Design Of A High Flux Epithermal Reactor Core And The Reaearch On Transmutation Of Long-lived Nuclear Waste

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.