The use of bitumen in the stabilization of mixed wastes

Mixed wastes pose a problem to generators since there are no burial sites or treatment facilities currently accepting this type of waste. One potential disposal method is treating the waste to render it nonhazardous and disposing of it in accordance with radioactive waste requirements. A possible means of accomplishing this transformation is solidifying the waste in asphalt (bitumen). The authors have solidified in asphalt a surrogate sodium nitrate-based waste, spiked with extraction procedure (EP) toxic metals and nonradioactive cesium and strontium. This paper reports the characteristics of the spiked solution that was solidified as well as the properties of the solidified end product. The waste samples generated underwent EP toxicity testing as well as American Nuclear Society (ANS) 16.1 leach testing for 90 days, and the results of these tests are presented. Also, a discussion of the criteria for classifying a waste as hazardous is included in order to demonstrate that the waste, once solidified in asphalt, can no longer be considered hazardous