Cheeky Pint: Julia DeWahl of Antares on Building Nuclear Reactors for the US Military

Date: November 25, 2025
Host: John Collison (Stripe co-founder)
Guest: Julia DeWahl, Co-founder of Antares
Podcast Theme: Candid conversations with founders, builders, and leaders over a pint.

Episode Overview

In this episode, John Collison interviews Julia DeWahl, co-founder of Antares, a company focused on designing nuclear microreactors for critical infrastructure, with a primary emphasis on military and off-grid use cases. The wide-ranging discussion covers Julia’s career trajectory from Opendoor to SpaceX, the motivations and challenges of building nuclear hardware for military applications, the evolving regulatory landscape, supply chain intricacies, and the future of nuclear as an energy source.

Key Discussion Points and Insights

Julia's Early Career and Lessons Learned ([00:12]–[02:46])

• Opendoor:

  • Emphasized the importance of understanding real customer problems.
  • Noted how the team’s lack of experience with home buying led them to conduct informal customer interviews over bagels.
  • Julia: "We just went and sat outside a bagel shop for Saturday and a Sunday morning and just bought people bagels and just asked them about their processes, buying and selling a home and learned a ton and just really thought about what language they were using, what were the pain points." ([00:44])

• SpaceX and Starlink:

  • She led business operations as Starlink moved from R&D to market.
  • First-hand customer feedback via Zoom highlighted how complex the hardware setup was.
  • Realized the importance of removing pain points that engineers might overlook.
  • Led to the creation of a cross-functional "SWAT team" to improve installation and mounting.

• Big Takeaway:

  • "Customers, again, they're just... the reason you start a business." ([01:54])
  • Drew a direct line from these customer-centric lessons to founding Antares for military needs.

What is Antares, and What Are Microreactors? ([02:46]–[04:14])

• Product Focus:

  • Antares is building sub-megawatt (hundreds of kilowatts) nuclear microreactors for critical, off-grid, or resilient backup energy.
  • Target use: Military bases, missile defense sites, anywhere diesel generators are now used.
  • Systems are much smaller than submarine reactors; more like "the size of a car".

• Design Philosophy:

  • Enable mission capabilities not previously possible due to power constraints.
  • Potential applications: underwater drones, remote sensing, and eventually commercial sectors (as costs drop).

• Julia: "Think about replacing a diesel generator that's used to power something that would be on the order of 200 to 300 homes of electricity. So it's quite small." ([04:06])

Market Strategy and Go-to-Market Choices ([05:21]–[06:14])

• Why Start with the Military?

  • Government/military is less price-sensitive—willing to pay a premium for reliability and energy resilience.
  • Early commercial markets (e.g., data centers) could follow once costs drop.
  • Emulates the Starlink approach: “the starlink of electricity” for hard-to-reach places.

• Premium Power Thesis:

  • "Premium power is where you need to go with nuclear."
  • Hyperscalers and data centers are willing to pay above-market for 24/7 clean energy.

Technical Path and Regulatory Milestones ([06:28]–[08:35])

• Near-term milestones:

  • 2026: Criticality test—demonstrates safe initiation of a nuclear reaction.
  • End of 2027: First demonstration unit producing actual power.

• Regulatory Environment:

  • Recent DOE and federal policy shifts are making test deployments more viable.
  • Policy support is stronger than ever for accelerating nuclear innovation.

Market Landscape and Competition ([08:37]–[10:05])

• No commercially available microreactors yet; Antares aims to be among the first.

• Defense use cases are the entry point—mission-critical sites on bases, remote missile defense, etc.

• Future commercial uses: Oil & gas operations, mining, and other remote, high-cost-of-energy sectors.

• Memorable Quote:

  • "There's a famous defense quote: 'Unleash us from the tether of fuel.'" ([10:28])

Why Now? The Nuclear Renaissance ([10:58]–[13:20])

• Historical barriers:

  • Anti-nuclear sentiment in the 1970s/80s was amplified by environmental movements and conflation with nuclear weapons.
  • Regulatory and cost headwinds led to a halt in new nuclear projects.

