Swiss nuclear power companies are required to find waste disposal sites within the country, but local opposition is hampering efforts to find suitable places.
The most recent site earmarked for long-term storage of Switzerland's nuclear waste is under a farming region north of Zurich, but those living nearby are far from convinced.
Residents in central Switzerland have already voted down an attempt to store waste under a hill in their canton of Nidwalden. This time it is a winegrowing community called Benken in canton Zurich, which is squaring up to block the waste experts.
New laws passed last year mean Swiss nuclear plants can no longer send their radioactive waste to France and Britain for reprocessing and leave it there.
Waste is now stored temporarily at power plants or interim storage sites pending the creation of a final repository that meets all legislative requirements. Experts estimate that it could be 2030 before construction on a permanent site gets underway.
The Benken site was identified by Nagra, the organisation charged with the disposal of radioactive waste, because it has a highly impermeable layer of clay far beneath the surface, not found elsewhere.
A 2002 feasibility study by Nagra found that the clay layer was suitable for secure nuclear disposal, and its findings have been supported by the Federal Nuclear Safety Inspectorate (HSK).
But activists in Benken are far from convinced. Jean-Jacques Fasnacht, spokesman for the group "Klar! Schweiz" says canton Zurich last year made clear it was opposed to a long-term disposal site there. "This development supports our view that all the risks have not been addressed properly," he told swissinfo.
Nagra's study focused on both low- and mid-level radioactive waste as well as high-level waste and spent fuel rods. The cabinet must now decide whether Nagra has proven that the site is indeed suitable.
But even if the federal government is convinced, there are no guarantees that a nuclear disposal site will be built. In 1988, the government approved a similar feasibility study on the site in Nidwalden only to have voters throw out the plan in a referendum in 2002.
Nagra has repeatedly maintained that its feasibility study does not mean that a final repository will indeed be located in Benken – it simply had to prove its case at a suitable site.
However, at the same time, it has financed a study on the likely social and economic fallout for the region. The study, published last September, concluded that there would be clear economic benefits for the area, but also negative effects for the image of the region, which could damage the local economy.
"Demonstrable losses would have to be reclaimed from a company operating a disposal site such as Nagra," explained Michael Aebersold, project manager at the Federal Energy Office.
"We were not in favour of such a study, but representatives of local communities commissioned it, and Nagra financed it," he told swissinfo.
The energy office has invited local communities, commercial interests and citizen's groups to make their views known. "We have just recently invited cantonal authorities to comment on our proposed procedure, so we have quite a way to go yet," said Aebersold. "It is our goal to take all comments seriously and provide a transparent basis for their evaluation."
Beyond the political debate about the proposed site, concerns remain about safety, particularly with respect to the storage materials.
The Federal Nuclear Safety Commission (NSC), which advises the cabinet, noted recently that the steel canisters envisaged for the disposal of spent fuel could eventually react with moisture and generate hydrogen gas. This would have to be released through the surrounding barriers and geology.
Although Nagra says this issue has been addressed in its recent study, the NSC says further research is still necessary, and has come up with a lengthy list of recommendations.
"We take this advice seriously," Piet Zuidema, head of Technology and Science at Nagra, told swissinfo. "We have implemented a programme to continue to study alternative canister materials such as copper. The safety and security of a repository and a site is our prime responsibility."
When the cabinet finally rules on whether Nagra has met its obligations, it will also decide which of recommendations are to be implemented. Nagra will also be asked to provide two possible repository sites, although experts agree Benken will be the most likely choice.
Once a decision is taken, the only recourse open to opponents would be a national referendum.
swissinfo, Mike Chudacoff
Switzerland currently has five nuclear power reactors, which account for most of the nuclear waste produced.
The plants will have produced around 8,000 cubic metres of spent fuel after their 50-year operating period.
This high-level radioactive waste is stored in ponds at the power plants for cooling for five to ten years. It is then packaged into transport and storage containers ("Castors") and brought to a centralised interim storage facility.
Most nuclear waste is classified as low- and intermediate-level. Nagra expects 90,000 cubic meters after an assumed 50-year period.
About 40% of Switzerland electricity comes from nuclear energy; the remainder mostly from hydroelectric plants.
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