J-STAGE Home  >  Publications - Top  > Bibliographic Information

Journal of Nuclear Fuel Cycle and Environment
Vol. 4 (1997-1998) No. 2 p. 3-20



Research Article

  An analysis of underground autocatalytic criticality has been performed for vitrified high-level radioactive wastes arising from reprocessing of spent nuclear fuel that are placed in a water-saturated fractured geologic formation. We estimate by mass transport analyses the mass and 235U-enrichment of accumulated uranium in the host rock originated from multiple failed waste canisters, for which static neutronic analyses are performed. Uranium accumulation with 12% enrichment (denoted as U(12)) can be created. With 30% porosity of the host rock, the minimum critical mass of U(12) required for over-moderated criticality is 280 kg. Heterogeneous U(12) depositions can exhibit positive reactivity feedback due to medium temperature increase.

Copyright © 1998 Division of Nuclear Fuel Cycle and Environment, Atomic Energy Society of Japan

Article Tools

Share this Article