• Shifting Public Sentiment:

  • Notable recent swing in favor of nuclear energy, especially among youth.
  • Julia: "It reminds me of gay marriage... enough things add up and it just swings and no one ever looks back type of thing. ...The percentage point change we've seen in the last five to ten years is almost 20 points." ([13:01])

• Advocacy Experience:

  • Julia was involved in activism to prevent the shutdown of Diablo Canyon nuclear plant in California, facing off with longstanding anti-nuclear groups.
  • "Our mothers against their mothers. And it's just funny how old school a lot of that opposition is." ([14:21])

Regulatory Revolution ([15:11]–[19:16])

• The Nuclear Regulatory Commission (NRC) once seen as a major roadblock is now becoming more supportive, thanks to bipartisan legislation.

• Major shift: NRC's mandate expanded to consider both safety and overall public benefit.

• New "sandbox" regulatory pathways:

  • Department of Energy (DOE) and Department of Defense (DOD) can now license and test their own reactors, bypassing early NRC requirements.
  • Moves toward faster, more iterative hardware development.

• Julia: "Right now they've changed it to: you have 18 months to get your answer from the NRC—license or no license." ([16:47])

The Future of Clean Energy: Nuclear vs. Renewables ([20:14]–[23:54])

• Julia is skeptical about a single-source future (all-solar or all-nuclear).

• Points out that true 24/7 clean energy (without natural gas backup) is currently as expensive for solar+batteries as for nuclear.

• Nuclear offers advantages in energy density and supply chain diversity.

• The US currently gets ~18% of its electricity from nuclear.

• Julia: "France made a very, very deliberate decision to actually go to 70%... because they had no carbon resources." ([23:07])

• "Uranium... is so much easier to store. It's a million times as dense as coal." ([23:20])

Nuclear Fuel Supply Chain ([24:55]–[26:43])

• Most uranium enrichment happens overseas; only a tiny portion is US-mined.

• Recent push to reshore both mining (e.g., Texas, Wyoming) and enrichment.

• New entrants like General Matter (a Founders Fund-backed startup) are innovating in uranium enrichment.

• Julia: "I think you just want diversity; you don’t want everything from one place." ([26:33])

Founding Antares: Geopolitics and Opportunity ([26:43]–[29:20])

• Julia’s nuclear interest was catalyzed by the Ukraine invasion, the energy price crisis in Europe, and seeing the consequences of Germany shutting down its nuclear fleet.

• Social media research connected her with co-founder Jordan, whose vision was military microreactors.

• Antares’ “beachhead” is military where pricing is less competitive and the need is greatest.

• Julia: "I didn’t know the difference between fission and fusion, honestly, at the time." ([27:14])

Fundraising, Competition, and Commercial Models ([30:25]–[34:47])

• Fundraising:
  • Early investment is buoyant thanks to nuclear’s trendiness, but will be milestone-driven as hardware progress is expected.
• Competition:
  • Numerous startups are in the nuclear space, often targeting different sectors—Antares is focused on the smallest scale and defense.
• Government as Customer:
  • Army’s Janus program is modeled on the milestone-based COTS contract used for SpaceX, funding several companies then selecting winners.
• Government Contracting:
  • The traditional “cost-plus” model is acknowledged as problematic; the military is eager for innovation and new models.

Building a Hard Tech Startup: Challenges and Red Tape ([34:47]–[36:09])

• Recruiting:
  • Competes with brand-name employers like SpaceX for talent.
• Regulatory Hurdles:
  • Despite improvements, working with national labs and building physical hardware adds significant cost and red tape.
  • "Sometimes it’s just through," when asked about finding workarounds.

