The New Nuclear: How TerraPower Is Powering the Future of Clean Energy

During Earth Week at Columbia Business School, Chris Levesque, President and CEO of TerraPower, laid out a bold vision for the future of nuclear power. 

In conversation with Columbia Climate School Dean Alexis Abramson, Levesque described how TerraPower—founded in 2006 by Bill Gates—is using next-generation technology to make nuclear energy safer, more affordable, and essential to meeting global sustainability goals.

Levesque, who has more than 30 years in the nuclear field, served as a nuclear submarine officer in the U.S. Navy, as well as in leadership roles at Westinghouse and AREVA, and has extensive experience overseeing major reactor projects in the U.S. and Finland.

Now, as the leader of TerraPower for more than a decade, his insights offer a compelling case for why nuclear must play a central role—and how innovation and advanced manufacturing can finally overcome nuclear’s historical barriers of cost, speed, and perception.

Reinventing Nuclear: The Natrium Reactor Advantage

TerraPower has spent nearly two decades developing its flagship Natrium — Latin for sodium — reactor, a fourth-generation nuclear system designed to address two critical challenges: cost and safety. Traditional water-cooled reactors, Levesque explained, require massive high-pressure vessels and thick concrete containment buildings, leading to soaring upfront capital costs and decade-long construction timelines.

Instead of producing steam for electricity immediately, Natrium reactors first heat a massive tank of molten sodium, creating a “thermal battery” that stores energy for when demand peaks.

This flexibility allows TerraPower to deliver electricity precisely when prices are highest, boosting plant profitability while supporting grid stability—a vital capability in an era of fluctuating renewable energy supplies. "Energy storage gave us almost an unanticipated benefit," Levesque said. "It allowed us to separate the nuclear and non-nuclear parts of the plant, significantly reducing costs and regulatory hurdles."

In addition to cost and safety advantages, Natrium's design also allows for unprecedented flexibility in plant siting and scalability. Without the need for massive water supplies or specialized high-pressure infrastructure, Natrium reactors can be deployed closer to demand centers, retiring coal plants like where they are building their first plant in Wyoming, and adapted for modular, factory-built manufacturing. This flexibility not only shortens construction timelines but also creates economic opportunities for regions transitioning from fossil fuels to clean energy, giving Natrium a critical edge in the race to decarbonize.

Meeting Exploding Global Energy Demand

While renewable energy sources like solar and wind are vital, Levesque emphasized that they alone cannot meet the surging global electricity demand. With the rise of AI, data centers, electric vehicles, and efforts to lift billions out of energy poverty, demand for renewables is expected to triple by 2050.

“We need a portfolio, and nuclear is a really important part of the portfolio,”  Levesque said, citing an MIT study showing that integrating nuclear into energy grids lowers overall system costs by about 20%. Nuclear’s “power density” is a crucial differentiator: a uranium fuel pellet the size of a pinky tip can produce as much energy as a railcar full of coal, according to Levesque. This energy density not only reduces land use but also provides a resilience advantage, especially in politically volatile regions.

"When you load the fuel, you’ve loaded two winters' worth of heat. You can't have interruption due to a problem with a pipeline or a railway,” Levesque said.

Moreover, nuclear energy offers a critical hedge against the intermittency challenges inherent in some renewable sources. While solar and wind output can fluctuate dramatically with weather patterns and time of day, nuclear provides a stable, 24/7 baseload supply. 

This reliability is particularly important as industries and economies increasingly digitize, requiring uninterrupted power for everything from data centers to advanced manufacturing hubs. Without nuclear energy in the mix, achieving both deep decarbonization and grid reliability will become exponentially harder and more expensive, Levesque noted.

Scaling Nuclear: Merging AI, and Human Capital

Scaling nuclear energy to meet future demand will require innovation not just in technology, but also in workforce development and manufacturing processes, according to Levesque. TerraPower’s Natrium reactor design, built from the ground up using multiphysics computer models, is ideally suited for integration with AI and digital twin technologies. 

"The day we turn the reactor on—with a thousand sensors,—AI will be learning from the reactor as it goes online," Levesque explained.

Advanced computing will play a major role in optimizing maintenance, simulating supply chains, and scaling production from one plant per year to as many as ten—a critical leap if nuclear is to become a cornerstone of the global energy system. However, Levesque noted that technology alone isn't enough.

A significant bottleneck remains in human capital. With much of the nuclear workforce inexperienced in new build projects, TerraPower faces the challenge of growing and training the next generation. To bridge this gap, TerraPower is designing reactors that require less onsite labor and partnering with community colleges to expand the skilled trades pipeline. 

“We should worry about not having enough people to power our economy,” Levesque said.

Similarly, while some sophisticated components will be sourced globally—including manufacturing partnerships in Korea—revitalizing the U.S. nuclear supply chain remains an urgent priority. Building a resilient ecosystem of trained workers and advanced factories will be essential to realizing nuclear’s promise.