RADIOACTIVE PARTICULATE RELEASE FROM THE DOT SPECIFICATION 6M CONTAINER UNDER HYPOTHETICAL ACCIDENT CONDITIONS

A testing programme was conducted to determme the amount of depleted uranium dioxide powder (DUO) that would leak from the inner containment components of the United States Department of Transportation's (DOT) specification 6M container under hypothetical accident conditions. Depleted uranium dioxide was selected as a surrogate for plutonium oxide because of the similarities in powder characteristics, density and particle size and because of the special handling and special facilities required for plutonium oxide. The DUO was packaged inside foodpack cans and then placed inside the 2R vessel of the 6M container. The gas rates of the food-pack cans tested ranged from 1.6 cm3 /s to approximately 38 cm3 /s. The packaging configurations were subjected to 9 m drops, I m drops onto a 15 em diameter cylinder and to heating (inner vessel only) at 150°C in a furnace that could be rotated and vibrated. The DUO leakage rate from the containment barriers after the impact and heating tests was measured using a dissolution technique and a laser fluorometer. The amount of DUO powder leakage ranged from nothing detectable to a high of I X 10-\" g. Impact forces had no effect on the leakage of particles with the packaging configurations used. The tests showed that when the gas leak rate was between 1.6 cm3 /s and 3.2 cm3 /s, the amount of particulate material that could be transmitted through the leak sites would be less than the allowable release limits (?