to comply and the safety hazard which is created or could be created by such defect or failure to comply: The active source can become dislodged from the internal tungsten safe if the emergency source retract hand crank is used when the active source is safely parked in the internal shield. (1) This event can only occur if the operator turns the emergency hand crank while the source is safely parked. (2) The emergency source retract hand crank is to be used only when the active source is in the out or exposed position. It is not designed, nor intended to be operated when the source is safely parked. (3) The emergency hand crank is only connected to the active source wire. It is not connected to the dummy source and its operation has no effect on the dummy source. Customer Technical Bulletin, CTB-VS-366A, "Clarification on the use of the emergency retract hand wheel to prevent accidental exposure" was issued to all users of the VariSource HDR unit on April 27, 2004. This CTB will be reissued to all domestic customers. A warning label addressing the proper use of the emergency hand crank was attached to all VariSource HDR units in 2004. A new warning label is being developed that will restate the proper use of the hand crank. Also a formal revision was made to user training to emphasize that this event is possible if the user makes an error by operating the emergency hand crank when the active source wire is safely parked in the tungsten shield. There are 186 VariSource HDR units in the United States and a list was provided to the NRC. |