用于动力堆核燃料后处理的电解还原脉冲筛板柱

在直径 ５ ｃｍ的电解还原脉冲筛板柱中．研究了板段结构、操作条件、工艺参数及控制方式等对两相流动特性及硝酸铀酸的电解还原性能的影响，开发了电脉冲柱的数学模型。结果表明．在电场作用下，分散相液滴有一定的聚结现象，液泛通量比普通脉冲柱高 ８０％．一般情况下．铀（ＩＶ）产率为 １．５～２．５ ｇ／Ａ·ｂ，电流效率为 ５０％～８０％，肼消耗量为１５％－２０％，叠氮酸和氢气浓度远低于规定的安全限。通过调整有关参数，根据关联式可以方便地估算出所需的４价铀浓度。

Studies on electrolytic reduction pulsed extraction columns for nuclear fuel reprocessing

The basic hydrodynamics and uranium reduction behaviours in 5 cm diameter electrolytic reduction pulsed columns were investigated widely under different column geometry, operating and processing conditions, and the mathematical models to describe the electrolysis process were developed. The hydrodynamic testing of the two phases shows that low voltage dc field influences the coalescence of dispersed phase drops. For the system of 30% TBP (OK)--0.5 mol/L HNO3 the maximum throughputs with the electrical field increased by 80% more than that of normal pnlsed columns without the field. When the uranium loaded in organic phase is re--extracted by electro--reduction, the flooding velocity increases further. The results obtained using natural uranyl nitrate in the electropulsed columns show that the cathode potential, cathode area, temperature, uranium concentration in organic phase and nitric acid concentration in the strip solution have greater influence on uranium reduction efficiency, and the reduction process is controlled by the rate of mass transfer. Based on the theoretical analysis and experimental results, mathematical models were established. The numerical results agree with the experiments quite well.