低浓缩铀辐照后裂片溶液中主要核素对铀形态的影响

项目名称： 低浓缩铀辐照后裂片溶液中主要核素对铀形态的影响

项目编号： No.U1330125

项目类型： 联合基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 刘宁

作者单位： 四川大学

项目金额： 82万元

中文摘要： 以低浓缩铀（U-235≤20%）替代高浓缩铀（U-235≥90%）作为辐照靶分离生产放射性同位素是国际上不可逆转的发展趋势。为此，需要开展大量的相关研究。其中，研究低浓缩铀靶辐照后酸性介质中铀的化学行为以及主要裂片元素对溶液中铀形态的影响既有科学意义，也有强烈的需求背景。本申请课题拟通过理论模拟计算低浓缩铀靶辐照后的总放射性活度、裂变体系的组成以及各主要裂变核素的放射性活度，获得不同富集度铀靶裂变产生的Mo-99、Tc-99、I-131、Nd-147等核素的产额与中子能量等辐照条件的关系。在此基础上，重点研究硝酸介质模拟溶液中U的化学形态及上述裂片元素对U形态的影响，以及U对Mo-99、I-131等核素的形态与化学行为的影响。研究结果可为基于低浓缩铀靶的裂变核素生产、U的回收利用等提供理论指导与技术支持，对低浓缩铀燃料元件在研究实验堆运行中的相关课题以及乏燃料的后处理研究也有借鉴作用。

中文关键词： 低浓缩铀；裂变核素；形态；影响；吸附

英文摘要： It is an irreversible trend to reduce or eliminate highly enriched uranium (HEU, 235U≥90%) fuel and encourage the use of low-enriched uranium fuel (LEU, 235U ≤ 20%) in related nuclear processes, since it can prevent nuclear proliferation and terrorist activities, as well as ensure the stable supply of medical isotopes, such as Mo-99 in the world,. However, there are much research issues should be investigated. Of which, the chemical behavior of uranium in acidic solutions after irradiation of low-enriched uranium targets and the effects of major fissile nuclides on chemical speciation of uranium are very important and are reported little at home and abroad. This project try to create a theoretical model to calculate the total radioactivity in the irradiation of uranium targets, to calculate the major fissile nuclides radioactivity，and to obtain the relation to fission yield and energy of key fissile radionuclide, such as Mo-99、Tc-99、I-131、Nb-147 in different enrichment uranium targets and incident neutron energies. After then, the chemical behavior of uranium in low-enriched uranium solution on acidic medium and influence in the critical radionuclide to form of uranium, as well as the chemical speciation and behavior of several fissile nuclides, such as Mo-99, I-131 in a large number of uranyl ion would be inves

英文关键词： low-enriched uranium；fissile nuclides；chemical speciation；influence；adsorption