Germany ended the era of nuclear energy in Europe's biggest economy when it decommissioned the last three remaining nuclear power plants on April 15 this year. Decades of nuclear power generation, however, have left a legacy that is unlikely to go away as smoothly as the phaseout: nuclear waste.

Since a permanent German storage facility is out of sight in the near future, the spent fuel rods, packed into specialized containers called Casks for Storage and Transport of Nuclear Material (CASTOR), will likely remain in interim storage for decades.

About 1,200 CASTOR containers are currently stored at 17 interim sites in Germany. A state-owned company, the Bundeseigene Gesellschaft für Zwischenlagerung mbH (BGZ), is tasked with operating the sites.

BGZ spokesperson Janine Tokarski told DW that the company finally expects "about 1,800 containers from across Germany to be designated for final disposal."

Another state company, the Federal Company for Radioactive Waste Disposal (BGE), is exploring sites in Germany for the final disposal of the dangerous waste. According to Tokarski of BGZ, experts plan to find a site and, more importantly, reach a political consensus on it "in the 2040s at the earliest."

From then on, another 20 to 30 years are likely to be spent on planning and construction, said Tokarski. She anticipates the beginning of final storage "in the 2060s at the earliest." The shipping of all the waste from the various interim sites will probably take another 30 years, she added.

The century-long operation is expected to cost hundreds of billions of euros. Last year alone, BGZ spent €271 million ($292 million) just to ensure Germany's nuclear waste is safely stored — €191 million of the sum on operating the interim sites and €80 million on investments in them.

A nuclear fortress

In 1992, the first CASTOR containers with highly radioactive fuel rods were stored in the interim storage site of Ahaus in northwestern Germany.

The 200-meter-long (218-yard-long) central storage building towers 20 meters high above the flat landscape of the Münsterland region and is protected by a wire fence surrounding the sprawling 5,700-square-meter (61,354-square-feet) site.

Bisected by a reception and maintenance area, the building currently holds more than 300 yellow casks containing burned fuel rods. Additionally, six CASTOR containers, each 6 meters long and weighing 120 tons, are stored in one of the two halls, keeping the waste leak-tight for a calculated 40 years.

Leak tightness is achieved through a pressure switch installed in the double-wall sealing system of these containers, said David Knollmann from BGZ in Ahaus.

"A gas is inserted between the two walls, specifically helium gas, at a certain pressure. This switch ensures the pressure doesn't fall below a certain level," he told DW.

David Knollmann proudly added that in 30 years, there hasn't been a single case of a container requiring repairs.

The nuclear safety at the Ahaus interim storage site is not only overseen by German nuclear authorities but also by Euratom, an independent nuclear energy organization run by European Union member states, and the International Atomic Energy Agency (IAEA). Their auditors inspect the site regularly but without advance notice.

Pressure of time

In addition to the two central interim storage facilities in Ahaus and Gorleben, Germany operates other decentralized temporary storage facilities at the sites of all former German nuclear power plants.

Moreover, additional waste, shipped for reprocessing to France and the UK, will eventually return to Germany. Knollmann said this will only happen "when all the necessary regulatory conditions are met."

Much of the waste, he explained, comes from "dismantled nuclear power plants" and includes contaminated pumps and filters. Those would eventually be stored at the Schacht Konrad site near the town of Salzgitter, a former iron ore mine proposed as a deep geological repository for medium- and low-level radioactive waste.

The Schacht Konrad mine, said Tokarski, is expected to become operational as a nuclear waste storage "around the early 2030s."

All German interim storage sites are subject to limited operating permits of 40 years. For example, the permit for the Ahaus site will be up for renewal by 2028 at the latest. As all experts agree that a final central repository for Germany's nuclear waste won't be fully operational before 2090 at the earliest, the country faces the problem of what to do with the radioactive material until then.

Without political consensus on the issue, Ahaus residents fear that their neighborhood's storage facility might secretly become "a final repository solution."

This article was originally written in German.

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