Purex流程以N_2O_4调节钚价态的研究

STUDY ON ADJUSTMENT OF Pu VALENT STATE BY N_2O_4 IN PUREX PROCESS

摘要: 详细描述了用液体N_2O_4调节Purex流程 1BP、2BP、3BP和4W 料液中 Pu(Ⅲ)价态的实验结果。研究酸度、钚离子浓度、铁离子浓度和温度等因素对N_2O_4氧化调价的影响。实验结果表明,N_2O_4氧化 NH_2OH、N_2H_4和 Pu(Ⅲ)-N_2H_4-NH_2OH的速度很快,在实验条件下是瞬间反应;在Pu(Ⅲ)-U(Ⅳ)-N_2H_4-HNO_3体系中,钚离子有明显的催化N_2O_4氧化 U(Ⅳ)的作用;模拟 Purex 流程 1BP、2BP和 3BP料液,用 2.5倍化学计算量的 N_2O_4,10—15℃下 20min,可以达到 Pu(Ⅲ)完全氧化到 Pu(Ⅳ);调价后的料液放置 5d,Pu(Ⅳ)的含量没有变化。

Abstract: The effects of the concentration of Pu(Ⅲ), temperature, acidity etc. on adjustment of Pu valentstate by N_2O_4 are studied. The experimental results show that the oxidation rate of NH_2OH, N_2H_4 andPu (Ⅲ)--NH_2OH--N_2H_4 is faster and the reaction is instantaneously completed at given experimental con-ditions. In the system of U(Ⅳ)-N_2H_4-HNO_3, the oxidation rate of U(Ⅳ) increases with the increaseof Fe(Ⅲ) concentration. In the system of Pu(Ⅲ)-U (Ⅳ)--N_2H_4-HNO_3, plutonium ion has similarcatalytic effect as Fe(Ⅲ). Simulating feed 1BP, 2BP and 3BP in Purex process, Pu(Ⅲ) may be oxi-dized to Pu(Ⅳ) completely with 2.5 fold stoichiometric amount of N_2O_4 at 10--15℃ for 20 min.