In the solidification of high level radioactive (Purex) wastes by the phosphate glass process de¬veloped at BNL, melter off-gas condensates are produced which consist mainly of nitric acid, sul¬furic acid (with the use of ferrous sulfamate in the solvent extractions), phosphoric acid, and volatil¬ized and entrained fission products, notably ruthe¬nium. Separation and decontamination of the nitric acid and sulfuric acid components by means of vacuum distillation was investigated. The high-est degree of decontamination was obtained at the lowest pressure and temperature. In laboratory-scale, single-distillation experiments maximum de¬contamination factors of 4.3× 103 and 2.2 × 104 were achieved for the nitric acid and the sulfuric acid fractions at 3 mm Hg pressure. Satisfactory separation of both acid fractions was accomplished in laboratory-scale and bench-scale operation.
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