The State provided the following information via email:
On Monday, September 10, 2007, the Minnesota Department of Health (MDH) was notified by American Engineering and Testing that a fire had destroyed a Troxler Model 3430 moisture density gauge. The fire occurred at a private residence, which was a farm, and spread to a pick-up truck that was parked beside the garage to that residence. The fire melted the plastic components of the gauge but did not effect the Cesium-137 source in the source rod or the Americium-241:Beryllium source that was in the lead shielding. Members of the Fire Department who responded to the fire were instructed to maintain a safe distance from the truck to avoid minimize radiation exposures.
MDH completed radiation and contamination surveys of both sources. No contamination was detected and the radiation levels were as would be expected with the shielding intact. The sources were placed in containers filled with sand to provide shielding and removed to a secure permanent storage location. The RSO and the Corporate RSO will complete leak tests and arrange for the appropriate containers for shipment to the manufacturer.
The gauge was a Troxler Model 3430, Serial Number 23279, which contained approximately 9 millicuries of Cesium-137 (Serial Number 75-5294) and 44 millicuries of Americium-241:Be (Serial Number 47-19161).
Minnesota Report number: MN07005
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.