Skip to Content
Climate change and energy

A nuclear startup will fold after failing to deliver reactors that run on spent fuel

September 25, 2018

Transatomic Power, an MIT spinout that drew wide attention and millions in funding, is shutting down almost two years after the firm backtracked on bold claims for its design of a molten-salt reactor.

High hopes: The company, founded in 2011, plans to announce later today that it’s winding down.

Transatomic had claimed its technology could generate electricity 75 times more efficiently than conventional light-water reactors, and run on their spent nuclear fuel. But in a white paper published in late 2016, it backed off the latter claim entirely and revised the 75 times figure to “more than twice,” a development first reported by MIT Technology Review.

Long delays: Those downgrades forced the company to redesign its system. That delayed plans to develop a demonstration reactor, pushing the company behind rival upstarts like TerraPower and Terrestrial Energy, says Leslie Dewan, the company’s cofounder and chief executive.

The longer timeline and reduced performance advantage made it harder to raise the necessary additional funding, which was around $15 million. “We weren’t able to scale up the company rapidly enough to build a reactor in a reasonable time frame,” Dewan says.

Transatomic had raised more than $4 million from Founders Fund, Acadia Woods Partners, and others. 

Next steps: Dewan stresses that the company’s designs still provide significant advantages over conventional reactors, including far less waste generation and improved safety. She says Transatomic will open-source all its intellectual property, making it available for other researchers to “continue the work that we’ve started and hopefully build on it." 

Josh Freed, vice president for the clean energy program at the centrist think tank Third Way, said Transatomic’s closure doesn’t reflect any broader challenges for advanced nuclear power in general. He notes that dozens of such US projects have emerged in recent years, the Nuclear Regulatory Commission has taken steps to streamline its approval process, and firms like NuScale and Terrestrial are working their way through government reviews.

Instead, it could mark the beginning of the inevitable consolidation period that occurs in any nascent sector as support and momentum builds behind the most promising players, he says.

Deep Dive

Climate change and energy

Harvard has halted its long-planned atmospheric geoengineering experiment

The decision follows years of controversy and the departure of one of the program’s key researchers.

Why hydrogen is losing the race to power cleaner cars

Batteries are dominating zero-emissions vehicles, and the fuel has better uses elsewhere.

How virtual power plants are shaping tomorrow’s energy system

By orchestrating EVs, batteries, and smart home devices, VPPs can help make the grid cleaner and more efficient.

The problem with plug-in hybrids? Their drivers.

Plug-in hybrids are often sold as a transition to EVs, but new data from Europe shows we’re still underestimating the emissions they produce.

Stay connected

Illustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at customer-service@technologyreview.com with a list of newsletters you’d like to receive.