Vision for US Energy Policy and Government Role ([36:09]–[39:53])

• Julia advocates for the US government to act as a buyer and create public-private partnerships, citing the new $80 billion nuclear partnership with Westinghouse as a positive sign.
• These procurement commitments give the nuclear industry direction and catalyze investment.
• Recent moves (e.g., Brookfield Asset Management investing in nuclear projects) reinforce momentum.

Manufacturing, Supply Chain, and Talent ([39:55]–[42:24])

• Limited suppliers for nuclear-grade materials; often sourced internationally (e.g., Japanese graphite).

• Talent: LA region has many hard-tech opportunities, so mission and differentiation are key to recruiting.

• Julia: "If you want to work at SpaceX... we've lost you. But if you're interested in nuclear... that's a compelling piece." ([42:09])

Exciting Trends in Nuclear ([42:36]–[43:31])

• Reactivating recently shuttered nuclear plants (e.g., Dwayne Arnold, Three Mile Island) in partnership with big tech firms like Google and Microsoft.
• The sudden spike in grid demand (especially from data centers) is creating opportunities for all generation sources—nuclear, solar, and gas—all now backlogged.

Company Culture at Antares ([44:23]–[45:12])

• Strives for a culture of excellence and results-oriented accountability.

• Takes inspiration from SpaceX’s intensity but values positivity and energy in the workplace.

• Julia: "Ultimately I would be proud to be delivering on an excellent product that can be delivered to market soon. Right. And we can all go use." ([45:06])

Notable Quotes

• On the military energy challenge:
  "Our missile defense sites are sitting there being powered by diesel generators still. Like, shouldn't we upgrade that?" ([01:51])

• On changing attitudes toward nuclear:
  "It's just huge public sentiment shift. And I think the kind of the old hippie nuclear testing, nuclear weapons testing folks are kind of dying out." ([13:20])

• On the regulatory shift:
  "The biggest thing they did was they changed the mandate of the NRC and they said you are no longer focused just on safety because what's the safest number of nuclear reactors to license? Zero." ([15:32])

• On the startup approach:
  "If you are unsure about something, if you're questioning something, you should probably stop and dig into it. We had this thing called the five whys... that on steroids." ([29:26])

• On hard tech vs. software startups:
  "When you have to work with the real world, you have to, you know, you have to kind of play their games a little bit and you have to follow the process in some ways. And there's not always a way kind of around it. Sometimes it's just through." ([36:09])

• On early inspiration:
  "I didn’t know the difference between fission and fusion, honestly, at the time... but it just was one of those like completely undercelebrated, under-championed by anyone." ([27:14])

Important Timestamps

• Early career and SpaceX lessons: [00:12]–[01:54]
• Antares mission and microreactor explanation: [02:46]–[04:14]
• Go-to-market strategy (why military): [05:21]–[05:51]
• Market and regulatory pathway: [06:42]–[08:25]
• Shifting public and regulatory perception: [12:47]–[15:32]
• DOE/Trump-era regulatory sandboxes: [17:43]–[19:16]
• Energy futures, why nuclear diversity matters: [20:14]–[23:54]
• Uranium supply chain: [24:55]–[26:43]
• Antares founding story: [26:43]–[28:24]
• Fundraising and competition: [30:25]–[34:47]
• Hard tech challenges and red tape: [34:47]–[36:09]
• Government as buyer and public-private partnerships: [36:28]–[39:53]
• Supply chain and talent in hard tech: [39:55]–[42:24]
• Trends in nuclear and grid demand: [42:36]–[44:11]
• Company culture: [44:23]–[45:12]

Final Thoughts

This episode offers a comprehensive, candid look at the challenges and excitement of building next-generation nuclear technology for high-stakes uses. Julia DeWahl delivers frank insights on government contracting, regulatory shifts, technical and fundraising hurdles, and the culture she hopes to foster at Antares. For anyone curious about the new wave of nuclear innovation or the intersection of startups and national security, this is a must-listen conversation.