With an ID of around 10-in (260-mm), I get the sense they would need multiple boreholes to dispose of any significant quantity of waste.The waste would be sealed within two stainless steel canisters, and placed within a permanent steel casing that is grouted into place. The bottom of the hole would be plugged first, and the top would have some kind of backfill. I imagine the key to this technology is the geologic media the waste is being stored in. Obviously a site with a deep groundwater table would be significant. Any thoughts on what else one would be looking for in terms of the site and specifically the geology? Do you think the U.S. would ever implement such a system?
Check out the original post at Radwaste, or visit the BOSS site at the IAEA for more info.