Transmutation of fission products and transuranium by high energy neutron

We discuss the feasibility of systems that incinerate radioactive products (FP) and transuranium (TRU) by using high energy neutrons. As high energy neutron sources, μCF reaction, fusion reaction, and spallation reaction were investigated. In the system that utilizes μCF reaction, a subcritical core made of FP and TRU is bombarded by 14 MeV neutron generated via μCF reaction. Monte Carlo neutron transportation code (MCNP) and evaluated nuclear data (ENDF/B-VI) were used to simulate neutron transportation in the core. To generate μ-mesons, a 4 GeV-25 mA deuteron accelerator is used. The results of the simulation show that the driver energy can be completely supplied by transferring fission energy to electric energy; to operate this system, no energy is required. As the system that utilizes an inertial fusion reaction, two types of target were investigated. The first type uses a spherical wall, thickness about 20 cm and radius 50 cm, composed of 90Sr, 90SrO, 137Cs, or 137Cs2O2. The target is bombarded by 14 MeV neutrons generated by inertial confinement fusion at the center of the wall. Neutronics in the wall were simulated to estimate the probability of neutron utilization per a generated neutron. The second type uses a micro target that is composed of DT fuel and 90Sr. An analytic model of the implosion of the target was formulated to evaluate the energy that is required to transmute radioactive waste (incineration energy). In the system that utilizes a spallation reaction, damages of structural material is a severe problem. To estimate the damage of structural material, atomic displacement, H production, He production, and energy deposition were calculated using computer codes, LAHET and HTAPE. (author) figs., tabs., 8 refs