The computational codes use numerical solutions of the transport equation and different geometries and approxi-mations: TRIGEX [2] - three-dimensional geometry, diffusion approximation; SUSD3D [3] - three-dimensional geometry,Sy-method; TSUNAMI package of the SCALE system [4, 5] - one-, two-, and three-dimensional geometries; method ofdiscrete ordinates, method of short characteristics, and Monte Carlo method.