Patent Number: 046363360
Section: claims

1. A process for reducing the volume of a low-level radioactive liquid waste containing an organic amine chelating agent comprising: burning a fuel and an oxygen-containing gas to produce a hot gas stream having a temperature in excess of the thermal decomposition temperature of the chelating agent;  introducing the hot gas stream into a spray drying zone;  introducing a finely atomized spray of said liquid waste into said spray drying zone and into intimate contact with said hot gas stream;  controlling the proportions of said hot gas stream and said liquid waste to rapidly evaporate water from said liquid waste and cool said hot gas to a temperature below the decomposition temperature of said chelating agent in a time of less than six seconds to produce (a) a dry, flowable powder product including said chelating agent, and (b) a product gas substantially free of any gaseous products of said chelating agent and volatile fission products of the radioactive constituents of said liquid waste; and  separating said powder product from said product gas. 2. The process of claim 1 wherein said chelating agent is an organic amine acid compound. 3. The process of claim 2 wherein said chelating agent is selected from the group consisting of EDTA, DTPA, HEDTA and NTA. 4. The process of claim 3 wherein said hot gas stream has a temperature within the range of 250.degree. to 400.degree. C. 5. The process of claim 4 wherein said hot gas is cooled to a temperature of from about 150.degree. to 200.degree. C. in a time within the range of from about 1 to 6 seconds. 6. The process of claim 5 wherein said time is within the range of from about 1.5 to 3 seconds. 7. The process of claim 6 wherein said chelating agent is EDTA. 8. The process of claim 5 wherein the gas is further cooled to a temperature of less than about 90.degree. C. prior to separating said powder product from said product gas.