Nuclear physicists in Berlin claim to be able to drop the life span of nuclear waste from 100,000 years to 300. But, does that make it green? And should it raise the chances of a nuclear power rethink in Germany?
The dual fluid reactor is nothing more than a proposal, at the moment. But it's one that attempts to address the thorniest problem associated with nuclear power production.
Radioactive waste from nuclear power plants is typically stored underground. In Germany, it is famously lowered into abandoned salt mines, where the bright yellow barrels expel radiation for upwards of 100,000 years.
A dual fluid reactor, says the team of researchers developing it, would drop that number to between 300 and 600 years.
The key is swapping nuclear fuel rods for salt mixtures. Liquid salts with heavy nuclei - plutonium chloride or uranium chloride are the examples used by the nuclear physicists in the project - would flow in continuous circles. After burning in the reactor core and producing energy, the liquid is then channelled through an internal treatment plant, where burned components are separated off and the mixture is enriched once more with fresh, long-life radionuclides. It's then sent back through the reactor core for another round of energy production.
Those burned components are radioactive. They, too, would need to be stored in a safe location. After 300 to 600 years, though, they would be recycled as valuable metals, with any unused nuclides heading back to the reactor.
Though nuclear waste produced by a dual fluid reactor would have a far shorter lifespan, those materials would radiate far more intensely during that period.
"It's like a battery," said Götz Ruprecht, one of the nuclear physicists involved in the project. "Either you use very little power over a longer period, or you use a lot of power over a shorter period."
The scientist added that current and future nuclear waste storage facilities in Germany, which include a planned 30-billion-euro facility in the coming decades, are capable of handling the highly radioactive end product.
Still, for the organizers of the recent GreenTec Awards, held in Berlin, the dual fluid reactor submission was an awkward guest. It was nominated for the award via a public Internet vote. GreenTec organizers tried to get the project struck off the list, a decision which was over turned by Berlin's courts. They argued the project didn't meet the stated goal of new advances in green technology that raise "ecological and economic consciousness and commitment."
Radioactive waste cools from 400 to 200 degrees celsius in a storage facility before being buried underground
Not usually 'Made in Germany'
In Germany, nuclear reactors are not generally viewed as 'green' alternatives to coal power production. The anti-nuclear movement is strong, with protestors frequently stopping transportations of nuclear waste. Popular yellow stickers resembling smiley faces instead read, "Atomic power? No thanks!"
In the weeks following the Fukishima nuclear disaster in March 2011, Chancellor Angela Merkel's ruling coalition announced Germany would close its nuclear reactors by 2022.
Ruprecht isn't dissuaded, though, citing popular frustrations at rising energy costs as a potential turning point in the nuclear energy debate.
"At some point everything will become expensive enough that people will think things over again," he told DW. "That point could come faster than you'd think."
Even if his team's technology is never employed in Germany, his institution, the privately- and publicly-funded Institute for Solid-State Nuclear Physics in Berlin, is in talks with other institutions throughout the world about developing the technology. Canadian institutes with ties to energy companies in Canada have shown particular interest in the technology.
"We're trying to find investors and that's naturally a bit difficult since we're talking about billions of euros," he said.
Still, Ruprecht estimates that working prototypes will be available in around ten years.