Rosa Del Mar

Daily Brief

Issue 90 2026-03-31

Portable Microreactors Positioning And Commercialization Path

Issue 90 Edition 2026-03-31 9 min read
General
Sources: 1 • Confidence: Medium • Updated: 2026-04-01 03:39

Key takeaways

  • Radiant is building its first nuclear reactor in a roughly 70,000-square-foot facility and has added a second building after increasing vertical integration including in-house machining.
  • Ferrite for high-frequency transformers and thin-film power capacitors are identified as power-electronics supply-chain vulnerabilities due to supplier concentration in Asia, and work is underway to onshore or nearshore production including reviving a former U.S. ferrite facility in Georgia.
  • In the U.S. grid today, power delivery via transmission and distribution is a larger bottleneck than building new generation capacity.
  • It is disputed that data centers will raise electricity rates, based on the argument that high utilization increases total kilowatt-hours delivered over largely fixed delivery costs.
  • U.S. electricity demand is rising again because data centers, electrified transport, and reshoring outpace efficiency gains that previously masked grid underinvestment.

Sections

Portable Microreactors Positioning And Commercialization Path

  • Radiant is building its first nuclear reactor in a roughly 70,000-square-foot facility and has added a second building after increasing vertical integration including in-house machining.
  • Radiant plans to use an 80-acre Tennessee site for fuel handling and loading and then transport fueled reactors to customer sites while pursuing the required regulatory permit path.
  • Radiant is building a mass-producible, portable microreactor with a current product focus on a trailer-sized reactor.
  • Radiant is claimed to be the only company among a new reactor cohort that is permitted to go to full power rather than only to criticality.
  • Radiant claims its five-year microreactor energy output is equivalent to roughly two million gallons of diesel and that the unit can be removed when operations end, shifting waste handling away from the customer site.
  • Radiant expects early production to be mostly conventional assembly work and intends to add factory automation later after iterative learning.

Grid Edge Power Electronics As Scaling Lever

  • Ferrite for high-frequency transformers and thin-film power capacitors are identified as power-electronics supply-chain vulnerabilities due to supplier concentration in Asia, and work is underway to onshore or nearshore production including reviving a former U.S. ferrite facility in Georgia.
  • Heron's first product, Heron Link, is a five-megawatt bidirectional solid-state transformer that converts 800–1500V DC to 34kV AC for distribution and sub-transmission interconnection use cases including data centers, solar, and batteries.
  • Replacing oil-filled line-frequency transformers with high-frequency switched power electronics and software can improve power density and control responsiveness for industrial-scale power conversion.
  • Heron Link uses a modular fail-operational architecture with thirty 165-kW modules per five-megawatt unit so the system continues operating if a module fails.
  • Heron was founded to address a perceived lack of innovation on the grid side of the meter compared to rapid innovation in generation, storage, and loads.
  • Data center grid instability is claimed to be solvable using modern power electronics with grid-forming controls plus modest energy storage so data centers ride through disturbances and can stabilize the grid.

Grid Constraint Shift From Generation To Delivery

  • In the U.S. grid today, power delivery via transmission and distribution is a larger bottleneck than building new generation capacity.
  • Efficiency gains from the 1980s through the 2010s largely offset growth in energy services, keeping net electricity delivered roughly flat over that period.
  • U.S. electricity demand is rising again because data centers, electrified transport, and reshoring outpace efficiency gains that previously masked grid underinvestment.

Data Center Load As Reliability Problem And Power Electronics Solution

  • It is disputed that data centers will raise electricity rates, based on the argument that high utilization increases total kilowatt-hours delivered over largely fixed delivery costs.
  • Gigawatt-scale data centers can create grid stability risk by rapidly isolating from the grid during disturbances, and an example cited is roughly two gigawatts of data centers shutting off in Virginia.
  • Data center grid instability is claimed to be solvable using modern power electronics with grid-forming controls plus modest energy storage so data centers ride through disturbances and can stabilize the grid.

Electrification Scale Expectations And Ai As Demand Driver

  • U.S. electricity demand is rising again because data centers, electrified transport, and reshoring outpace efficiency gains that previously masked grid underinvestment.
  • Electrification is expected to extend beyond transportation to most end uses, requiring the electricity grid to expand by roughly three to five times depending on assumptions.
  • Electricity demand growth is expected to accelerate because AI enables more applications even as compute efficiency improves.

Watchlist

  • Ferrite for high-frequency transformers and thin-film power capacitors are identified as power-electronics supply-chain vulnerabilities due to supplier concentration in Asia, and work is underway to onshore or nearshore production including reviving a former U.S. ferrite facility in Georgia.
  • Bernauer suggests a plausible future architecture where power comes from many intelligent generators and microgrids that dynamically mesh rather than relying only on traditional centralized grid structure.

Unknowns

  • What quantitative evidence shows delivery (transmission/distribution/interconnection) is the dominant bottleneck versus generation in the specific markets being discussed?
  • What are the actual interconnection requirements, certification pathways, and utility acceptance criteria for a 5 MW solid-state transformer at 34 kV, and how many pilots are operating under utility oversight?
  • What are the measured efficiency, thermal performance, fault response behavior, and maintenance outcomes of modular solid-state transformer deployments in realistic grid disturbance scenarios?
  • What is the current permitting status and scope for full-power operation for the microreactor program, and what third-party documentation confirms the claimed differentiation versus peers?
  • What fuel supply, fuel handling, transport, and security constraints apply to centralized fueling and shipment of fueled reactors, and what approvals are required before first fueled delivery?

Investor overlay

Read-throughs

  • Onshoring bottlenecks in grid edge power electronics could shift value to suppliers of ferrite for high frequency transformers and thin film power capacitors if domestic or nearshore capacity is rebuilt and qualified.
  • If transmission, distribution, and interconnection are the dominant constraint, spending and procurement could skew toward delivery upgrades and controllable power electronics rather than only new generation additions.
  • Microgrids and many intelligent generators that dynamically mesh could increase demand for grid forming controls, modular solid state transformers, and software coordinated hardware at distribution voltages.

What would confirm

  • Published quantitative evidence in the discussed markets showing transmission, distribution, or interconnection limits drive delays more than generation availability, plus utility plans and budgets reflecting that shift.
  • Utility overseen pilots of a 5 MW solid state transformer at 34 kV with clear interconnection requirements and certification path, plus measured results for efficiency, thermal behavior, fault response, and maintenance.
  • Documented progress on domestic or nearshore ferrite and thin film capacitor production including facility restart status, qualification milestones, and supply agreements that reduce Asia concentration risk.

What would kill

  • Evidence that generation buildout rather than delivery is the binding constraint in target markets, or that delivery upgrades do not improve capacity or interconnection timelines as expected.
  • Utility acceptance stalls due to unclear certification, unmet interconnection criteria, or poor real world performance of modular solid state transformers during disturbances.
  • Microreactor commercialization slips due to permitting limits, fuel handling and transport constraints, or lack of third party documentation validating differentiation and the deploy remove operating model.

Sources