Thorium Reactor

Schematic from Wikipedia

We had earlier covered how nuclear technology could help mitigate carbon emissions that would otherwise arise from fossil energy use. Nonetheless, the technology relies heavily on uranium as its fuel, and thus faces risks and challenges such as reactor melt-downs, nuclear waste management and potential of nuclear proliferation.

Reuters recently ran an article that suggests thorium could replace uranium as a clean, safe and sustainable energy source for the future. Thorium is four times more abundant that uranium, and the molten salt reactor (MSR, schematic above) compatible with thorium use has the advantage of allowing the whole system to operate close to normal atmospheric pressure. This is in contrast to conventional water-cooled reactors that require heavy engineering to withstand high pressure that can result in the danger of leaks and explosions. Thorium yields less waste and is less radioactive, compared to traditional uranium reactors. 

The feasibility of thorium reactors was given a boost when former UN nuclear weapons inspector Hans Blix gave his personal support to the technology as reported by the BBC. Various countries such as Canada, China, Germany, India, the Netherlands, the UK and the US are also experimenting with thorium as a substitute fuel. 

Hargraves and Moir (2010) published a paper in American Scientist that comprehensively summarised the Liquid Fluoride Thorium Reactor (LFTR) technology. Apart from suggesting that thorium is a relatively safe option, the article also suggests that the thorium reactor would be economically viable in the long run, and the risks of nuclear proliferation is minimised compared to a uranium reactor. 

Cooper et al (2011) suggests that a LFTR program could be achieved within 5-10 years with an investment of roughly $1 billion. However, a Mar 2012 report by the UK National Nuclear Laboratory (NNL) suggests that present market conditions may not favour development of the LFTR, and it may take up to 20-30 years before the LFTR technology may become economically viable. 

The LFTR developments signal an exciting new generation of nuclear energy technology that is much safer and more sustainable to operate as compared to the existing uranium based technologies. If successful, the future may see more thorium based nuclear reactors that could help mitigate the impacts of climate change.