PLUTONIUM BURNUP TYPE FAST REACTOR

摘要

PROBLEM TO BE SOLVED: To improve a burnup reactivity loss and a Doppler coefficient which are important from the economic and safety viewpoints without reducing greatly a plutonium burnup ratio. SOLUTION: This fast reactor has a core in such a form that a fuel produced by using an inert base material other than uranium as the base material and by mixing plutonium oxide with the inert base material is loaded, and has a structure having a two-region core having an inside core 10 with a low enrichment degree of Pu(plutonium) and an outside core 12 with a high enrichment degree of Pu and enclosed by a shield without a blanket in the radius direction and without a blanket in the vertical axial direction of the core. Inner blankets including U(uranium)-238 are arranged near the centers in the axial directions of the inside core 10 and the outside core 12, and the inner blanket 14 in the axial direction of the inside core 10 is set thicker than the inner blanket 16 in the axial direction of the outside core 12. the thickness of the inner blanket 16 in the axial direction of the outside core 12 is preferably about one-third to a half of the thickness of the inner blanket 14 in the axial direction of the inside core 10.