As news breaks that Japan’s nuclear agency has upgraded the severity level of a radioactive water leak at the Fukushima plant from one to three, another story tells of a safer alternative to uranium. It’s name? Thorium. Occurring in the earth’s crust more commonly than tin, mercury and silver, and three times as much as uranium, the element is currently being tested in Norway by Thor Energy. The UK’s National Nuclear Laboratory, Germany and the US are also involved.
Thor Energy’s chief executive Øystein Asphjell told The Daily Telegraph that “Thorium addresses a lot of the accident fallout from uranium because it has a much higher melting point, it cannot be dissolved in water, and there’s multiple safety parameters that are inherent in the material properties”. He added, “The thermal conductivity of thorium-based pellets is known to be much better than uranium.” Last April, the company fed thorium rods into a test reactor as part of a five year radiation programme designed to definitively demonstrate the benefits of the element.
Some experts claim that thorium works even better in molten salt reactors, allowing fission products to be re-added to the reactor thus making energy generation cheaper. It has even been mooted that this type of reactor could have prevented the hydrogen explosions experienced in Japan because if power is lost, a plug in the base of the reactor melts and the salts flow into a containment vessel to cool down, halting the reaction and any release of radiation.
Along with Norway, China is at the forefront of research. In 2011, it launched a $350m R&D programme into the concept of thorium-fuelled molten salt reactors, with the hope of building commercially viable plants in the 2030s. India hopes to have four new fast breeder reactors up and running by 2020 and is home to 16 per cent of the world’s thorium.