【作者】 赵伟；

【导师】 刘滨；

【作者基本信息】 华北电力大学（北京） ， 核反应堆物理与安全， 2011， 硕士

【摘要】 随着核电事业快速发展,核能安全利用受到普遍关注,核电站乏燃料后处理(尤其是长寿命放射性锕系核素后处理)成为解决核电发展瓶颈的关键技术。目前分离-嬗变技术成为国际上解决乏燃料后处理的研究热点,而嬗变技术主要研究对象是热堆、快堆和加速器驱动次临界装置。本课题主要研究热中子堆嬗变技术,在结合已有的成果基础上,提出高通量超热中子堆嬗变方案,通过蒙特卡洛程序(MCNP)对稠密栅棒型热堆、快堆和高通量超热中子堆三类堆芯进行建模,对其中子物理特性和嬗变锕系核素能力进行对比研究,并分析了高通量超热中子堆芯加入锕系核素后堆芯反应性、中子能谱及中子通量密度的变化情况。本文对稠密栅棒型热堆和快堆的嬗变性能也进行了比较,同时对核电发展现状,我国锕系核素累积趋势,先进核燃料循环体系,分离-嬗变技术发展及现状,蒙特卡洛方法原理及涉及的中子物理计算等方面理论进行了阐述。本文得出主要结论有：1)MA核素在中子通量密度达到1016n/cm2·s数量级超热中子堆中具有较好的嬗变效率,其裂变比优于快堆和稠密栅棒型热堆,具有更好的中子经济性；2)快堆比稠密栅棒型热堆具有更好的嬗变效率和中子经济性；3)热堆、快堆和超热中子堆加入MA核素后,堆芯中子能谱都有硬化现象,超热中子堆内中子通量密度出现不均匀化趋势,在嬗变区内中子通量密度有一定提高。本文所得出的数据和结论将对我国乏燃料的后处理及嬗变技术研究具有-定的意义和价值。更多还原

【Abstract】 With the rapid development of nuclear power industry, people pay more attention to the safe and effective use of nuclear energy, especially, the safe disposal of spent fuel. The recycle of the long-lived radioactive actinide nuclides in the spent fuel is the key technology to avoid the long-term radiological hazards of spent fuel. The partitioning and transmutation is widely accepted technology post-process of nuclear fuel. The research on transmutation technology of the actinide nuclides in the spent fuel is focused on fast reactors, thermal reactors and the accelerator-driven system.In this paper, we mianly focus on transmutation technology of thermal neutron reactor, we used MCNP code design three different transmution reactor core based on existing research results to study the transmution charactistics of MA, the three reactor cores are tight lattice thermal reactor core, fast reactor core and the high flux epithermal reactor, then we compared the neutron econmy and and transmutation efficiency of the three different reactor cores. We also discussed the changes of reactor core reactivity, neutron spectrum and neutron flux density of high flux epithermal reactor core after adding actinide nuclides to the reactor cores.The comparison results of the transmutation characteristics between tight lattice thermal reactors and fast reactors were listed in this paper. Meanwhile, the current research situation and development of the partitioning and transmutation technology, the cumulative trend of actinide nuclides were also discussed.Based on our simulation calculations, we obtained three important conclusions. Firstly, the MA nuclide transmutation efficiency of the high flux epithermal reactor is better then other two type of reactors when neutron flux density up to the magnitude of 1016n/cm2·s, the fission ratio and neutron economy of high flux epithermal reactor are also better then that of the fast reactor and tight lattice thermal reactor. Secondly, compared with the tight lattice thermal reactor, the transmutation efficiency and neutron economy of fast reactor are better. Finally, after thermal reactor, fast reactor and the high flux epithermal reactor adding MA nuclides, the neutron spectrum of each core is harden. In short, the data and conclusions given in this paper would provide a reference for the further research on the transmutation technology and the post-process of spend fuel in our country.更多还原