The licensee disposed of an ADAC camera in April 2008 and inadvertently failed to remove the 2
Gd-153 sources, isotope products serial numbers E2-886 and E2-890, which contained 250 mCi (9.25 GBq) each as of May 2007. The Gd sources were contained within
lead shielding in the device. The sources in their shielding do not present a hazard. Currently, each of the unshielded sources would present a hazard with an exposure rate of about 124 mr/hr at one foot. Currently, the sources have decayed to around 67 mCi (134 mCi total). As of 7/31/2008, the licensee has not been successful in locating the sources.
According to the licensee, Norcal, a company that performs installation and removal of medical devices, removed the ADAC Vantage camera, and disposed of it sometime in April 2008 to a Waste Transfer Station, Waste Management, in San Leandro.
Waste Management was contacted and provided the names of the 2 metal recycling companies they would have used to recycle the metal. DC Metals and ALCO metals were both contacted and stated that they do not have any such device at their facility. They indicated if they had received it, the gamma camera would have been recycled to scrap metal very quickly.
The RSO stated that she just learned of this incident after their consultant had asked them last week for information regarding the disposition of the two 250 mCi Gd- 153 sources. After checking, they learned the sources had not been removed and were missing. The licensee is investigating to try and determine the location of the missing two Gd-153 sources.
Per report, the discovery date of this event was 7/24/2008.
California Report #073008.
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.
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