On November 23, 2011, during a physical inventory of
iodine-125 seeds to be returned to the vendor, it was determined that one (1)
iodine-125 eye plaque seed was missing. The patient and room surveys were conducted at the time of the
eye plaque procedure (late May) to verify no seed had been left in the patient or the room, and that all sources were returned from the procedure to the source storage room. The manufacturer's assay was 2.94 mCi per seed on May 20, 2011. The assay at the time of the procedure was within 3% of the manufacturer's assay. All attempts to identify the time, location, or the passage of disposal did not produce a definite result.
The Wisconsin Department of Health Services (DHS) followed up with the licensee by phone and will conduct an investigation the first week of December.
Event Report No.: WI110020
THIS MATERIAL EVENT CONTAINS A "LESS THAN CAT 3" LEVEL OF RADIOACTIVE MATERIAL
Sources that are "Less than IAEA Category 3 sources," are either sources that are very unlikely to cause permanent injury to individuals or contain a very small amount of radioactive material that would not cause any permanent injury. Some of these sources, such as moisture density gauges or thickness gauges that are Category 4, the amount of unshielded radioactive material, if not safely managed or securely protected, could possibly - although it is unlikely - temporarily injure someone who handled it or were otherwise in contact with it, or who were close to it for a period of many weeks. For additional information go to http://www-pub.iaea.org/MTCD/publications/PDF/Pub1227_web.pdf
This source is not amongst those sources or devices identified by the
IAEA Code of Conduct for the Safety & Security of Radioactive Sources to be of concern from a radiological standpoint. Therefore is it being categorized as a less than Category 3 source