Results Three-Dimension Hexagonal Dynamic Benchmark Problems for VVER Type Reactors

A series of three-dimensional hexagonal dynamic benchmark problems have been defined during 1992 - 1994 in the international VVER cooperation forum AER. All three problems are asymetric control rod ejections from low power level in a realistic VVER-440 core with fuel of three different enrichments and given nuclear data. However, the complexity of the models needed in the benchmark solutions is continuosly increased beginning from pure reactor kinetics and extending to real core thermal hydraulics modelling with a hot channel and DNB effects. Solutions calculated by six organizations with five different mostly nodal codes are included. Agreement of neutron kinetics results is very good. More differneces are induced by thermal hydraulics modelling.