Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Evaporation characteristics of a reprocessing plant HLLW concentrator

Conference · · Transactions of the American Nuclear Society; (USA)
OSTI ID:5533354
In a high-level liquid waste (HLLW) concentrator at an industrial Purex reprocessing plant, the HLLW evaporation behavior would be rather complicated due to the large number of fission product ions present in the waste. Under a reduced-pressure evaporation process, experiments with simulated acidic solution show that the nitric acid concentration of the liquid phase initially increases from that of feed solution, i.e., 3 to {approx} 9 mole/l rather rapidly, but subsequently, instead of keeping this value, it decreases gradually and finally approaches {approx}7 mol/l. In the present work, modeling was carried out in regard to vapor/liquid equilibria of nitric acid containing highly concentrated fission product nitrates, where the related reduction of nitric acid is attributed to the salt effect, which is enhanced as the fission product concentration increases. Using this model, quantitative evaluations were made in regard to the nitric acid concentration during the HLLW evaporation. The results of the simulation were examined by the experiments using a 1/200-scale pilot plant of an actual plant for HLLW concentration.
OSTI ID:
5533354
Report Number(s):
CONF-881011--
Conference Information:
Journal Name: Transactions of the American Nuclear Society; (USA) Journal Volume: 57
Country of Publication:
United States
Language:
English