Repository criticality analysis for damaged fuels; Geometry effect in the modeling of uranium and plutonium deposition in geological formations

Liu, X.*; Ahn, J.*; Hirano, Fumio

Proceedings of 14th International High-Level Radioactive Waste Management Conference (IHLRWMC 2013) (CD-ROM), p.527 - 534, 2013/04

The present study focuses on the criticality safety of geological disposal of molten fuel. The influences of different geometries in the MCNP models for the simulation of heavy metal precipitates in geological formations are discussed. Bounding calculations for criticality based on the molten fuel in Fukushima Daiichi reactors were made by optimization in a large parameter space. Some critical combinations are observed in the numerical results, and in the iron rich rock, the risk of criticality is significantly reduced.