Optimization of closed nuclear fuel cycle including transmutation of minor actinides

Up to now no definite internationally recognized quantitative criterion of minor actinides transmutation efficiency was worked out though it would be highly desirable. The parameters which should be taken into account in working out such criteria are discussed on the base of calculations of isotope kinetics of MA transmutation in thermal and fast neutron spectra with americium recognized as primary target. Even isotopes of plutonium are considered as 'ballast actinides' because their accumulation results in deterioration of the fuel properties of recycled actinides composition. The mass of uranium as irreparable natural raw material spent to transmute a unit mass of MA and average energy released per neutron absorbed by the fuel mixture are also taken into account. (author)