Abstract
The determinant role of raw uranium usage for atomic power production in the twenty-first century is shown. The limitations of modern reactors are the low fission materials breeding in thermal reactors and the large amount of uranium needed for start-up of fast reactors. Thermal reactor breeding can be increased under the following conditions: a decrease in the neutron losses in structural materials, leakage and operative control, and the use of a closed balanced fuel cycle. In this case, some of the raw 235U in the fuel at the start of the campaign decreases. Replacement of the raw 235U by 233U produced from thorium increases the raw usage up to 100%. The yield of 233U in a fission reactor decreases the burning-out. Production of 233U by a tokamak-based volumetric neutron source (VNS) removes the burning-out limitation. In this case, the energy consumed by the VNS is much less than the gain in the fission reactor energy production.