[en] The GETERA code is intended for calculation of neutron space-energy distribution in nuclear reactor cells and polycells and various neutron flux functionals by the collision probability method in multigroup approximation. The code uses the 26-group BNAB nuclear data library for slowing down diapason. In the 0 to 2.15 eV thermalization range the code uses a special 100-group neutron cross-section library based on the ENDF/B-IV and JENDL-2 evaluated nuclear data files

[en] It is apparent that serious attention must be given to the use of weapons-grade plutonium in fuel cycles in nuclear power plants. It is becoming increasingly necessary to organize a mixed fuel cycle which would be presumed to have ordinary, low-enriched uranium fuel and weapons-grade plutonium fuel in a one-time reactor core loading. This research examined the problem of how to detect the possible substitution of a low-enriched uranium bundle for a bundle containing weapons-grade plutonium. Final determination of fuel assembly substitution was made using a non-destructive control methodology, which was based on gamma-spectra analysis of spent fuel for initial fuel composition identification

[en] The possibility of decreasing the vapor fraction at the VVER-1200 fuel assembly outlet by shaping the axial power density field is considered. The power density field was shaped by axial redistribution of the concentration of the burnable gadolinium poison in the Gd-containing fuel rods. The mathematical modeling of the VVER-1200 core was performed using the NOSTRA computer code.

[en] The problem of the use of burnable absorbers (BAs) in VVER-type reactors is considered to reduce the volume of “liquid” regulation of excess reactivity margin for fuel burnup. As such, natural gadolinium and europium are considered in the form of Gd₂O₃ and Eu₂O₃, placed in integrated form with uranium fuel in fuel rods. The ratio of fuel rods with BAs and conventional fuel elements is 1:6. Variants of both the homogeneous location of the BAs and heterogeneous, including for the mixed use of these BAs were considered. The strong influence of the BAs composition and their location in the fuel elements on the dependence of the multiplication factor on fuel burnup is shown. (paper)