The U-th Fuel Self-sustaining Cycle

It is important to solve the problem about the lack of nuclear fuel that finding an efficient approach to exploit Th fuel.By contrast with Once-through fuel cycle,U-Th closed fuel cycle is of benefit to the using of U and Th resources.If U-Th self-sustaining cycle could be achieved,we can make use of Th resources without fissionable materials.The paper introduces the current condition of fuel cycle,and analyzes the features,mode and current condition of U-Th fuel cycle.At last it expounds the importance of U-Th self-sustaining cycle.We calculate the different projects of U-Th fuel cycle by 3-D MCCOOR code system,which consists of three standard programs:MCNP,COUPLE and ORIGEN-S. It can be applied to burn-up calculation of reactor with 3-D geometry structure and research on power distribution of reactor.The paper makes a particular research on the possibility of the ²³³U-²³²Th self-sustaining cycle in CANDU.At first,we choose the mixed bundle approach, dispose U and Th fuel together in bundle and then probe in the accumulation of ²³³U preliminary.Secondly we study the approach of ²³³U-²³²Th self-sustaining seriously, which indicates that a feasible ²³³U-²³²Th self-sustaining cycle could be achieved in CANDU with an asymmetrical distribution in radial in bundle.Moreover,we make a research on the influence of five factors:fuel enrichment,distribution of enrichment, fuel order,power density and refrigerant on U-Th self-sustaining cycle.The paper gives a contrastive analysis about models and then demonstrates a feasible theory model of ²³³U-²³²Th self-sustaining cycle in CANDU,which provides theoretical evidence for the exploitation of Th fuel...