The effect of the addition of neptunium on the duration of the fuel campaign in the BN reactor

The aim of the work is to evaluate the possibility of using neptunium as fuel for the BN-600 reactor and its subsequent effect on the length of the fuel campaign. To carry out the calculations, neutron physics and thermophysical models of fuel assemblies of reactors were created. Neptunium was added to the main fuel homogeneously in various proportions ranging from 1 to 20% in the form of NpO2 oxide. The characteristics under consideration are the neutron multiplication coefficient in an infinite medium, and the spatial temperature distribution in the fuel element. The homogeneous addition of neptunium to the fuel has a negative effect on Keff. Adding a fraction of neptunium oxide of more than 5% is impractical. The addition of neptunium also had a negative effect on the energy release values, but to a lesser extent. When neptunium is added, the temperature of the BN-600 fuel rods changes by 2-3% at the fuel assembly inlet and outlet.