Sealing radioactive waste at an underground disposal site in Asse, Germany, by flooding is the cheapest of several waste management options but would produce dangerous amounts of radioactive methane in
groundwater within 150-750 years, according to a forthcoming report from the German radiation protection agency (BfS). The findings are significant because the site, an ex-salt mine containing nuclear research waste, is geologically similar to the planned long-term disposal site at Gorleben. The report could influence calculations of nuclear waste disposal costs.
See BfS and news article