Evaluation of the Possibility of Using the Full Load of MOX Fuel in the VVER-600 Reactor

In this paper, we analyze the possibility of using 100% MOX fuel (mixed oxide uranium-plutonium fuel) in a VVER-600 reactor with nominal power of 1600 MW(t). The VVER-600 core consists of 163 fuel assemblies (FAs) similar in design to VVER-TOI fuel assemblies. MOX fuel contains tailings of uranium (99.8% 238 U and 0.2% 235 U) and a mixture of plutonium isotopes. A campaign with uranium oxide (UOX) fuel is also modeled to compare the neutronic characteristics with those of the MOX variant. For both MOX and UOX options, the efficiency of fuel use is analyzed at an increase in the water/fuel ratio (W/F) in comparison with the base case. The W/F ratio increases in three ways. For calculated estimates, the KASSETA-BIPR-7 software package is used. The results of calculations of individual neutronic characteristics with 100% MOX fuel when modeling the VVER-TOI variant with power of 3300 MW(t) are presented to compare with the results of calculations using other independent codes.