Transmutation of some actinides and energy production in accelerator driven system using Monte Carlo method

Nuclear waste is created from the operation of nuclear power reactors for the production of electricity. One way to dispose of the waste is to transmute the fuel in an accelerator driven core. The acceleration driven system (ADS) is composed of a natural lead target, beam window, subcritical core, reflector, and structural material. Using a high energy proton accelerator, a spallation neutron source was modeled which was used to drive a minor actinide loaded core. The neutrons are produced by the spallation reaction of protons from a high intensity linear accelerator in the spallation target, and the fission reaction in the core. The simulated high neutron fluxes were used to transmute 237Np, 238Pu, 239Pu, 240Pu, 241Pu, 242Pu, 241Am, 242Am, 243Am in the fuel. It was used a hexagonal lattice for the fuel assemblies. The system is driven by a 1 GeV, 10 mA proton beam incident on a natural lead cylindrical target, 20 cm radius, 70 cm height, and entering the target through a 5,3 cm radius hole. The protons were uniformly distributed across the beam of radius 3 cm. The core is cylindrical assembly, 2,3 m radius, 4,6 m high. The wall thickness of the main vessel is 2 cm. The main vessel is surrounded by a reflector made of graphite, 40 cm thick. The axes of the proton beam and the target are concentric with the main vessel axis. The structural walls and the beam window are made of the same material, stainless steel, HT9.In the calculations, the Monte Carlo code MCNPX, which is a combination of LAHET and MCNP, was used. Continuous energy cross section data at temperature was produced using NJOY99 for input into MCNPX for critical core components. We investigated the following neutronics parameters: spallation neutron yields, energy distribution of the spallation neutrons, heat deposition and transmutation rate of minor actinides.