Calculation of hybrid ADS systems (accelerator + target + blanket) by using different descriptions of initial neutron source

In this paper the comparative analysis of some schemes of physical calculation of hybrid nuclear systems “accelerator + blanket + target” with usage of the codes for the nucleon — nuclear cascade calculation and the neutron transport codes LAHET (USA), PARSE-2 (Russia) and the reactor code MCNP (USA) is given. The full protons — neutron calculations are compared to the neutron reactor calculations, in which the external neutron source is formed on the basis of calculation of primary neutrons of the intranuclear cascade (“spallation” neutrons). The calculations are fulfilled for the model of sub-critical reactor system with plumbum-bismuthic heat-transfer and with dioxide of uranium as fuel earlier developed in Keldysh Institute of Applied Mathematics. It is shown that for achievement of acceptable accuracy (2% – 3%) in calculation of such important characteristic, as distribution of energy release over volume of blanket, the source of external neutrons in the reactor codes should be set with high bound on energy up to 20 Мэв.