Physiochemical and Plutonium Retention Properties of Hydrolytic and Radiolytically Degraded Tri-n-Amylphosphate

摘要

Hydrolytic and radiolytic degradation of tri-n-amylphosphate (TAP) diluted in normal paraffin hydrocarbon (NPH) in the presence of nitric acid has been investigated.Physicochemical properties such as density,viscosity,and phase disengagement time (PDT) were measured for undegraded and degraded solutions.The extent of damage caused by chemical and radiation induced reactions in TAP-NPH-HNO_3 system has been assessed by the measurement of plutonium retention in the organic phase.The results are compared with those obtained using undegraded TAP as well as tri-n-butylphosphate (TBP) in NPH.The effectiveness of sodium carbonate washing of the degraded organic phase for restoring the original quality of the solvent has been detailed.The study indicates that plutonium retention exhibited by TAP/NPH is insignificant at dose levels typically encountered in the first extraction cycle (approx 0.2 kGy),and the marginal increase of plutonium retention at higher dose levels is not,however,undesirable for the employment of TAP in an actual process.