The State provided the following information via email:
The licensee purchased the facility in December of 2006 from Hartland Warehouse. Upon receiving the State of Nebraska's annual inventory of Generally Licensed Devices in April of 2007, they did an inventory and found the following sign missing: Isolite Exit Sign model 2040-01-02 containing 10 curies of H-3 in January of 1992 and serial #1135.
The current licensee believes that the missing sign was located on the second floor of the office at one time. A door that led to a landing on the second floor and stair steps that led down to the first floor at sometime previously were torn down and the door blocked off. The licensee believes that the sign was removed and disposed of in the landfill.
Nebraska Event Number: NE070003
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