VVER-440 fuel cycle improvement: status and prospects

The results of development work on the base five-year fuel cycles with second-generation cassettes and average enrichment 4.87% for NPP with VVER-440 are presented. Such power units make it possible to increase thermal power while preserving an acceptable run time and RK-2+ cassettes with an enlarged uranium load for reactor operation at elevated thermal power 107, 109, and 112%. The results of trial commercial operation of third-generation fuel in the No. 4 unit at the Kola NPP in the 23rd load are presented. Increasing fuel enrichment above 5% is a promising direction for improving the VVER-440 fuel cycle. The results of development work on a full six-year fuel cycle with some cassettes kept for the seventh year of operation, which satisfies the operating conditions at elevated thermal power using RK-2+ fuel assemblies with >5% enrichment, are presented.