Possibility of Burning Americium in Fast Reactors

Abstract

The possibilities of burning americium from spent nuclear fuel of thermal reactors in the operating BN-800 are examined. It is shown that because of the small fission cross-section in the neutron spectrum of a fast reactor all of the americium cannot be directly converted into fission products. This can be done only by transmutation of americium into plutonium, which must be separated and directed into fuel, where it will burn. In a reactor only 15–20% of the americium is transmuted, and the remaining americium must be returned into the reactor for transmutation. The volume of the recycled americium can be significantly reduced by burning in facilities possessing a moderator (zirconium hydride) and the need for burning it can be eliminated by using plutonium with a high content of the isotope 241Pu as the fuel of fast reactors, where this isotope fissions efficiently.