The Salt Solution to Cleaner Power Generation

By Kevin Ritchart

Coal, oil and natural gas are used to produce more than 80 percent of the world’s energy, but these methods of generating power have long been proven harmful to the environment. They produce greenhouse gases like carbon monoxide as they burn, which dirties the air.

In the past several years, efforts have been made to convert to cleaner, more environmentally friendly methods of power generation through the use of the sun, wind and water. While these methods of supplying power are better for the environment, setting up large-scale solar-, wind-, or waterbased power plants is a costly and time-consuming process.

That’s why nuclear engineers like Leslie Dewan, from a Massachusetts-based company called Transatomic Power, are searching for alternate modes of power generation that are cleaner than nuclear energy, but also cheaper to produce than solar or wind power. Dewan’s company is attempting to revive a power-generating technique using molten salt that was first attempted in the 1960s.

Eating Nuclear Waste

Along with serving a cleaner-burning alternative, the molten salt reactor can effectively “eat” nuclear waste. A light water nuclear reactor uses uranium pellets that are coated with metal in its power generation process.

Over time, radiation and the collision of atoms erodes the metal coating, slowing down the fission process and necessitating the disposal of the damaged pellets. Nuclear plants store these pellets, which still contain a great deal of nuclear energy, in large containers and submerge them in water. A molten salt power plant would be able to contain and reuse the uranium rather than having to discard it.

Instead of using uranium pellets like a traditional nuclear reactor, a molten salt reactor dissolves the uranium in liquid salt, which consists of a lithium fluoride compound that’s been heated to 600°C. The utilization of liquid fuel is safer in the event of a reactor failure, as the fuel can be drained into an underground tank instead of being released into the atmosphere — as happened in the nuclear disasters at Three-Mile Island (1979), Chernobyl (1986) and Fukushima (2011).

In the 1960s, the molten salt reactor was considered too costly to produce, but Dewan’s team has come up with a smaller, more cost-efficient model that could change the way power is generated in the years to come. At this point, Transatomic Power has only run computer simulations of the molten salt reactor, but the company is planning to start building a prototype by 2020. Other U.S. companies, as well as firms in China and Japan, also are working on perfecting this technology.