Temperature distribution in a hypothetical spent nuclear fuel repository in a salt dome.

摘要

In this report the results of the thermal analysis of a hypothetical spent nuclear fuel repository in The Netherlands are presented. The repository is supposed to be located in a salt dome, the disposal techniques used is a mine concept with vertical boreholes and the waste is spent fuel from Borssele (450 MWe) and Dodewaard (50 MWe) plants plus three more reactors, 1000 MWe power each. The different heat power of every canister due to the different interim storage time of every fuel assembly was accounted for in the model. The analysis was made with the TASTE programme which implements the analytical solution of the heat conduction equation for a continuous time-dependent point source. Vertical temperature rise distributions as well as horizontal distributions were calculated for the hottest points of the repository. The maximum temperature rise found in the analysis was 145.6 degree celsius, accounting for the geothermal gradient. This maximum occurs 35 years after closure, on the surface of a borehole placed in the centre of the repository, at a depth of some metres above the middle horizontal plane of the repository. These temperatures do not seem to be high enough to cause severe changes on properties of the surrounding salt, and however they may contribute to accelerate the convergence process of salt, but the quantification of these processes would need a deeper secondary analysis. (8 ref., Il. color)