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.