PUREX流程中Tc(Ⅶ)对U(Ⅳ)反萃Pu(Ⅳ)的影响  

EFFECT OF TECHNETIUM (Ⅶ) ON THE STRIPPING RATE OF PLUTONIUM(Ⅳ) BY URANIUM(Ⅳ) IN PUREX PROCESS

作　　者：张丕禄[1] 齐占顺[1] 朱志瑄[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：《核化学与放射化学》1999年第4期219-227,共9页Journal of Nuclear and Radiochemistry

摘　　要：研究了Tc()对U()还原反萃Pu()的影响。研究结果表明,在单级反萃中,有机相中锝的初始质量浓度高达441mgL时,Pu()的反萃率无明显改变;两相混合放置时间足够长时,Pu()的反萃率会降低,而且开始降低的时间随锝浓度增加而缩短;体系中有机相和水相的酸浓度、Pu浓度、U()及U()浓度的变化在所研究的范围内对Pu()反萃率的影响都不大。逆流萃取的串级实验结果表明,当1BF中Tc()的质量浓度大于135mgL时,会严重影响Pu()的反萃;小于70mgL时,对Pu()的反萃无明显影响。研究还表明,引起Pu()反萃率降低的原因是肼在低价锝的催化作用下的破坏。降低Tc()含量和缩短放置时间都有助于减小PUREX流程中锝对U()反萃Pu()的影响。The influence of heptavalent technetium on the reducing stripping of tetravalent plutonium by tetravalent uranium is investigated.The single stage of stripping experiment is studied first. It is indicated that technetium has no obvious effect on the stripping rate of plutonium when its concentration is high enough to 441 mg/L in the organic phase.The stripping rate of plutonium decreases when the mixing time of two phases is long enough and the time of the stripping rate of plutonium decreased shortens when the concentration of technetium increases.The concentration ranges of the investigation, acid, plutonium, tetravalent uranium and hexavalent uranium have no great influence on the stripping rate of plutonium. The reflux extraction of the cascade experiment is done secondly.The results indicate that technetium has great effect on the stripping rate of plutonium when its concentration is more than 135 mg/L in 1BF. When it is less than 70 mg/L,technetium has no evident effect on the stripping rate of plutonium.The further research indicates that the reason for the decrease of the stripping rate of plutonium is that hydrazine is destroyed by the catalyzing low valent technetium. The decreasing of the concentration of heptavalent technetium and the shortening of the deposited time can minish the effect of technetium in PUREX process.

关 键 词：PUREX流程 铀 钚 乏燃料后处理 锝 反萃取 

分 类 号：TL241.14[核科学技术—核燃料循环与材料]