Swiss-Swedish engineering giant ABB has announced a strategic collaboration with Swedish nuclear startup Blykalla (formerly LeadCold) to explore the integration of small-scale nuclear reactors into maritime propulsion and onboard energy systems. The partnership aims to develop compact lead-cooled fast reactors (LFRs) tailored for commercial shipping and potentially naval platforms—offering a zero-emission alternative with high energy density and long endurance.
Strategic Context: Energy Demands in Maritime Defense and Shipping
The maritime sector faces mounting pressure to decarbonize while maintaining operational range and reliability. For military vessels—especially submarines, aircraft carriers, and future unmanned surface vessels (USVs)—nuclear propulsion offers unmatched endurance without refueling. However, traditional pressurized water reactors (PWRs) used by navies such as the U.S., France, Russia, or China are large, complex, expensive to build and maintain, and politically sensitive for civilian use.
This is where small modular reactors (SMRs) or microreactors come into play. Designed for scalability, passive safety features, rapid deployment timelines, and reduced crew requirements, SMRs offer a potential breakthrough in both commercial shipping decarbonization efforts and next-generation naval vessel design.
Blykalla’s SEALER Technology: A Compact Lead-Cooled Reactor
Blykalla’s flagship technology is the SEALER (Swedish Advanced Lead Reactor), a lead-cooled fast reactor designed specifically for small-scale applications. Unlike conventional water-cooled reactors that require high-pressure systems and active cooling loops, SEALER uses molten lead as a coolant—enabling passive heat removal even in shutdown scenarios.
- Design Output: 3–10 MWe per unit
- Fuel Cycle: Uranium nitride fuel with long core life (~10–30 years)
- Coolant: Liquid lead at atmospheric pressure (~400–500°C operating temperature)
- Safety Profile: Inherent passive cooling; no need for external pumps or pressurization
The SEALER concept was originally developed at KTH Royal Institute of Technology in Stockholm. It has received support from the Swedish Energy Agency as well as private investors including Bill Gates’ Breakthrough Energy Ventures. Blykalla is currently working toward licensing its first land-based demonstration reactor by 2030.
ABB’s Role: Power Systems Integration & Maritime Electrification Expertise
ABB brings deep expertise in shipboard electrification systems—including propulsion motors, power distribution networks (DC grids), automation controls (e.g., ABB Ability™), battery integration management systems (BMS), and containerized energy modules. In this collaboration with Blykalla:
- ABB will assess how nuclear microreactor output can be integrated into existing or new shipboard DC electrical architectures.
- The company will also evaluate safety-critical interfaces between the reactor module and marine control systems.
- The goal is to enable modular installation of LFR-based energy units within containerized or hull-integrated compartments on ships.
This aligns with ABB’s broader strategy of enabling low- or zero-emission marine propulsion through hybrid-electric architectures using batteries, hydrogen fuel cells—or now potentially nuclear microreactors.
Dual-Use Potential: Naval Applications Beyond Civilian Shipping
While the official announcement frames the collaboration around commercial shipping decarbonization goals under IMO targets (e.g., net-zero GHG emissions by ~2050), there are clear dual-use implications for defense customers:
- Unmanned Naval Platforms: Microreactors could enable persistent operation of large USVs or underwater drones without refueling logistics.
- Littoral Combatants & Patrol Vessels: Compact LFRs may offer extended patrol durations without reliance on vulnerable fuel supply chains.
- Auxiliary & Support Ships: Nuclear-powered replenishment ships could reduce fleet carbon footprints while increasing endurance during blue-water operations.
NATO navies have shown interest in small modular reactor concepts—for example through U.S. Department of Defense initiatives like Project Pele (mobile microreactor demonstrator led by BWXT). While Sweden does not currently operate nuclear-powered naval vessels due to legal constraints on military use of nuclear energy under its Atomic Energy Act (1984), this technology development may influence future policy debates across Europe as strategic autonomy becomes more pressing amid global tensions.
Challenges Ahead: Regulation, Safety Certification & Public Acceptance
The path from prototype to deployment remains steep. Key hurdles include:
- Nuclear Licensing: Maritime-specific safety frameworks for floating reactors do not yet exist in most jurisdictions; classification societies like DNV are only beginning to explore standards.
- Sovereign Export Controls: Nuclear technologies face strict export regulations under IAEA guidance; dual-use concerns may limit international sales unless safeguards are robustly implemented.
- Crew Training & Maintenance Infrastructure: Operating even passive reactors requires specialized skills absent from most merchant fleets today—though militaries may be better positioned here.
- Siting & Decommissioning Plans: End-of-life disposal strategies must be factored into lifecycle planning from day one—especially at sea where retrieval logistics can be complex.
Blykalla has stated it aims to achieve full regulatory approval for its land-based SEALER demonstration unit by early next decade—with maritime variants likely trailing behind by several years depending on partner uptake and regulatory harmonization efforts across EU/IMO frameworks.
A Glimpse Into Future Naval Energy Architectures?
This partnership between ABB—a global leader in electrification—and Blykalla—a nuclear innovation startup backed by top-tier investors—marks a significant step toward reimagining how ships might be powered in the coming decades. If successful at scale-up stages beyond R&D demonstrations, compact LFRs could become an enabling technology not just for green commercial fleets but also next-generation autonomous naval platforms demanding persistent onboard power without fossil fuels or frequent resupply missions.
The outcome will depend heavily on regulatory agility, public-private funding mechanisms across NATO/EU frameworks—and whether militaries see enough strategic advantage in adopting inherently safe microreactor designs over traditional diesel-electric configurations or large PWRs that dominate today’s nuclear navies. Either way, this initiative puts Sweden on the map as a serious player in advanced maritime nuclear innovation—civilian or otherwise.
