But German nuclear consultant Gerhard Schmidt says that this is a method from the 1980s, and would never be considered in Germany today. He says that a mine shaft at least 800 metres deep is necessary, to contain the waste for tens of thousands of years.
After the chamber near Forsmark is sealed, it will fill with water, meaning a slow leackage of waste. This will not release an unsafe level of radiation, says the director of SKB, Saida Laârouchi Engström.
The Swedish waste company's application to build the underground waste chamber is being considered by the Radiation Safety Agency.