Roles of conceptual model development for realistically quantifying radionuclide migration

Miyahara, Kaname  ; Tachi, Yukio  ; Kitamura, Akira  ; Mitsui, Seiichiro  ; Sawada, Atsushi ; Shibata, Masahiro ; Neall, F.*; McKinley, I. G.*

As the Japanese deep geological disposal programme prepares for milestones at which volunteer sites need to be compared, it is critical that any supporting post-closure safety assessment is done as realistically as possible. Because of the subtle system understanding needed to integrate diverse theoretical, laboratory, field and analogue models, data and observations into the high-level parameters that are incorporated into performance assessment models, normal QA procedures tend to fail completely. This problem is discussed further in this paper and solutions outlined, which build on recent developments of supporting knowledge engineering tools.