Possibility of Building a Thermal Nuclear Reactor with Total Utilization of the Initial Uranium and Thorium

Abstract

It is shown that total utilization of the natural stocks of uranium and thorium is possible in thermal nuclear reactors. The technology is based on eliminating parasitic neutron absorption in ¹³⁵Xe, using cyclic operation of the fuel elements in the reactor. In addition, neutron losses in the production chains of fissioning materials are smaller and fissioning materials, especially ²³³U, are put into active operation more quickly. The advantages of cyclic transposition can be fully realized by using the core superposition method. In this method, the excess neutrons from a part of the core where the reactivity is positive are directed into a zone with a high breeding ratio and negative reactivity.

Fuel based on natural uranium permits using up to 18% of the initial material with recycling. Adding more than 20% ²³²Th to the initial material permits total utilization of ²³²Th and ²³⁸U in the recycling regime.