Use of Neptunium-containing Fuel in Lead-cooled Fast Reactor

The paper analyzes a principal capability to transmute neptunium, the main component of transuranium radiowastes (TRW), in lead-cooled fast BREST-type reactor. High-energy neutron spectrum of the BREST-type fast reactor makes it possible either to eliminate neptunium in fission reactions or convert neptunium to plutonium with large fraction of 238 Pu in radiative neutron capture reactions. According to the IAEA regulatory documents, plutonium containing above 80% 238 Pu is regarded as an unsuitable material for manufacturing of nuclear explosive devices. Besides, good neutron-multiplying properties of 238 Pu and 239 Pu can prolong substantially the reactor core lifetime. Thus, introduction of neptunium into fresh fuel composition can eliminate the largest TRW fraction, strengthen regime of nuclear non-proliferation, produce some additional amount of thermal energy and prolong the reactor core lifetime.