Disposal of Transuranic Solid Waste Using Atomics International's Molten Salt Combustion Process. Ii.

摘要

The Atomics International Molten Salt Combustion Process reduces the weight and volume of combustible transuranic waste by utilizing a molten salt medium to combust organic materials,to trap particulates and fissile material,and to react chemically with any acidic gases produced during combustion. The ''ash''is retained by the molten salt. To control the amount of noncombustible substances in the melt, a portion of the molten salt is periodically drained from the combustor. There are two options following the combustion step:the salt-ash mixture can be cast into a metal canister for direct storage,which is preferred,or the salt-ash mixture can be processed to separate ash for disposal,to recover the salt for recycle and to recover fissile materials. Either option results in the rapid,complete,and nonpolluting destruction of the combustible waste. Bench-scale (0.2kg/hr) combustion tests with plutonium-contaminated waste showed that >99.9percent of the plutonium is retained in the melt during combustion. A similar test with uranium indicated that uranium and plutonium behave identically during combustion. Bench-scale plutonium recovery tests have shown that approx. 98percent of the plutonium can be recovered from the ash-melt mixture with a single acid leach. Pilot plant combustion tests were conducted with uncontaminated shredded waste consisting of paper, Kimwipes,cardboard,rubber,polyvinyl chloride,and polyethylene at feed rates up to 70kg/hr. Hydrogen chloride (<5ppm),sulfur oxide (<1ppm),carbon monoxide (<0.1percent),and hydrocarbon (<0.1percent) emissions were below the detection limits of the instrumentation. The particulate loading varied from 0.1 g/m exp 3at approx. 790exp 0 C to 0.6 g/m exp 3at 1020exp 0 C before the venturi scrubber,and 0.01to 0.04 g/m exp 3 ,respectively,after the scrubber. Downstream of the HEPA filters,no particulates could be detected (<10exp -6 g/m exp 3 ). (ERA citation 01:012607)