Technical Report NTB 85-54
Thermal loading in the near field of repositories for high and intermediate level nuclear waste
The feasibility, the principal features and operational aspects of the two underground nuclear waste repositories Type B and Type C have been analysed in the Nagra "Project Gewähr 1985" study.
The near-field thermal calculations performed for this study are described in detail in this report. The calculations, which have been made to ensure that there is at no time a risk of excessive temperatures being reached, account for heat transfer by conduction, convection and radiation. All these mechanisms may be relevant during the first few years after disposal.
The high-level wastes considered are reprocessing waste and spent fuel. The heat generating intermediate level wastes comprise hulls and end caps, co-precipitation sludges from reprocessing and certain decommissioning wastes. Disposal of heat-generating wastes has been analysed both for the Type B and the Type C repository. Within the present repository concepts, acceptable temperature distributions can be achieved by appropriate disposal plans and configurations.
