The design of accelerator-driven sub-critical fission machines as MYRRHA requires powerful simulation tools for the modelling of high-energy cascade and of the neutron source production through various processes and for the transport of the produced neutron and other particles. The paper report the Monte-Carlo numerical simulations made to assess thoroughly the MYRRHA ADS core pre-design using MCNPX 2.5.e, a beta-version of the multi-particle MCNPX transport. The main neutronics characteristics of MYRRHA ADS are presented, namely the external (non-fission) neutron source, the fission multiplication factors, the various power and flux distributions in the sub-critical core, neutron spectra, the proton and neutron-induced DPA damage and helium gas production inside the spallation target steel shell. The presented results are selected with the aims to highlight the strength of the MCNPX code as dedicated computational tool for the design and operational calculations of hybrid machines such as ADS. Thanks to many new capabilities amongst other the “mix-and-match”, the lattice tally and the mesh tally, the code is shown to be a tailor-made powerful tool for carrying out numerical simulation of accelerator-driven systems. The inability of the code to yield accurate local power values in those sub-critical fission machines is pointed out as the main weakness of the code. This is chiefly due to the missing of delayed energy release. A troublesome behavior has also been pointed out as the MCNPX F6:n and energy deposition mesh-tally type 1.
|Title of host publication||Strength and Weakness of MCNPX: Experience Gained from MYRRHA ADS Calculations|
|Place of Publication||LaGrange Park, IL, United States|
|State||Published - 17 Apr 2005|
|Event||Monte Carlo 2005 Topical Meeting - The Monte Carlo Method: Versatility Unbounded in a Dynamic Computing World - Chattanooga, Tennessee|
Duration: 17 Apr 2005 → 21 Apr 2005
|Conference||Monte Carlo 2005 Topical Meeting - The Monte Carlo Method: Versatility Unbounded in a Dynamic Computing World|
|Period||2005-04-17 → 2005-04-21|