Consequence analysis of fluvial erosion scenarios for a HLW repository

Miyahara, Kaname  ; Kawamura, Makoto*; McKinley, I. G.*; Inagaki, Manabu*; Ebina, Takanori*

In Japan, uplift/erosion scenarios must be analysed even if they occur far in the future, as no assessment cut-off times have yet been defined. For this purpose, the geological record of river terrace formation and their long term evolution has been studied further, with the aim of constructing a more realistic fluvial erosion model compared with the original, rather simple cyclic fluvial erosion model developed in a previous study. The model allows the consequences of erosion of the repository to be assessed, as before using comparisons with natural radionuclide fluxes. This paper describes a conceptual model based on a generalization of field observations in relevant settings and discusses resultant analyses, which again illustrate the effectiveness and robustness of the reference HLW disposal system.