Thorium nuclear reactor technology does not impress

NuClear News No.61 April 2014  There’s a modern mythology that suggests that thorium might be able to replace uranium and deliver a safer and cheaper nuclear reactor with more abundant fuel. In March press reports suggested that Chinese scientists have been told to accelerate plans to build the first fully-functioning thorium reactor within ten years, instead of 25 years as originally planned. The Telegraph said they “may do the world a big favour. They may even help to close the era of fossil fuel hegemony.” (1)

Jan Beránek, leader of Greenpeace International’s Energy Campaign says we’ve heard all this before. Thorium technology is in principal based on nuclear fission and therefore keeps fission’s inherent problems. While it partially addresses some of the downsides of current commercial reactors based on uranium (plutonium) fuel, such as limited reserves of uranium and unwanted production of plutonium and transuranic isotopes, it still has significant issues related to fuel mining and fabrication, reactor safety, production of dangerous waste, and the hazards of the proliferation of nuclear weapons. (2)

The Union of Concerned Scientists point out that thorium cannot be used by itself to sustain a nuclear chain reaction: it must be used together with a fissile material such as enriched uranium, uranium-233, or plutonium. The U.S. Department of Energy has concluded after a review that “the choice between uranium-based fuel and thorium-based fuel is seen basically as one of preference, with no fundamental difference in addressing the nuclear power issues [of waste management, proliferation risk, safety, security, economics, and sustainability].” (3)

UCS continues some people believe that liquid fluoride thorium reactors, which would use a high-temperature liquid fuel made of molten salt, would be significantly safer than current-generation reactors. However, such reactors have major flaws. There are serious safety issues associated with the retention of fission products in the fuel, and it is not clear these problems can be effectively resolved. Such reactors also present proliferation and nuclear terrorism risks because they involve the continuous separation, or “reprocessing,” of the fuel to remove fission products and to efficiently produce U-233, which is a nuclear weapon-usable material. Moreover, disposal of the used fuel has turned out to be a major challenge.

Even the UK Department of Energy and Climate Change commissioned a report which concluded in 2012 that the claims by thorium proponents who say that the radioactive chemical element makes it impossible to build a bomb from nuclear waste, leaves less hazardous waste than uranium reactors, and that it runs more efficiently, are “overstated“.http://www.no2nuclearpower.org.uk/nuclearnews/NuClearNewsNo61.pdf