Uncapped with Jack AltmanWhy the US Needs Nuclear Energy | Jordan Bramble, CEO of Antares | Ep. 11
CHAPTERS
Nuclear’s origins: Chicago Pile, Manhattan Project, and the military roots of fission
Jordan traces nuclear power back to the first human-made reactor (Chicago Pile, 1942) and explains how early reactor development was tightly coupled to weapons programs. He frames commercial nuclear as an outgrowth of government-led, military-driven R&D rather than a purely private-market innovation.
- •Chicago Pile (1942) as the first reactor; graphite moderation and early criticality experiments
- •Manhattan Project motivation: fission research and plutonium production as a by-product
- •Early production reactors at Savannah River and Hanford supporting the weapons program
- •Core thesis: atomic energy development began as a government/military enterprise that later seeded commercial efforts
From naval reactors to the first civilian plants: Shippingport and early scale
The conversation moves from weapons to propulsion, highlighting Admiral Hyman Rickover and the Naval Nuclear Propulsion Program. Jordan explains how the first civilian power reactor (Shippingport) was effectively a spin-off of naval reactor work, and notes that early civilian reactors were relatively small by today’s standards.
- •Rickover’s naval program and early submarine reactors (Nautilus water-cooled; Seawolf sodium-cooled)
- •Why the Navy standardized on water-cooled designs: maintainability and sodium safety concerns
- •Shippingport (PA) as the first civilian power reactor, built rapidly and derived from naval designs
- •Early grid reactors were “small” (tens to ~100 MW), foreshadowing today’s SMR framing
The broader 1950s–60s nuclear boom: rockets, jets, aircraft, and space reactors
Jordan describes a period of intense experimentation where multiple branches of the US government pursued nuclear propulsion and power. These programs tested nuclear thermal rockets, explored nuclear aircraft concepts, and even launched a fission reactor into orbit—illustrating both ambition and technical breadth.
- •NERVA nuclear thermal rockets: liquid hydrogen heated through a reactor for high efficiency
- •Other propulsion concepts (Rover/Pluto nuclear jet engines; nuclear aircraft ground tests)
- •SNAP-10A (1965): the only publicly acknowledged US space reactor launch, still in orbit
- •Soviet contrast: dozens of space reactors for radar satellites in low Earth orbit
- •Commercial light-water designs ultimately traced back to naval PWR heritage
Why US nuclear buildout collapsed after the early 1970s
Jordan argues the slowdown wasn’t caused by a single factor but by multiple simultaneous shifts—safety incidents, regulatory restructuring, and (in his view underappreciated) major financial and budget changes. He emphasizes how the transition away from large, government-led programs reduced momentum and industrial capability.
- •US built ~100 reactors from ~1950 to early 1970s; only a few since
- •Regulatory changes: Atomic Energy Commission era to DOE creation and NRC independence
- •Safety incidents and public sentiment as contributing factors
- •Major driver: 1970s fiscal/budget austerity and reduced federal R&D intensity
- •Loss of sustained demand degraded workforce, supply chains, and execution capability
The old model vs. today: government megaprograms, and the rise of venture-backed nuclear
Jordan compares the scale of mid-century federal programs to today’s smaller R&D footprint, calling the Naval Nuclear Program a rare remnant of the earlier era. He then positions “startup nuclear” as an emerging pattern where private capital begins to share the burden of technology maturation, similar in starting conditions (not identical arc) to SpaceX-era space commercialization.
- •Historical federal R&D spend (as % of budget) was far higher in the 50s–60s than today
- •Naval reactors still operate with large budgets, dedicated national lab support, and in-house design
- •Shift in defense tech: increasing desire for private capital to co-fund maturation
- •Analogy to space: Apollo-style government leadership followed by decades of stagnation and private recatalyzation
- •Caution: nuclear’s development curve differs materially from rockets, despite surface parallels
What’s driving renewed nuclear interest now: climate, growth/AI power, and security
Jordan outlines today’s main demand signals for nuclear, spanning decarbonization, economic growth needs, and rising electricity demand from AI/data centers. He also adds national security and resilience as a key (and more funded) near-term driver compared with corporate interest that is often still exploratory.
- •Climate: net-zero pathways likely require significantly more fission generation
- •Fusion contrasted with fission: fission is deployable now; fusion remains technically uncertain/timelines long
- •Growth: energy consumption per capita and GDP per capita correlation; argument that progress is energy-limited
- •AI/data centers: transmission buildout challenges and wind/solar density limits push attention back to nuclear
- •National security: grid/cyber resiliency and mission assurance for critical defense assets
- •DoD is putting real dollars into maturation today, more than many commercial buyers
Space becomes a warfighting domain: why space nuclear power matters again
Building on the national security theme, Jordan explains how the weaponization of space increases demand for high-power systems in orbit—particularly directed energy. He argues nuclear power becomes attractive at higher power levels where solar mass and area scale poorly, and ties this to missile defense concepts like space-based intercept.
- •Space Force and shifting posture from redundancy to active space “fires” (offensive capabilities)
- •Directed energy (lasers, high-power microwaves, particle beams) drives demand for scalable onboard power
- •Higher power enables longer engagement distances
- •Solar vs nuclear scaling: solar mass/area scales roughly linearly; nuclear becomes more efficient at higher kW
- •ISS as a reference: ~100 kW with enormous solar arrays; nuclear could shrink footprint significantly
- •Executive-branch interest in missile defense architectures that include space-based elements
SMRs vs microreactors: definitions, sizes, and why Antares targets kilowatt-scale
Jordan clarifies the sometimes-murky definitions of SMRs and microreactors, then situates Antares’ approach at the 200–300 kW level. The key business idea: compete first where power is valuable (resilience, remote logistics, defense missions) rather than as a cheap commodity on the grid.
