Advantages of VVER-440 fuel cycles with new fuel assemblies

Throughout the existence of VVER-440 reactors; their fuel design was always subject to ongoing improvements. By the moment, extensive computations and RD&D have been performed to evaluate the feasibility of farther improvement of VVER-440 fuel cycles and fuel design. This paper discusses computational assessments of basic neutronic parameters of prospective fuel cycles based on newly-designed fuel assemblies, namely RK3+, slim rod and RK3+SR. RK3+ stands for shroud less fuel assemblies with wide angle bars instead of shrouds and optimized pitches between fuel rods Slim Rod means shrouded fuel assemblies with rods whose external diameter was reduced to 8.9 mm. RK3+SR is an abbreviation for shroud less fuel assemblies with wide angle bars instead of shrouds and rods whose external diameter was reduced to 8.9 mm. This paper demonstrates that, in the countries operating VVERs-440, a transition to new fuel design would improve both the energy output and the fuel cycle economy.