ENS 46758

v t e ENS Event
04:00 Mar 23, 2011
Title	Potential Defect Identified in a Varian Medical Systems High Dose Rate Afterloader
Event Description	On March 23, 2011, a technician was installing a VariSource High Dose Rate (HDR) Afterloader - Model VariSource IX 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. (See NRC Event Notice 46695) Engineering evaluation by the vendor, Varian Medical Systems, Inc., has identified a very small amount of material in the wedge block which has a small bore that the source wire passes through. Otherwise, nothing remarkable was identified. This machine is a new unit with a very low number of source extensions. There is no history of similar events with new units of this type. The vendor has issued a Tech Tip for all new sites and is investigating a new design for the wedge block with a goal of implementing any new design by April 30, 2012. Additionally, all VariSource HDR customers have received a copy of Customer Technical Bulletin CTB-VS-640A that discusses the potential of source wire path constriction and source wire jamming.

ENS 46758 +/-
Where
Varian Medical Systems Charlottesville, Virginia (NRC Region 1)
Organization:	Varian Medical Systems
Reporting

10 CFR 21.21
Time - Person (Reporting Time:+563.2 h23.467 days <br />3.352 weeks <br />0.771 months <br />)
Opened:	Richard G. Piccolo 15:12 Apr 15, 2011
NRC Officer:	Howie Crouch
Last Updated:	Apr 15, 2011
46758 - NRC Website
v • d • e

v t e Emergency Notification System
Varian Medical Systems with 10 CFR 21.21, Notification of failure to comply or existence of a defect and its evaluation
WEEKMONTHYEAR2011-03-23T04:00:00 [Table view]
[ENS list for Varian Medical Systems]

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