VALIDATION OF MONTE CARLO CODE MCNPX FOR STUDIES ON NEUTRONS PRODUCTION IN THE SPALLATION REACTION

Transmutation of plutonium and minor actinides in accelerator-driven systems (ADS) is being envisaged for the purpose of reducing the long-term radiotoxic inventory of spent fuel nuclear reactor. The target is the physical and functional interface between the accelerator and the sub-critical reactor in the ADS, so it is probably the most innovative component of the ADS. The performances of ADS are characterized by the number of neutrons emitted per incident proton, the mean energy deposited in the target for neutron produced, the neutron spectrum, and the spallation product distribution. Neutron multiplicity is the number of neutrons produced per one beam particle. The present paper focuses on the production of neutrons in the spallation reactions. The neutrons produced in spallation reactions can be characterized by their energy and spatial distributions and multiplicity. This paper focus on the validation of Monte Carlo code (MCNPX) [1, 2] for study of neutrons production in the spallation reaction. Monte Carlo simulations have been performed to investigate the neutron multiplicity as a function of energy of incident proton beam, also as a function of target material and target size. Neutrons spatial distributions at target are calculated and compared in different target materials and proton energies. The comparison between present calculated and the measured of neutron multiplicity revealed fairly good agreement.