After 18 months of negotiations, an agreement has been signed today between the ITER parties to build the experimental fusion reactor in Cadarache, France.

The 10 billion project will be the most expensive joint scientific collaboration since the International Space Station.

Nuclear fusion extracts energy from same reaction that powers our sun. It is much cleaner than nuclear fission and fossil fuels, producing very little radioactive waste with no risk of meltdown.

Temperatures of over 100 million degrees celcius (many times the temperature of the centre of the sun) are required to sustain a fusion reaction capable of producing large amounts of energy. The ITER (International Thermonuclear Experimental Reactor) will be the first fusion reactor to produce thermal energy comparable to the levels of conventional power stations.

Relevant stories

France gets nuclear fusion plant (BBC)

France wins fusion project (Nature.com)

Europe beats Japan to ITER prize (physicsweb)