Year
2012
Abstract
In the past few years, efforts for the development of new measurement systems in the area of nuclear nonproliferation and homeland security have increased substantially. Monte Carlo is one of the methods of choice for the analysis of data from existing systems and for the design of new measurement systems; it allows for accurate description of geometries, event-by-event detection procedures, and particle interactions by detailed representation of the appropriate physical processes. This paper describes the use of the Monte Carlo code MCNPX-PoliMi ver 2.0 for nuclear nonproliferation applications, with particular emphasis on the simulation of nuclear fission. In fact, of all possible neutron-nucleus interactions, fission is the most representative of special nuclear material, i.e., U-235 and Pu-239, the material of interest in nuclear nonproliferation applications. MCNPX-PoliMi ver 2.0 is based on MCNPX ver. 2.7.0 and is the new release that has evolved from MCNP-PoliMi, which was released from the Radiation Safety Shielding Information Center (RSSIC) at Oak Ridge National Laboratory in 2003. In April, 2012, MCNPX-PoliMi ver. 2.0 was released through RSICC as a patch to MCNPX ver. 2.7.0 and as an executable. In the paper, simulation results for scenarios of interest are discussed and, where possible, comparisons with experimental data are made.