By Michael Fröhlingsdorf, Udo Ludwig and Alfred Weinzierl, Der Spiegel, Feb. 21, 2013
Some 126,000 barrels of nuclear waste have been dumped in the Asse II salt mine over the last 50 years. German politicians are pushing for a law promising their removal. But the safety, technical and financial hurdles are enormous, and experts warn that removal is more dangerous than leaving them put.
It’s hot and sticky 750 meters (2,500 feet) underground, and the air smells salty. Five men are standing in front of an oversized drill. They have donned orange overalls and are wearing bulky special shoes, yellow hard hats and safety glasses. They turn on the machine, and the rod assembly slowly eats its way into a gray wall.
For over seven months now, the team has been trying to drill a hole with a diameter of eight centimeters (three inches). They are attempting to reach one of the former excavation chambers of Asse II, an old salt and potash mine near the northern German town of Remlingen, in the northwestern German state of Lower Saxony. Behind a barrier 20 meters thick, thousands of drums filled with nuclear waste have been rotting away for over three decades.
It’s dangerous work. Over the years, experts warn, explosive gases may have collected in underground cavities—and one spark could trigger a disaster. Consequently, the drill head is only allowed to turn extremely slowly. After the machine has barely advanced another 10 centimeters, the men pull the drill pipe out of the hole and insert a probe. They thus manage to inch their way forward about 20 centimeters per shift.
The drilling ultimately aims to provide a glimpse of the first of 13 chambers filled with barrels of waste, and to provide information on the condition of these containers—and on what measures need to be taken to remove them from the 100-year-old maze of tunnels.
It took two years to prepare this journey into the contaminated salt. Engineers had to redevelop measuring devices, design new machines and write computer programs. The men on the drilling team have volunteered for the job. They are working in a hermetically sealed space. To prevent any radioactive dust particles from reaching the rest of the mine, a constant vacuum is maintained here. There is special vinyl flooring that can be decontaminated, and the walls are lined with custom-made tiles.
German Environment Minister Peter Altmaier was on hand for the launch of the exploratory drilling on June 1, 2012. Since none of the available garb would fit him, two seamstresses had quickly sewn a white miner’s outfit for the stout politician from Chancellor Angela Merkel’s center-right Christian Democratic Union (CDU). Then Altmaier pressed a red button in a neighboring tunnel to symbolically start the drill.
At that moment, Germany cast itself into one of the most technically ambitious, and thus most costly, ventures of its industrial history—a bold, perhaps foolhardy, project that will consume at least €4 billion ($5.3 billion), but more likely somewhere between €5 billion and €10 billion. It’s a decontamination project that will take 30 years, or longer. And no one can say with certainty whether it will ever be completed.
The initial stage has already revealed that the intended retrieval of the drums is an expedition into the unknown. The team has driven the drill pipe 35 meters into the salt, yet after a good seven months of work, they still haven’t found the chamber with the stored radioactive waste. Geologists now believe that it has been missed by roughly 2.5 meters because the mountain has a life of its own and changes shape as the salt shifts from south to north.
That’s the basic situation at Asse: On the one hand, there are the engineers who want to plan everything, who have to plan everything, who are not allowed to endanger anyone, who have to adhere to the rules of the Atomic Energy Act, who have to implement the government’s plans and who should take into consideration the concerns of local residents. And, on the other hand, there are the forces of nature at work in a mine that does whatever it wants.
The decision to retrieve the drums was primarily motivated by politics. It was taken because politicians have a bad conscience about how they have treated their constituents. The public was originally informed that Asse was merely being used to “research” how radioactive waste reacts in a final repository. But then nuclear power plants, nuclear research facilities, the German military, medical institutions and industry used the old mine as a dump for all manner of contaminated waste. The federal government collected disposal fees, and for decades ministers in Bonn, Berlin and the nearby city of Hanover, the state capital, blithely disregarded the problem.
The public finally rebelled against this ignorance in 2007, when the former operator of the storage site, the Munich-based German Research Center for Environmental Health (HMGU), decided to flood the tunnels with a magnesium chloride solution. Local residents were afraid that filling the cavities could allow radioactive substances to seep into the drinking water supply. The concern was that contaminated water could reach the Elbe River and spread as far as Hamburg. Citizens’ initiatives were formed, internal papers were leaked, an investigative committee pored through thousands of binders—and it all resulted in the biggest environmental scandal in postwar German history. Now, all political parties firmly believe that the only acceptable message to local residents is the promise to retrieve the drums of radioactive waste.
When it was decided to retrieve the 126,000 drums, the BfS made a video that demonstrated how easy the job would be: It showed how robots would collect the barrels, compress them or wrap them in foil, and then bring them up to the surface. The video claimed that the operation would be completed by 2025, at the latest.
Now, it’s clear that it won’t be possible to retrieve even a single drum during the current decade. The salvage operation will mainly require the construction of an additional system of tunnels—basically a new mine next to the old one.
The new mineshaft won’t be operational before 2025. To make matters worse, there are still no plans for a packing facility or for an immense hangar in which up to 50,000 cubic meters (1.8 million cubic feet) of radioactive waste—and just as much contaminated salt—could be stored following retrieval.