Underground cooling enhancement for nuclear waste repository

This patent describes a long-term repository system for the storage of heat generating spent nuclear fuel. It comprises a mechanically stable geological formation constituting a natural barrier system for the spent fuel; a drift tunnel defined in the geological formation, the drift tunnel having a height and a width, and a length much greater than the height and the width; container receiving boreholes defined in the stable geological formation and in communication with the drift tunnel; containers of spent, heat generating nuclear fuel, the containers being positioned in the container receiving boreholes; elongated heat transfer boreholes having a length and having an average cross-sectional width much smaller than the length and extending to a heat dissipation region in the geological formation, which region is remote from the drift tunnel; and a heat transfer device extending from a portion of the geological formation adjacent one of the container-receiving boreholes to receive heat from the spent fuel and extending into and through each the elongated heat transfer borehole to the remote heat dissipation region