Variational nodal expansion method. Extension to three-dimensional cartesian geometry, and benchmarking with mox fuel

SCORPIO-VVER system was implemented at Unit 1 of NPP Dukovany in 1998. Input and output data were recorded and analyzed during more than 5 months of operation. The results are used for determination of the quality of measurements and the precision of calculations provided by the system. Comparison with the results of the other systems working at NPP is performed as well. This paper describes the determination of quantities which are important for on-line analyses and for the operator's interface. Calculations of the basic reactor and primary circuit parameters are presented including comparison of results with outputs of other systems. The method of the 3D power distribution determination in reactor core is discussed and examples of results are presented in comparison with the output of the VK3 system and independent calculations (author) (ml)