The triple meltdown in march at Japan’s Fukushima Daiichi plant cast a long shadow on nuclear power in Western countries. At least 25 reactors have been shuttered or canceled in Europe since the disaster, and public support in the United States is once again plummeting. But in China, where energy demand is skyrocketing, the appetite for nuclear power is undiminished. In January the nation announced a 20-year plan to pursue an experimental reactor design called a molten salt reactor (MSR). Instead of running on solid uranium—the industry’s mainstay for more than 50 years—it would rely on liquid fuel suffused with thorium, which is three times as abundant as uranium.
The reactor concept calls for heated salts that act as both a coolant and a medium for fission reactions. Theoretically, this configuration would prevent fuel from overheating and breaching the reactor’s containment vessel. In the event of an increased core temperature or a power failure, the hot liquid salt melts a plug at the bottom of the reactor and drains into passively cooled containment vessels, limiting the risk of radiation release into the environment. “MSRs provide more safety options than what we have today,” claims Kirk Sorensen, president of Flibe Energy, a start-up based in Huntsville, Alabama, pursuing a thorium-fueled MSR. Another potential benefit is that because the reactor uses its thorium fuel more efficiently, it could reduce radioactive waste by a factor of around 100 compared with conventional reactors, says Per Peterson, a professor of nuclear engineering at the University of California, Berkeley.
Oak Ridge National Laboratory in Tennessee successfully tested the largest-ever MSR prototype in the 1960s, but the technology has languished ever since. Stateside, money may be the biggest deterrent to further development, since construction costs for a radically new reactor could far exceed the $10 billion-plus price tag for a conventional uranium plant. China, which is already constructing 25 new reactors, may be the only nation flush enough to push the technology to the next level.
Here Kirk Sorensen gives a short (10 mins) TEDx talk about MSR technology: