- Thorium is a mildly radioactive element, three times as abundant as uranium. There is enough energy in 5000 tons of thorium to meet world energy demand for a year. The thorium fuel cycle produces almost no plutonium and a much smaller quantity of toxic fission products than the uranium cycle.
- Reserves of thorium are widely dispersed around the world with large deposits in Australia, the USA, Turkey and India. China also has substantial thorium reserves, especially within its rare earth mineral deposits in Inner Mongolia. In Europe, Norway has 132,000 tons of proven reserves, 5% of the world’s total.
- Thorium is not fissile and therefore cannot sustain a nuclear chain reaction on its own. However, it is fertile, which means that if it isbombarded by neutrons from a separate fissile driver material (Uranium-233, Uranium-235 or Plutonium-239), or from a particle accelerator, it will transmute into the fissile element Uranium-233 (U-233) which is an excellent nuclear fuel.
- The thorium fuel cycle has been successfully demonstrated in over 20 reactors worldwide, including the UK’s ‘Dragon’ High Temperature Gas Reactor which operated from 1966 to 1973.
Thorium-Fuelled Nuclear Reactors – International Research and Development Programmes
- Research and development of thorium-fuelled nuclear reactors is underway in China, India, Norway, France, Russia, and the Czech Republic.
- The Chinese government launched a $350 million thorium-fuelled molten salt reactor R&D programme in 2011. A 2MW test reactor is due to be completed by around 2020, with a 100MW demonstration reactor to follow in the 2030s.
- The Indian government is engaged in a four stage plan for the deployment of thorium-fuelled reactors. Plutonium produced from India’s existing fleet of Pressurized Heavy Water Reactors (PHWRS) will be used in new Fast Breeder Reactors (FBRs) as a fissile driver to transmute thorium into Uranium-233. The U233, mixed with plutonium and thorium will then fuel a new fleet of Advanced Heavy Water Reactors (AHWR). The first prototype AHWR is due for completion by 2017, with four prototype FBRs due by 2020.
- Norwegian company Thor Energy is developing solid thorium fuel for use in Light Water Reactors. They have initiated a 5-year test program on solid thorium-plutonium oxide fuel taking place at the OECD Halden Test Reactor in Norway. The test program aims to demonstrate the safe, long-term performance of solid thorium fuel, and to achieve commercial readiness by 2020. The UK’s National Nuclear Laboratory (NNL) has played a key role in fabrication of the thorium fuel rods for the test program.