Some 800m below the town of Gorleben, northern Germany, salt glistens like ice underfoot.
The man in charge of the nation’s nuclear waste is walking through caverns carved into a huge salt formation that could one day entomb 17,000 tonnes of highly radioactive detritus.
Walk carefully, salt is slippery,” says Wolfram Konig, head of the federal office for radiation protection. It is the liquid quality of salt that brings him here. Over a period of years it “flows”, he says, filling holes in its structure and enveloping objects placed within it – a geological seal that is ideal, some say, for burying Germany’s high-level nuclear waste.
A quarter century of drilling and €1.5bn ($2.1bn) in expenditure have created 11km of tunnels. About 170 men are blasting 40m of new tunnel every week. Scientists have found nothing to suggest that the “research mine” is not up to the task, Mr Konig says. There is no sign of groundwater that would corrode nuclear storage bins or of any rock seams that could disrupt the integrity of the ancient salt strata.
And yet, despite this Germanic thoroughness, Gorleben remains the focus of a bitter standoff about using this rural site to bury nuclear waste for hundreds or thousands of years.
So undemocratic was the 1977 decision by the state of Lower Saxony to designate Gorleben for nuclear disposal that it remains an affront to many locals, as well as to national politicians.
Although there is no nuclear material on the site, it is cut off from the surrounding forest by barbed wire and police – not things that inspire the open dialogue the issue demands, Mr Konig admits.
But Germany’s new-found political consensus to phase out nuclear power by 2022 offers a “small window of opportunity”, he thinks, to finally decide whether the country’s most dangerous nuclear waste should be buried in Gorleben or somewhere else.
Divisions over nuclear power stymied a first attempt nine years ago. An anti-nuclear government of Social Democrats and Greens suspended exploration at Gorleben as a prelude to a new search for a storage site, only to see this initiative blocked by pro-nuclear Christian Democrat state governments in Baden-Württemberg and Bavaria.
But Japan’s nuclear disaster in March saw chancellor Angela Merkel push her Christian Democrats into a dramatic change of heart.
Having postponed the country’s nuclear phase-out from 2022 to 2036 last year and restarted work at Gorleben, the party this spring swung back to the earlier deadline. Opposition Social Democrats and Greens demanded a new search for a waste repository as the price for parliamentary backing.
Ms Merkel and environment minister Norbert Röttgen have signalled agreement, no doubt encouraged by Bavaria’s recognition that opposition to a new search is no longer timely, and by Baden-Württemberg’s new state government of Greens and Social Democrats.
The government’s geological survey found northern Germany has three other salt formations and a band of claystone fields that are also worth examining. It also sees a big clay formation that straddles Bavaria and Baden-Württemberg as a possibility – although neither state has shown much enthusiasm.
With Social Democrats and Greens also pushing for the exclusion of Gorleben from a new search, Mr Konig warns of repeating “the mistakes of the past”. Ruling out certain areas on political grounds would sully a new search with the same backroom politicking which the initial selection of Gorleben was never able to shake off, he says. Only an open inquiry could hope to render the necessary public acceptance of a final site.
Despite cross-party unity on phasing out nuclear power, Germany’s politicians still have to prove that they can come together on the related problem of nuclear waste storage. The European Union wants governments to present plans by 2015, and Mr Konig reckons a German repository could be up and running by about 2040.
“If we go about this the right way, we’ll find a new site,” he says. “Or we’ll finally prove Gorleben was the best option all along.”