PHYSICAL CHARACTERISTICS OF HANFORD TANK WASTE RELATING TO FLAMMABLE GAS RETENTION AND RELEASE

All Hanford high-level waste tanks generate flammable gas. Some tanks can accumulate gas and have the potential for a large, sudden release. A good understanding of how gas is retained in the waste and the important mechanisms for its release is required to manage the existing hazard and to prevent new hazards from being created in the future. Almost ten years of tank monitoring, analyses and experiments have shown that the physical characteristics of the waste are the dominant factor in determining tank behavior. This paper will show how the physical configuration and properties of the waste in Hanford tanks affect flammable gas retention and release.