Upgrading of the core calculation modules of KARATE-440

The KARATE-440 core calculation program developed by KFKI AEKI simulates the coupled neutronic and thermohydraulic processes in the VVER-440 core under startup, normal and slow transient conditions. Recently a new version of core calculation modules of KARATE-440 has been worked out. The main goals of the developments are the following: The more precise description of the control rods; Upgrading the libraries with the new fuel types; Preparing better links to some code package which is used in core design and safety analysis (KIKO3D). The efficiency of the new code system is presented by comparison of the calculated linear power distribution in the vicinity of the coupler prepared by MCNP and the KARATE-440 code. The capabilities of the code are illustrated with typical validation results (control rod efficiency, boron let down curve). (author)