Uranium Is So Last Century — Enter Thorium, the New Green Nuke

So if US utilities are unlikely to introduce a new generation of thorium reactors, it would be more practical to incorporate thorium into existing nuclear power plants. Indeed, work in this direction is beginning – thanks to a US company operating in Russia.

The hotel is located outside of Moscow, the The Kurchatov Institute is known as Los Alamos in Russia. Much of the work on the Soviet nuclear arsenal took place here. In the late 1980s, when the Soviet economy collapsed, Kurchatov scientists wore mittens to work in unheated laboratories. Then, in the mid-1990s, a savior appeared: a Virginia company called Thorium Power.

2. Light water reactor operated with uranium3. Fuel uranium fuel rods 4. Fuel input per gigawatt output 250 tons of raw uranium 5. Annual fuel costs for a 1 GW reactor 50-60 million US dollars 6. Cooling water 7. Proliferation potential medium 8. Base area 200,000-300,000 square feet, surrounded by a population zone with low density
2. Seed-and-blanket reactor3. Fuel thorium oxide and uranium oxide rods 4. Fuel input per gigawatt output 4.6 tons of raw thorium, 177 tons of raw uranium 5. Annual fuel costs for a 1 GW reactor USD 50-60 million 6. Cooling water 7. Proliferation potential None 8. Floor space 200,000 to 300,000 square meters, surrounded by a population zone with a low population density
2. Liquid fluoride thorium reactor3. Fuel thorium and uranium fluoride solution 4. Fuel input per gigawatt output 1 ton of raw thorium 5. Annual fuel costs for a 1 GW reactor USD 10,000 (estimated) 6. Self-regulating coolant 7. Proliferation potential None 8. Floor area 2,000-3,000 square meters without buffer zone Founded by another Alvin-American nuclear physicist, Alvin Radkowsky, Thorium Power has been trying to commercialize technologies that replace uranium with thorium in conventional reactors since it was renamed Lightbridge. From 1950 to 1972, Radkowsky headed the team that designed reactors for propulsion of naval ships and submarines, and in 1977 Westinghouse opened a reactor he built – with a uranium-thorium core. The reactor ran efficiently for five years before the experiment ended. Radkowsky started his company in 1992 with millions of dollars from the Prevention of Proliferation Program, which is essentially a federal effort, to keep the cool ex-Soviet weapons scientists from joining another team.

The reactor design created by Lightbridge is called a seed-and-blanket. Its core consists of a seed of enriched uranium rods surrounded by a blanket of rods made of thorium oxide mixed with uranium oxide. This gives a safer and longer lasting response than uranium rods alone. It also produces less waste, and the small piece it leaves behind is unsuitable for use in weapons.

CEO Seth Grae thinks it is better to convert existing reactors than to build new ones. “We’re just trying to replace leaded fuel with unleaded fuel,” he says. “You don’t have to replace engines or build new gas stations.” Grae is speaking from Abu Dhabi, where he has signed multi-million dollar contracts to advise the United Arab Emirates on its nuclear power plans. In August 2009, Lightbridge signed a contract with the French company Areva, the world’s largest nuclear power company, to investigate alternative nuclear fuel assemblies.

Up until the advisory side of its business was developed, Lightbridge was striving to build a compelling business model. Now, Grae says, the company has enough revenue to commercialize its seed and cover system. It has to be approved by the US Nuclear Regulatory Commission – which could be tricky since the design was originally developed and tested in Russian reactors. Then there is the not trivial question of how to win over American nuclear utilities. Seed-and-blanket not only has to work, it also has to bring a significant economic advantage.

For Sorensen, putting thorium into a conventional reactor is half a thing like putting biofuel into a lobster. However, he admits that seed and blanket design has the potential to move the country on to a greener and safer nuclear future. “The real enemy is coal,” he says. “I want to fight it with LFTRs – which are like machine guns – instead of light water reactors which are like bayonets. But if the enemy is buried in the trench, attach bayonets and go to work.” The thorium battalion is small, but – as nuclear physics shows – tiny forces can produce powerful effects.

Richard Martin ([email protected]), editor of VON, wrote about the Large Hadron Collider in issue 12.04.

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