The delay has had knock-on effects. In 2014, barrels of nuclear waste destined for Konrad that were in temporary storage at a decommissioned power plant were found to be corroded. They are being kept in concrete-walled pits not intended for long-term storage. Costs are also mounting. It is estimated that Germany’s Office for Radiation Protection – a government agency – is spending more than 3.4 bilion euros (£2.9bn) converting Konrad into a repository and moving waste into it, and more delays would only increase that sum.

Konrad was picked partly because it is an unusually dry mine, thanks to a 400m (1300ft) thick layer of clay that seals off the mine from groundwater. One of the greatest fears about storing radioactive waste underground is that seeping water could gradually erode containment vessels and carry radioactive material up to the surface. Even if the process took thousands of years it could still be disastrous.

“There is some moisture here,” admits Schneider as he points out a row of bright white stalactites. But they are largely made of salt and he says saline solutions are less mobile than fresh water underground. Those involved in the project believe it would take at least 300,000 years for this moisture to rise to the surface. By then, the waste’s radioactivity should be harmless.

Show of opposition



The village of Bleckenstedt lies a two-minute drive away from Konrad’s main entrance. Bright yellow oil drums, painted to look like canisters of radioactive material, sit at the side of the road and in people’s gardens. It’s just one way that a handful of the village’s roughly 600 residents have chosen to show their opposition to the neighbouring mine’s transformation into a nuclear waste dump. There are also signs from anti-nuclear marches on display and an elaborate mural painted on a barn door that warns about the dangers of radiation.

One resident is unhappy because he bought an apartment a decade ago, before Konrad was granted the licence for nuclear waste storage. He claims the value of his property has since fallen to a third of what it was. He believes the German government should compensate locals for the effect on property value. Another local tells me she is worried about something going wrong in the mine. “We see what happened in Asse,” she says.