A 208Pb coolant for a multipurpose nuclear reactor

Abstract

Natural lead containing 52.3% of stable isotope 208Pb can be applied in the nuclear small power engineering as such a coolant for fast reactors of various purposes. In this case unique consumer properties of 208Pb might be realized which are the following: the low inelastic scattering and small absorption of neutrons by 208Pb nuclei.In the paper is shown that a high-enough neutron spectrum can be achieved in a small dimensions core fueled with a plutonium-zirconium alloy (Pu-Zr) and cooled with natural lead. In fulfilling these conditions, an average neutron energy in the core center is equal to 0.869 MeV and a share of hard neutrons (En>0.8 MeV) reaches the value of 35%.The replacement of the lead coolant with a 208Pb coolant leads to further increasing the average core neutron energy up to the value of 0.991 MeV and increasing the share of hard neutrons in the neutron spectrum up to 42%.An interest for creating hard neutron spectrum reactors is high-enough mainly thanks to their ability to transmutate minor actinides (Np, Am, Cm) into fission products.Production of radio isotopes for medicine and investigation of radiation damages in materials of nuclear engineering may be other applications of hard neutron spectrum reactors.