Rearch On Thorium Self-sustaining Cycle And Thermal Characteristics

The energy problem is one of the most people concern, with the rapid development of the nuclear power, the demand of nuclear fuel uranium will become more and more bigger, but natural uranium resources is very limited, thorium as can be converted into the nuclear fuel resources, is a potential resources for development of the nuclear power.March11,2011Japan fukushima nuclear accident caused a global nuclear power security concern.Compared with uranium fuel cycle, thorium fuel accumulated fission products are low toxicity and produce long life actinide elements in less number; nuclear non-proliferation ability is stronger;233u have good neutron performance, and has higher conversion ratio CR.Therefore, the use of thorium fuel can reduce nuclear waste disposal cost, at the same time solve the shortage problem of nuclear fuel and so on.Use thorium fuel in TACR1000,not only can realize thorium uranium self-sustaining cycle, but also save the uranium fuel.Therefore, it can consider the mixed-use thorium fuel and uranium fuel in the reactor design.However, it is different in performance between thorium fuel and uranium fuel,in order to realize the thorium uranium self-sustaining cycle, and at the same time, it is sure the safe operation of the reactor, it need to reseach and analysis on use thorium fuel in TACR1000.The realization of thorium uranium self-sustaining cycle and meet its physics and thermal-hydraulic requirements, it is an important question in the thorium uranium fuel recycling.(Th-U)O2CANFLEX43fuel bundle includes two types of fuel elements, the ThO2elements in the inner two rings and the slightly enriched uranium (SEU) elements in the outer two rings as driving fuel rods. The four driving schemes are introduced in this paper based on different enrichment and power density of drive fuel rods. The neutronic physics calculation by DRAGON Program and the thermal-hydraulic analysis are executed. Obtaining realize more reasonable drive model of thorium uranium self-sustaining cyclein the TACR1000:at1.4%enrichment of233U, the fuel consumption is16MWd/kg; the233U production is5.9872g; the highest surface temperature of the fuel rod cladding is371℃; temperature in the fuel rod center is183℃; and the maximum flow in the single channel is25.4kg/s. These parameters meet the requirements of thorium uranium self-sustaining cycle.Through the analysis of spent fuel,the accumulation of fission products in reactor has low toxicity and the long life actinide elements in quantity than uranium fuel less, therefore, the development of thorium base reactor is a very promising reactor.