Big brains are racing to save our power-hungry planet. While solar, gas and wind are increasingly playing a role, many say there’s no escaping the need for nuclear power to maintain our tech-heavy worlds. Lucky for us, scientists believe they’ve found a way to eliminate smog-inducing coal production and reduce the risks and costs of nuclear power.

The answer? A renaissance fueled by molten salt reactor (MSR) technology, a way of dissolving uranium pellets in molten salt and transforming them into a liquid that can be safely kept in reactors for decades. So far, Beijing has proven the biggest gambler — investing a whopping $350 million — but researchers and firms in the U.S., Canada and Europe are also running full speed ahead, and global deployment of full-scale test reactors is expected before 2030. Experts reckon this revolutionary system could be cheaper to use than coal, and, because the liquid can be drained into tanks and quickly cooled in emergencies, MSR holds the promise of a future free of Chernobyl-style meltdowns.

When we produce power cheaper than coal-fired plants, demand will be huge. –Moltex lead engineer Rory O’Sullivan

Nuclear power currently provides 11 percent of the world’s energy. But that number needs to grow to 17 percent to hit the globe’s targeted carbon dioxide emission reduction levels by 2050, according to the International Energy Agency. And the robust and reliable nature of CO2-free nuclear power complements the expansion of more intermittent renewable energy, lowering demand for fossil-fuel generation. But to safely deliver, nuclear plants can’t carry the costs, safety or political baggage of existing sites. There are six leading technologies among the so-called fourth generation of nuclear power plants — all of them offer improvements, but MSR promises the best economy, some experts say. “[MSR has] a reasonable chance of being the winner” in the race, says Stephen Tindale, director of the U.K.-based Alvin Weinberg Foundation, a nonprofit organization advocating the use of advanced nuclear technology.

The process operates at temperatures in excess of 1,200 degrees Fahrenheit and at low pressure, which means it can produce more heat and extract more power from the fuels without the risks of today’s high-pressure systems. Also, radioactive gases don’t exist with MSR, which means that any nuclear fallout is contained within the plant and doesn’t hurt the surrounding area. Reactors can also be designed to burn plutonium or thorium, the latter being a scalable material well suited for energy-intensive industries such as cement and desalination.

Born in the 1950s at Tennessee’s Oak Ridge National Laboratory, MSR was initially floated as a way to power long-range bombers and deliver nuclear weapons. Led by Weinberg, Oak Ridge’s test reactors in the 1960s resulted in power plant deployment proposals in the 1970s. Critically though, MSR doesn’t easily produce weapons-grade material, and the U.S. favored building the power reactors we have today to secure a constant supply of such material during the Cold War. Research continued in the U.S., Russia, Japan and the U.K., but building plans were all but abandoned as the industry was struck by soul-searching disasters such as Three Mile Island in 1979, Chernobyl in 1986 and Fukushima in 2011.

But the prospects of climate change and the need to find a clean, cheap and abundant power source is now breathing new life into nuclear energy, especially for high-demand growth markets like China. This has led to burgeoning hope in MSR’s potential, culminating in a string of deals and research efforts worldwide that has vastly shortened its development period by at least a decade. “When we produce power cheaper than coal-fired plants, demand will be huge,” says Rory O’Sullivan, lead engineer at Moltex, a British company that’s proposing a simpler version of MSR.

The technology still needs to be proven, of course, but multilateral collaboration is taking off. Oak Ridge, part of the U.S. Department of Energy, is still at the heart of research efforts and is helping China, which has 700 nuclear experts working full time at the Shanghai Institute of Applied Physics on the targeted delivery of a functioning MSR pilot plant by 2020. This will be followed with a demonstration plant by 2025, and a commercial one five years later. But there are also two other proposed designs Oak Ridge is helping get off the ground — one from Canadian startup Terrestrial Energy and another from Alabama-based Southern Company in partnership with the Bill Gates–backed nuclear developer TerraPower, based in Washington state.



“MSRs will be up and running by 2030,” O’Sullivan says. And while Tindale agrees they’re coming soon and will be cheaper than conventional reactors, he warns that it’s still unclear when MSR will be less costly than coal. Much of the uncertainty about MSR can be blamed on regulatory holdups. Getting any nuclear effort off the ground requires government support and guaranteed long-term returns for private investment.

So who will cross the finish line first? There is no technical reason that front-runner China would take more time, says David Eugene Holcomb, a nuclear researcher at Oak Ridge. The problem is simply that China “hasn’t decided yet” whether to double down on its investment in MSR and likely won’t until results are in from the early efforts currently underway, he says.

Tindale says the U.K. is also struggling under regulatory red tape. “If we can remove the bottlenecks, we could have a demonstration plant by the mid-2020s and commercialization by 2030,” he says. But Tindale and his colleagues have an ace up their sleeve: Britain has 140 tons of plutonium — the world’s biggest stockpile — that it may be eager to convert into energy via MSR. “That’s why I’m confident it will get off the ground,” Tindale adds.