The Basic Research on the Formation of the Neutron Irradiation Field for the Minor Actinides Transmutation

本研究是对微量锕系元素嬗变的基础性研究。在不同中子谱的辐照场中，通过测量微量锕系元素与铀的相对核裂变率比，找到微量锕系元素嬗变所需的适当中子场。实验是在kua的固体慢化核中用聚乙烯慢化高浓缩铀核进行的。为了系统地改变中子场的中子谱，系统地改变了堆芯的H/<235>^U比。本研究采用三个核心；这些核分别被命名为EEE1、E1和e3核。用活化箔法对中子谱进行了计算和实验评价。裂变速率比的测量是用轨道蚀刻探测器进行的，该探测器安装在一种特殊的辐照装置中，用于替代背对背式双裂变室。靶上有效原子数的比值也采用了轨迹腐蚀探测器。这与之前报道的13∶1中原子数<237>^ Np与^<235>U之比的值一致。在E1核的中心，测量值<237>^Np/<235>^U的裂变率比为0.016，比之前报道的值小30%左右。其他核心的数据分析正在进行中。

This study is a basic research on transmutation of minor actinide. By measuring relative nuclear fission rate rations of the minor actinide to the uranium in the irradiation fields, which have different neutron spectrums, it is to find that of adequate neutron field for transmutation of the minor actinide.Experiments were performed using polyethylene moderated, highly-enriched uranium cores at a solid moderated core in the KUCA. In order to systematically vary the neutron spectrum of the neutron field, the H/<235>^U ratio of the core has been systematically varied. Three cores were employed in this study; those cores were designated as EEE1, E1 and E3-core respectively. The neutron spectrum was evaluated in both of calculation and experiment using activation foil method.The fission rate ratio measurements have been performed using track-etch detectors put in a special irradiation apparatus used for the alternative of the back-to-back type double fission chamber.The ratio of the number of the effective atom on the target also used the track-etch detectors too. This agrees with the previous report value on the ratio of <237>^ Np and ^<235>U number of atoms in 13 : 1. At the center of the E1 core, the measured value of <237>^Np/<235>^U fission rate ratio was 0.016 is smaller than the previous report value about 30%. Data analysis of other core is now being performed.