DECONTAMINATION/DESTRUCTION TECHNOLOGY DEMONSTRATION FOR ORGANICS IN TRANSURANIC WASTE

The United States Department of Energy's Savannah River Site has approximately 5000 55-gallon drums of {sup 238}Pu contaminated waste in interim storage. These may not be shipped to WIPP in TRUPACT-II containers due to the high rate of hydrogen production resulting from the radiolysis of the organic content of the drums. In order to circumvent this problem, the {sup 238}Pu needs to be separated from the organics--either by mineralization of the latter or by decontamination by a chemical separation. We have conducted ''cold'' optimization trials and surrogate tests in which a combination of a mediated electrochemical oxidation process (SILVER II{trademark}) and ultrasonic mixing have been used to decontaminate the surrogate waste materials. The surrogate wastes were impregnated with copper oxalate for plutonium dioxide. Our process combines both mineralization of reactive components (such cellulose, rubber, and oil) and surface decontamination of less reactive materials such as polyethylene, polystyrene and polyvinylchloride. By using this combination of SILVER II and ultrasonic mixing, we have achieved 100% current efficiency for the destruction of the reactive components. We have demonstrated that: The degree of decontamination achieved would be adequate to meet both WIPP waste acceptance criteria and TRUPACT II packaging and shipping requirements; The system can maintain near absolute containment of the surrogate radionuclides; Only minimal pre-treatment (coarse shredding) and minimal waste sorting are required; The system requires minimal off gas control processes and monitoring instrumentation; The laboratory trials have developed information that can be used for scale-up purposes; The process does not produce dioxins and furans; Disposal routes for secondary process arisings have already been demonstrated in other programs. Based on the results from Phase 1, the recommendation is to proceed to Phase 2 and use the equipment at Savannah River Site to demonstrate the processing of genuine plutonium contaminated wastes