Finite-Difference Fine Mesh 2D Calculations of Neutron Fields in VVER Reactors Using Full Sets of Multigroup Cell Characteristics Obtained with the MCU Package
25th Symposium of AER on VVER Reactor Physics and Reactor Safety (2015, Balatongyörök, Hungary)
Advances in spectral and core calculation methods
Abstract
MCU code make it possible to tally the sets of functionals, which can be interpreted
as an average cross-sections and diffusion coefficients over choosen subvolumes of reactor
core. Finite-difference calculations with these sets of cell characteristics can be then compared
with benchmark Monte Carlo ones, thus producing reliable information on operative code
quality. As an example of analysis of the kind Monte Carlo results are compared with 1-, 2and 4- groups 2D mesh calculations of VVER-1000 core. Surrounding of the core, such as
baffle, vessel and the like is covered by one row of fictitious fuel assemblies to avoid usage
of rather artificial boundary condition as neutron flux logarithmic derivative. The attempt also
was made to calculate with mesh algoritm equilibrium xenon distribution throughout the
core.