Flotation separation of radionuclides from contaminated Nevada test site (NTS) soil

It is estimated that the volume of low-level and intermediate-level contaminants present in the soil at different DOE sites is of the order of several million cubic feet. The existing remediation scheme is containerization followed by burial in Land Disposal Facilities (LDF's) which is economically unattractive. As a result there is a need to find an economically feasible remediation process. One of the possible approaches is the physical separation based volume reduction. On this process, the radionuclides are concentrated in a small volume and the majority portion of the soil which is clean can be used for the revegetation at the site. The small volume of the contaminated fraction can be containerized or can be further treated.;This research project was devoted towards the development of a decontamination process for dispersed Pu contaminated NTS soil on the basis of physico-chemical characterization and the flotation separation methods. It was observed that a mixture of industrial fatty acid and sodium oleate is an effective collector for the flotation of dispersed plutonium from the fine size soil. The bench-scale mechanical flotation results successfully demonstrated that froth flotation technology can be used to reduce the volume of the contaminated soil. It was possible to separate about 75% of the activity from the gravity underflow of TRUclean process into a concentrate of 14.5% of original feed volume, and the tailing activity was reduced to 141 pCi/gm from an initial feed activity of 552 pCi/gm.