羟基脲还原Pu(Ⅳ)和在U/Pu分离中的应用研究  

Pu(Ⅳ) Reduction With Hydroxyurea and Its Application in U/Pu Separation

作　　者：朱兆武[1] 何建玉[1] 章泽甫[1] 宋天宝[1] 张宇[1] 郑卫芳[1] 

机构地区：[1]中国原子能科学研究院放射化学研究所,北京102413

出　　处：《原子能科学技术》2004年第4期306-311,共6页Atomic Energy Science and Technology

摘　　要：研究了在 3 0 %TBP/煤油和HNO3 水溶液混合相中羟基脲 (HU)还原Pu(Ⅳ )的动力学。研究表明 :HU可还原Pu(Ⅳ )到Pu(Ⅲ ) ,混合相中的还原速率方程可表示为 -dc(Pu(Ⅳ ) ) /dt=kc(HU)·c- 3 2(HNO3 )c2 mix(Pu(Ⅳ ) )c- 1mix(Pu(Ⅲ ) ) ,其中 ,k为速率常数 ,15℃时 ,k =( 896± 5 9)mol2 3 ·L- 2 3 ·min- 1。以HU作Pu(Ⅳ )的还原剂 ,用离心试管模拟了Purex流程 1B槽中的U/Pu分离 ,进行了 16级逆流串级实验。串级实验中 ,U中去Pu的分离系数达 5 4× 10 4 ,Pu中去U的分离系数为 1 8× 10 5,每kgU产品中的Pu含量约为 11μg。The reduction of Pu(Ⅳ) with hydroxyurea(HU) in the mixed phase of 30%TBP/OK-HNO_3 system was studied. The study results show that HU can reduce (Pu(Ⅳ)) to Pu(Ⅲ) and the reduction rate can be expressed as -dc(Pu(Ⅳ))/dt=(kc(HU))c^(-3.2)(HNO_3)c^2_(mix)(Pu(Ⅳ))c^(-1)_(mix)(Pu(Ⅲ)), where k is the rate constant, and k=(896±59) mol^(2.3)·L^(-2.3)·min^(-1) at 15 ℃. With HU serves as a reductant, 16 stages count-current cascade experiment was performed using centrifugal tube to simulate U/Pu separation in the 1B contactor of Purex process. The separation factor of Pu from U and the separation factor of U from Pu reach to 5.4×10~4 and 1.8×10~5, respectively. The amount of Pu is about 11 μg in per kg U product.

关 键 词：羟基脲 铀钚分离 分离系数 还原剂 PUREX流程 

分 类 号：TL241[核科学技术—核燃料循环与材料]