The U-232 production in thorium cycle

The main problem of Th-232 and U-233 mixture as a reactor fuel is that it contains the admixture of U-232. The decay chain of U-232 produces penetrating gamma rays. The concentration of U-232 as a function of burnup, different kinds of a coolant and average neutron energy are investigated. The main channels of production and destruction of U-232 are presented. The assembly that was used in this paper is a critical reactor which makes it possible to change volumes of fuel and coolant. One can obtain the minimal value of U-232 saturation concentration using Pb-208 coolant and the maximal value of the critical burnup together. The calculations were carried out using MCNP6.1/MCNPX 2.7 codes and the analytical model.