On few-groip program application for calculating integral characteristics of fast neutron fields

The applicability of the few-group NEGA (leakage and diffusion method) and CUB-2 (method of neutron leakage integration over a source volume) programs for calculating neutron field integral characteristics in multilayer shields typical for water cooled nuclear reactors is investigated. Calculation results are compared with the data of measurements performed by means of the threshold detectors on the base of 115In (n, n') and 193Hg (n, n') in an experimental room of the research reactor and with that of the three-dimensional calculation according to the FASTER program. The conclusion is drawn on the applicability of the considered programs for calculating the neutron flux integral densities at energies exceeding 1 MeV in metal and water multilayer shields with attenuation ratio up to 1010 times