Julia DeWahl
Microreactor Founder, California Nuclear Advocate, Angel Investor
California nuclear activist Julia DeWahl invests in nuclear companies as an angel investor, fought to save Diablo Canyon Nuclear Plant from premature closure, and is developing microreactors for various applications as the co-founder of Antares.
DeWahl sees nuclear energy as indispensable for ensuring a safer, healthier planet for her children — and for generations to come. She says motherhood sharpened her focus on energy’s role in shaping the future, prompting her to think in longer time horizons.
“It's so fundamental to everything we do. And if you look at the developing world, the thing they lack often is energy. Energy poverty is at the root of poverty,” DeWahl said. “It made me think a world with more energy is a better world, and a world that has more sustainable energy is a better world.”
DeWahl, who grew up in Connecticut, studied history at Dartmouth, where she examined the forces that shape nations and economies. She concluded that abundant resources are the foundation of prosperity — a lesson she has carried into her nuclear advocacy. For her, nuclear energy is capable of sustaining economic growth while safeguarding the environment for future generations.
In comparing the paths of Germany and France, DeWahl found a case study in favor of nuclear energy. France, in the 1970s put massive state momentum behind a push for nuclear energy, in response to the oil crisis and domestic energy resource scarcity. As a result, France emerged with the greatest percentage of nuclear on the electricity in the world, making significant steps toward decarbonization, with over ⅔ of generation coming from clean nuclear.
By contrast, DeWahl said she was befuddled that a self-proclaimed environmentally conscious country like Germany decided to phase out their entire fleet - 36 reactors and over 26 GW - from 2002 til 2023. Germany planned to eventually phase out coal, while increasing renewables and using natural gas as a bridge fuel to a renewable grid. The Russia-Ukraine war disrupted their plan for cheap Russian imports.
“Is there something horrible that I’m missing? Why would Germany want to turn off a perfectly good power source that’s also carbon free. I realized how much nuclear had become a cultural lightning rod over time,” DeWahl said. “How come I never hear about nuclear? Why is everyone always talking about renewables, renewables, renewables. There must be something I'm missing, right?”
Around 2021–2022, as DeWahl began researching nuclear energy independently, she discovered the Save Diablo Canyon campaign. This discovery transformed her into a passionate nuclear activist. A growing coalition of pro-nuclear environmental groups—including Save Clean Energy, Mothers for Nuclear, Californians for Green Nuclear Power, Environmental Progress, and Stand Up for Nuclear—was working to prevent the planned 2025 closure of Diablo Canyon Nuclear Plant.
DeWahl said shutting down the plant would have been a “disaster”. The state already faced blackouts, and when San Onofre shut down in Southern California, they turned on natural gas plants in the LA area, increasing emissions. While DeWahl supported a renewable build out, renewables could not make up for losing around 10% of the state’s electricity, provided by Diablo Canyon, overnight.
Desperate to do something to save the large source of clean energy, DeWahl reached out to the Save Diablo Canyon group and Mothers for Nuclear, looking for advocacy outlets. DeWahl gave testimony at the State Senate, and wrote an essay that she released on Twitter and her personal website as a nuclear primer for people looking into the topic. She offered books, resources, and practical pro-nuclear policy recommendations.
On September 1, 2022, the California legislature voted to save Diablo Canyon, extending its lifetime by five years. DeWahl and other California advocates stayed up all night to watch the votes come in and, ultimately, celebrate the victory.
Fresh off the Diablo success, DeWahl wanted to do more. DeWahl was introduced to Jordan Bramble, who shared a passion for nuclear energy and foresaw a wide array of nuclear applications including large plants, space travel, energy security, and remote locations. Bramble believed there was a market opportunity in nuclear by going small, developing a microreactor, and the pair founded Antares together in 2023.
Antares is building a sodium heat pipe cooled reactor with a graphite moderator, using a nitrogen brayton cycle for the conversion system. The design is intended for smaller reactors and has passive safety characteristics that give resilience in low pressure and austere conditions.
The reactor, which just completed its first electrically heated demonstration unit at NASA’s Marshall site, is expected to be complete in 2027. The microreactor is meant to replace diesel generators in remote regions, provide reliable security at locations of national security importance, and propel space travel. The DOD has shown significant interest in the reactor.
Some of the first microreactors in the US are slotted to be tested in 2027 at Idaho National Lab. DeWahl expects to see manufacturing type scale by the early 2030s. At the beginning, microreactors will not be cost-competitive with grid scale power, DeWahl said, but that they will be seen in special locations or uses, like the arctic and submarines.
While DeWahl is passionate about the potential of microreactors, she still recognizes the need for large scale nuclear development. Bramble and DeWahl’s business strategy hinges on the ability to build in a factory and eventually mass-produce.
“I'm still very passionate and excited about grid scale power and gigawatt plants and hugely supportive of that. I actually understand the people who kind of scoff at microreactors, and they're like ‘why not just build more gigawatt scale plants?’”DeWahl said. “Because I also am like, yes, we should do that, but for me and for Jordan, we actually felt better suited to go after the micro reactor unit.”
Along with Antares and legislative outreach, DeWahl said she is proud of her work in shifting perception in the business and venture capital community. An angel investor since 2018, DeWahl helped people take investment in nuclear power companies seriously.
“People weren't really taking it seriously to invest in in nuclear power companies. The piece I wrote and some of the work I'm doing actually brought people's attention to the space a little bit more such that it can be an investable category and to be something people can get into,” DeWahl said. “I'm proud of just being that one small drop in the bucket of changing public perception.”
DeWahl’s passion for nuclear advocacy is deeply rooted in her concern for her three young sons, aged four, two, and seven months. Though still small, they already have a basic awareness of her work. She takes care to explain electricity and different energy sources to them in ways they can understand.
“It's like, ‘Hey, this is how your, your light switch goes on. This is how your toaster works. Like it needs power, right? And somebody and something has to create that power. And there's a few ways to do it. So it almost seems like magic,” DeWahl said. “There are these little, teeny atoms, and it creates energy. It's a little hypothetical and it sounds almost like this magical thing, compared to, well, you burn some coal.”
DeWahl also tries to impress the importance of clean energy early on in her children, describing the smoke and harmful fumes sources like coal and gas create, compared to solar, wind, and nuclear. Another way DeWahl helps her sons conceptualize energy is by comparing the quantity of coal compared to the quantity of nuclear for the same amount of energy – a pellet of uranium, the size of a gummy bear, creates the same amount of energy as one ton of coal, a massive pile in the backyard.
DeWahl’s most immediate goal is for Antares to cross the threshold and begin building, fueling, and producing energy with its first reactor. While significant pro-nuclear momentum exists, DeWahl emphasized the need for real builds.
“So getting some real hardware wins under the belt, where we turned on a reactor, we built that and it works. Getting to that milestone is the number one priority for me,” DeWahl said. “We will figure out the manufacturing at scale, bringing it to all these other places. Once we can prove we can build one, there's going to be investor interest, there's going to be customer interest. There's going to be a line around, around the block waiting for this product that has so many benefits to it.”
Recent bipartisan support for nuclear gives DeWahl optimism and hope for a nuclear revival across the United States.
“It's so easy for so many issues to become so divisive, and you find people just get so entrenched in their side, they won't even look at the other side. And it's so nice that nuclear has brought together Republicans and Democrats, left and right, people who would never normally share the same room together,” DeWahl said. “It really is such a breath of fresh air in what can be just a very politically divisive time.”
Article by Jack Austin