Nuclear Waste Management Organization of Japan (NUMO) has proceeded with repository siting, since 2002, based on an “open solicitation procedure”. While waiting for volunteer municipalities and having no specific site geological information, NUMO has been preparing for expected assessments and designs at the investigation stage. One of the efforts for preparation is the dry run using hypothetic...

We study the homogenization of two models of an underground nuclear waste repository. The nuclear waste cells are periodically stored in the middle of a geological layer and are the only source terms in a parabolic evolution problem. The diffusion constants have a very large contrast between the fuel repository and the soil. It is thus a combined problem of homogenization and singular perturbat...

The Mizunami Underground Research Laboratory (“MIU”) is now under construction by Japan Atomic Energy Agency (JAEA) in the Cretaceous Toki granite in the Tono area of central Japan. One of the main goals of the MIU project, which is a broad scientific study of the deep geological environment as a basis of research and development for geological disposal of nuclear wastes, is to establish compre...

■ Abstract We review selected geological processes to which numerical modeling has been applied, with the aim of describing some of the general approaches and applications of the modeling. All of these examples involve multiphase fluid flow, in some cases coupled with heat transport and phase changes. First, we describe modeling approaches to a human-made geological system—a potential undergrou...

Abstract. When stresses yield a critical value, rock breaks or pre-existing faults are reactivated, generating pathways for fluid migration. Thus, the contemporary undisturbed stress state is key parameter assessing stability of deep geological repositories and quantifying whether changes induced by sub-surface constructions storage heat-generating waste lead to state. The prediction 3D achieve...

Scenarios of barrier failure and radionuclide release to the near-surface environment are important to consider within performance and safety assessments of repositories for nuclear waste. A geological repository for spent nuclear fuel is planned at Forsmark, Sweden. Conceptual and numerical reactive transport models were developed in order to assess the retention capacity of the Quaternary til...

For a deep geological repository for spent nuclear fuel planned in Sweden, the safety assessment covers up to 1 million years. Climate scenarios range from high-end global warming for the coming 100 000 years, through deep permafrost, to large ice sheets during glacial conditions. In contrast, in an existing repository for short-lived waste the activity decays to low levels within a few tens of...