Some Considerations on ^242mAm Production in Thermal Reactors

Recently, it has been suggested to consider ^242mAm as a potential nuclear fuel. This artificial nuclide can be produced through ²⁴¹Am neutron capture carried on in a neutron field typical of a thermal reactor. In order to suppress the thermal neutron flux, which will cause ^242mAm depletion mainly through fission, proper neutron filters should be adopted. In a very intense neutron field, the ^242mAm enrichment depends mainly on the energy distribution of the neutrons, the sample thickness, and the cutoff energy of the neutron filter.

An investigation on different geometries of the sample to be irradiated using Cd, B, Sm, and Gd as neutron filters has been carried out by means of Monte Carlo simulation. The most favorable results have been obtained irradiating thin ²⁴¹Am samples (11 g/cm²) covered with a Gd (0.2-mm-thick) or Sm (1-mm-thick) filter. In these cases the theoretical ^242mAm enrichment can reach 20%.

The preparation of significant quantities of this unconventional nuclear fuel implies isotopic separation techniques operating in high radioactive environments and hopefully characterized by very high recovery factors, which are in no way trivial problems.