- •SMR commonly framed as ≤~100 MW; microreactors often ≤10–20 MW, with varying definitions
- •Antares targets ~200–300 kW (truck-bed sized) with even smaller variants for space
- •Factory manufacturability is the promise: smaller reactors reduce site construction complexity
- •Economics differ: microreactors can have fuel as ~40–50% of cost vs single digits for large plants
- •Strategic focus: premium/mission-critical power markets where nuclear’s attributes justify higher price
Defense as the beachhead: mission-critical use cases and ‘thousands of units’ potential
Jordan explains why the DoD is an attractive early customer: willingness to fund maturation and strong need for resilient, distributed power. He highlights missile defense–adjacent facilities, Arctic radar sites, and remote operations where diesel logistics are costly and reliability is paramount.
- •Distributed demand on bases: multiple hundreds-of-kW systems can match real loads and reduce vulnerability
- •Missile defense and mission assurance: power for intercept sites, command/control, launch readiness even without grid power
- •Arctic radar and remote locations: avoid diesel supply chains and high delivered electricity costs
- •Civilian parallels: remote communities paying ~60–80¢/kWh make microreactors comparatively competitive
- •Market sizing intuition: potentially thousands of deployments across defense assets over time
Engineering choices and scaling: heat-pipe-cooled microreactors and modular “banking”
Jordan describes Antares’ heat-pipe reactor approach, emphasizing simplicity (no pumps) and iterative prototyping speed. He notes heat pipes scale poorly past a point due to neutron economy and structural mass, so scaling can come from combining multiple units into a bank rather than endlessly enlarging a single core.
- •Heat pipes invented for space nuclear at Los Alamos; widely used today (laptops, satellites)
- •Operating principle: phase change and capillary return move heat with minimal active components
- •Iteration advantage: faster prototyping vs complex pumped coolant/turbomachinery redesign cycles
- •Scaling constraint: too much metal can absorb neutrons, making larger cores inefficient/oversized
- •Modularity path: combine multiple small reactors to reach multi-megawatt needs
How to sell to the DoD: start from the mission, navigate complex stakeholders, build ahead of budgets
Jordan contrasts defense sales with SaaS, stressing that success requires deep problem discovery and relationship-building long before a product is complete. He explains the fragmented “customer persona” problem—end users, buyers, Pentagon planners, and Congress—and advocates anticipating how budgets will evolve so the product is ready when programs form.
- •Bring product thinking to hard tech: don’t just sell a “box of power,” co-design around mission effect
- •Credibility-building loop: engage early, return with progress, earn deeper access over time
- •Defense buying is multi-actor: user ≠ buyer; policy/planning and congressional appropriations matter
- •Two go-to-market strategies: sell into existing budget lines vs create transformational capability with a future budget
- •Long relationships function like compounding sales channels; expand from initial footholds to adjacent needs
Why Los Angeles is emerging as a hard-tech hub: aerospace legacy, manufacturing, and logistics
Jordan attributes LA’s hard-tech clustering to deep historical roots and practical advantages: an established aerospace/defense workforce, industrial zoning, and shipping/logistics. He connects today’s startup ecosystem to prior eras of aerospace and even nuclear-adjacent work in Southern California.
- •Pre-SpaceX roots: Hughes Aircraft, Boeing and long-standing South Bay aerospace concentration
- •Workforce depth: machinists, welders, and manufacturing talent at national scale
- •Industrial real estate and zoning supportive of manufacturing compared to other tech hubs
- •Logistics advantage: Port of Long Beach and transport routes enable moving large hardware
- •Local nuclear history: Aerojet and SNAP-era work (Santa Susana, Azusa) as part of the region’s legacy
Building a fast hard-tech culture: urgency, multidisciplinary truth-seeking, and hiring for mission
Jordan describes how Antares tries to counteract slow industry/customer tempos by internally setting an aggressive pace and breaking work into tight milestones. He emphasizes cultural mechanisms for multidisciplinary decision-making—avoiding “priest classes,” prioritizing ideas over rhetoric—and recruiting people motivated by the mission’s breadth (security, climate, space).
- •Hard-tech pace is internally set (not pulled by customers); deliberate urgency is required
- •Company target: first reactor on by end of 2027; reinforced daily with milestone decomposition
- •Cultural values: “Just make it happen” and “Let great ideas beat great arguments”
- •Multidisciplinary tension management: manufacturability vs theoretical optimality across engineering domains
- •Hiring thesis: mission attracts “missionary” talent; novelty and momentum differentiate from mature tech stacks
Scaling after first criticality: reliability expectations, iterative test units, and manufacturing ramp
Jordan closes by explaining that turning on the first reactor is only the beginning; achieving nuclear-grade uptime and customer expectations requires multiple test iterations. Antares’ small scale enables repeated builds within venture-financeable budgets, while a parallel effort is needed to scale manufacturing toward high unit volumes.
- •Customers expect nuclear-like capacity factors (high uptime), which won’t be immediate on first units
- •Plan: build multiple test reactors to improve reliability, cost, and build time iteratively
- •Microreactors make iteration financially feasible compared with gigawatt or large-SMR first-of-a-kind costs
- •Manufacturing ambition: ultimately produce 100+ units/year (modest total MW, high assembly volume)
- •Market maturation link: faster technical progress encourages buyers to budget for deployments
