A theoretical study of heavy water - minor actinide blankets for proton accelerator transmutation

Nuclear fission is the only reaction leading to actinide transmutation. In an accelerator based assembly, employing heavy water solution circulation actinides are almost permanently exposed to a high neutron flux. The actinide supply from the spent fuel elements of nuclear plants is balanced with removing fission products from the transmutation system. In the process of incineration in the hybrid water assembly there occurs a state when actinide concentrations do not change in time. It is in a steady state that the likely regimes of irradiation and transmutation performance of the system are studied. The fissions of the short-lived nuclide 238Np dominate in high level neutron fluxes, while in routine level fluxes it is the fissions of 239Pu that are dominant. It i shown that the transmutation performance depends on an acceptable energy deposition density rather than the type of the loaded actinide waste. (author) 13 figs., 3 tab., 5 refs