SaintUrsanne, Switzerland,:Storing radioactive waste above ground is a risky business, but the Swiss think they have found the solution: burying spent nuclear fuel deep underground in clay.
The Mont Terri international laboratory was built to study the effects of burying radioactive waste in clay which sits 300 metres (985 feet) below the surface near Saint-Ursanne in the northwestern Jura region.
The underground laboratory stretches across 1.2 kilometres (0.7 miles) of tunnels. Niches along the way, each around five metres high, are filled with various storage simulations, containing small quantities of radioactive material monitored by thousands of sensors.
More than 170 experiments have been carried out to simulate the different phases of the process — positioning the waste, sealing off the tunnels, surveillance — and to reproduce every imaginable physical and chemical effect.
According to experts, it takes 200,000 years for the radioactivity in the most toxic waste to return to natural levels.
Geologist Christophe Nussbaum, who heads the laboratory, said researchers wanted to determine what the possible effects could be “on storage that needs to last for nearly one million years.”
That “is the duration that we need to ensure safe confinement,” he said, adding that so far, “the results are positive.”
