Study onkey core design parameters of axial traveling wave reactor

By using a typical Traveling-Wave reactor (TWR) core model formed by hexagonal assemblies, this paper studied the performance of different types of fuel enrichment, coolant and nuclear fuels, which were loaded respectively in this TWR model for a long time operation, and analyzed the key design parameters of an axial TWR core. The results indicated that, in the case of same assembly and core geometry parameters, there was an equilibrium fuel enrichment, at which the change of core reactivity was small. Also, when the core were loaded by different coolant, the core rectivity of plumbum-208 was the largest, followed by plumbum and bismuth alloy, nature plumbum and sodium. In the case of same geometry and similar initial reactivity, the burnup reactivity loss of metallic fuel was the smallest, followed by carbide fuel, nitride fuel and finally oxide fuel. Therefore, in order to meet the small reactivity fluctuations, equilibrium fuel enrichment, plumbum-208 and metallic fuel are recommended to design a new TWR. The calculation result also showed that the performance of axial TWR after stability was only relation to the material in fresh fuel region and not relation to the length and fuel enrichment of startup region. (authors)