New methods development for SCORPIO-VVER core monitoring systems to address advanced VVER 440 fuel types

With the introduction of advanced design fuel with the Gd burnable absorber to Czech and Slovak VVER 440 reactors, the SCORPIO-VVER core monitoring system (CMS) faces new requirements and challenges. New methodology and tools had to be developed in the area of core design (neutron physics, core thermal hydraulics and fuel thermal mechanics) to properly model and address new design features of Gadolinium bearing fuel of Gd 1 and Gd 2 type. These methods have to be adapted for implementation in SCORPIO-VVER CMS. The paper provides a comprehensive list of requirements and open questions that need to be properly addressed and clearly defined prior to starting any major system innovation. Validation of a simplified simulator for the HiBu domain is under development using FEMAXI code and new 2D-3D tool development for the CEZ utility. Conclusions of the paper concentrate on mid-term and long-term innovation plans for core and fuel operation reliability systems