RZA program complex for multigroup two-dimensional calculation of a reactor in the ranges of neutron slowing-down and thermalization taking into account burnup

Methods for multigroup calculation of neutron physical reactor characteristics containing strong shielding burnable poisons are described in two-dimensional (R, Z)-geometry. The calculation consists in two main stages: the first one is the calculation including burnup of heterogeneous cells characterizing physical reactor cores; the second - the proper calculation of the reactor on the basis of homogenized macro- and micro cross sections obtained during cell calculations. Cell calculation is carried out by DS-method. To solve the equations describing change in the isotope composition, the combination of Runge-Kutta and Adams methods are used. ''Through'' calculation of spatial energy distribution of neutron flux density in the region of deceleration and thermalization is carried out at P1 or diffusion approximations. Spatial distribution of neutron flux density in every energy group of the reactor is determined by means of the effective modification of the method of variable directions. Constant soft ware is built on microconstat libraries: 21-group in the region of thermalization