ABB and Blykalla Partner to Explore Nuclear Microreactors for Maritime Propulsion

Global engineering firm ABB and Swedish nuclear technology startup Blykalla have announced a strategic partnership to explore the application of small modular reactors (SMRs) in maritime propulsion. The collaboration focuses on integrating advanced nuclear microreactor designs into shipboard power systems as a potential zero-emission alternative for long-range commercial and naval vessels.

Strategic Context: Decarbonizing Maritime Power

The maritime sector is under increasing regulatory pressure to reduce greenhouse gas emissions in line with International Maritime Organization (IMO) targets. While battery-electric and hydrogen fuel cell systems are gaining traction for short-sea shipping and ferries, long-haul vessels remain heavily reliant on fossil fuels due to energy density constraints. Nuclear propulsion—historically reserved for submarines and aircraft carriers—is being re-evaluated as a viable option for commercial fleets through the use of compact SMRs.

ABB’s involvement signals growing industrial interest in scalable nuclear technologies as part of the broader energy transition. The company brings expertise in marine automation, electrical integration, and vessel powertrain systems. Blykalla (formerly known as LeadCold), a Stockholm-based startup spun out from KTH Royal Institute of Technology, specializes in lead-cooled fast reactor (LFR) designs optimized for modularity and passive safety.

Blykalla’s SEALER Technology: A Maritime Fit?

At the core of the partnership is Blykalla’s SEALER (Swedish Advanced Lead Reactor) concept—a compact LFR designed to operate at high temperatures with minimal maintenance over 10–30 year lifespans. Unlike conventional pressurized water reactors (PWRs), SEALER uses molten lead as both coolant and radiation shield. This allows operation at atmospheric pressure with enhanced thermal efficiency and inherent safety characteristics such as walk-away shutdown capability.

Blykalla has developed multiple variants of SEALER tailored for remote Arctic communities and industrial applications. For maritime use cases, the key advantages include:

• Compact footprint: Suitable for integration into ship hulls without major redesigns
• Long core life: Enables operation without refueling during vessel service cycles
• Passive safety: Reduces reliance on complex active cooling or crew intervention
• No high-pressure systems: Simplifies containment requirements aboard ships

The reactor design is currently undergoing pre-licensing activities with Sweden’s Radiation Safety Authority (SSM). A land-based prototype is planned by 2030 under Sweden’s national innovation program supported by Vinnova.

ABB’s Role: Electrical Integration & Marine Systems

The collaboration will initially focus on conceptual integration studies—evaluating how SEALER reactors could be embedded into existing or future shipboard power architectures. ABB will contribute its experience in marine electrification platforms such as Azipod propulsion units, DC grid systems, energy storage integration, and automation controls.

This includes addressing challenges unique to nuclear-powered commercial vessels such as:

• Power conversion: Matching reactor thermal output with electric drive requirements
• Siting & shielding: Ensuring safe placement within hull constraints while maintaining crew safety zones
• C4ISR implications: Integrating reactor monitoring into ship command/control networks securely
• MRO logistics: Planning lifecycle support without frequent drydocking or refueling stops

Civilian vs Naval Applications: Diverging Paths?

Nuclear propulsion has long been a fixture in naval fleets—particularly submarines—due to its unmatched endurance profile. However, civilian adoption has been limited by regulatory hurdles, public perception issues, port access restrictions, and cost concerns.

The ABB-Blykalla initiative appears focused on civilian shipping use cases initially but could have dual-use implications if adapted for auxiliary naval vessels or unmanned surface ships requiring persistent power generation far from base support.

A recent U.S. Department of Defense initiative—the Project Pele mobile microreactor program—demonstrates parallel interest in deployable nuclear units for expeditionary bases or future autonomous platforms. While not directly connected to this European effort, it underscores growing cross-sector momentum around compact nuclear energy solutions.

Regulatory & Safety Landscape Remains Key Challenge

A major barrier remains international regulation governing nuclear-powered merchant ships. The IMO’s SOLAS Convention permits such vessels but imposes strict conditions under Chapter VIII provisions aligned with IAEA guidelines. Additionally:

• Nuclear liability frameworks: Differ across jurisdictions; many ports lack clear protocols for docking nuclear-powered ships
• Crew licensing/training: Would require new standards blending maritime engineering with nuclear operations expertise
• SAR & emergency response planning: Must account for radiological contingencies at sea

Blykalla has stated that their design philosophy prioritizes proliferation resistance and minimal radioactive waste generation through closed fuel cycles using uranium nitride fuel—a factor that could ease some regulatory concerns if validated through testing.

Toward Demonstration by 2030?

The ABB-Blykalla partnership remains at an early stage focused on feasibility assessments rather than immediate deployment timelines. However, both companies are targeting demonstration milestones before the end of this decade aligned with Sweden’s national innovation roadmap.

If successful—and if international regulatory harmonization progresses—the first generation of SMR-powered cargo or research vessels could enter service sometime after 2035–2040 depending on licensing outcomes and customer demand from sectors like Arctic logistics or offshore infrastructure support where range/endurance trumps port access frequency.

Outlook: A Niche but Strategic Disruption?

Nuclear microreactors are unlikely to replace diesel engines fleet-wide due to cost/complexity barriers—but they may carve out strategic niches where other zero-carbon technologies fall short. These include polar routes opened by melting ice caps; deep-sea mining support; subsea cable laying; or persistent ISR platforms requiring uninterrupted onboard power over months-long missions.

The ABB-Blykalla alliance represents one of several emerging efforts globally—from Korea’s SMART reactor program to U.S.-based NuScale’s marine concepts—to adapt terrestrial SMRs into seaborne formats fit-for-purpose in a decarbonized but operationally demanding future fleet landscape.