Cyclic mode of neptunium, americium and curium transmutation in heavy-water reactor

Characteristics of process of transmutation of neptunium, americium, and curium from spent nuclear fuel in heavy-water reactor during first 10 lifetimes and at transition to equilibrium mode are calculated. During transmutation, dangerous nuclides, first of all, 244Cm and 238Pu are accumulated. They cause an increase of radiotoxicity. At first 10 cycles of transmutation, the radiotoxicity is increased by 8.7 times in comparison with initial load of transmuted actinides. Heavy-water reactor with thermal power of 1000 MW can transmute neptunium, americium, and curium extracted from 3.7 VVER-1000 type reactors. It means that the required power of transmutation reactor makes about 8 % of thermal power of VVER-1000 type reactors. (author)