Shielding Properties Of The Shell Of The New Spent Fuel Dry Storage Containers

The current international and domestic nuclear power plants mainly use nuclear fission reactions to generate electricity, fuel loading in the reactor must be kept (or greater than) the critical mass to maintain continuous operation of nuclear reactors, it must remain installed in the pile of fissile material often holding (or greater than) the critical state, it is impossible to produce a chain reaction. Rated power to be issued within a certain period of operation, it is necessary to maintain the reactor critical mass of material, having a back-up so that the reactor core reactivity.When burn-up fuel reaches a certain depth, due to the generation and accumulation of fission product poisoning effect of fuel consumption during operation and when the reserve reactive near extinction, even though there are a considerable number of fuel elements in the fissile fuel, it must be its unloaded from the heap, change into new fuel. The fuel elements are discharged spent fuel.In the spent fuel, accounting for3%of the quality of the material is uranium-235and plutonium-239fission products and the products of their indirect decay chain. Although these substances are considered to be high-level radioactive waste, but because they themselves also contain a considerable amount of material is a medium-to long-term radioisotopes, such as strontium-90, cesium-137and iodine129, such as technetium-99. If not handled properly, it will seriously affect access to these high-level radioactive waste people’s health.Currently on the way into wet storage of spent fuel storage and dry storage in two ways. That is, wet storage of spent fuel discharged from the reactor components directly stored in the pool, because the wet storage has several advantages:(1) water having good thermal conductivity, the thermal decay is conducive to export;(2) can be effectively shielded ray;3transparency characteristics. Dry storage is to use the spent fuel storage containers to store the spent fuel assembly, which has the advantage of:(1) to provide flexible storage capacity;(2) shorten the construction period;(3) No corrosion, reducing maintenance costs;(4)use of natural air cooling without fear because of the loss caused by power or cooling capacity of the cooling water interruption;(5) generates less secondary waste during storage, no water purification problems.The current world’s most advanced reactor type nuclear reactors developed by the U.S. company Westinghouse AP1000reactor type. AP600AP1000is based on the use of nuclear passive safety concept designed a new type of Reactor type. The current international and domestic nuclear power plants in operation burn-up spent fuel produced mostly in45GWd/tU, while currently widely used in foreign spent fuel dry storage containers, such as MC-10, TGC-36, NAC-C28S/T and other models are designed for existing nuclear power plants generated a relatively low burn-up spent fuel, can not save up60GWd/tU AP1000fuel consumption of this new type of reactor spent fuel generated, so for this kinds of needs, research and designed a new type of spent fuel dry storage containers.This article describes the research design process, the new test results photon shielding materials research and spent fuel storage container housing shielding performance. In the design of the shielding material, basically completed the design goals:research and design a new type of photon shielding material has structural and functional integration, reducing the strength of the shell material in the structure and performance requirements, but through the use of test MCNP code, which shielded the results achieved on the safety of nuclear radiation dose rate around the container requirements, completed in the case of smaller quality meets and exceeds the shielding effect of the foreign like product requirements. The system cost, and achieve a lower cost of production without reducing the shielding effect in the case of the purpose.