India’s Bhabha Atomic Research Centre (BARC) is embarking on a pioneering initiative to develop two advanced nuclear reactor models rated at 55 MW and 200 MW. While these compact reactors are designed primarily for captive power generation in energy-intensive industrial sectors such as cement and steel, their size, thermal efficiency, and modular configuration make them potentially adaptable for marine propulsion.

The possibility of integrating such reactors into commercial ships could mark a major leap toward nuclear-powered shipping, reducing dependence on fossil fuels and enhancing energy autonomy for large vessels.

The reactors under development are based on small modular reactor (SMR) principles, enabling flexible deployment across a range of environments, including onshore industrial complexes and maritime platforms.

The feasibility of adapting these Indian reactors for commercial shipping rests upon three major pillars — thermal efficiency, safety design, and refuelling longevity — all of which are central to operational viability and international acceptance under evolving maritime safety frameworks.

BARC’s modular reactors are expected to employ advanced fuel cycles and compact pressurised or pool-type configurations, optimised for passive heat removal and inherent safety. With a projected thermal efficiency of around 30–33% for marine adaptation, they are comparable to international SMR concepts such as the American NuScale system (77 MW electric, ~33% efficiency) and South Korea’s SMART reactor (100 MW, 31% efficiency). Thermal optimisation in BARC designs could leverage India’s experience with naval nuclear propulsion systems, potentially allowing a higher power-to-volume ratio suited to maritime hull integration.

A comparative snapshot of reactor parameters highlights these trends:

ParameterBARC Reactor (Proposed)NuScale (USA)SMART (South Korea)RITM-200 (Russia)Rolls-Royce Micro Reactor (UK)
Rated Output55 MW / 200 MW77 MW100 MW175 MWth / 55 MWe10–50 MW
Reactor TypeCompact PWR / Pool-typeIntegral PWRIntegral PWRPWR (maritime-optimised)High-temp modular core
Efficiency30–33% (est.)33%31%32%35% (target)
Refuelling Interval10–20 years (est.)10–12 years10 years7 years10–15 years
Safety SystemPassive circulation, decay heat removal, dual containmentPassive, modular containmentPassive and redundantDual-loop with passive coolingSolid-state passive
ApplicationsIndustrial / MaritimeLand-based powerDesalination / PowerIcebreakers / TransportMobile / Remote power

Safety remains the most critical design dimension. BARC’s reactors are anticipated to use high-density fuel assemblies coupled with passive emergency core cooling and self-sustaining decay heat removal. By minimising dependence on external pumping or control systems, these features significantly reduce meltdown risk during marine operations.

Comparable measures are found in Western counterparts like the UK Rolls-Royce micro-reactor and Russia’s RITM-200 series used on icebreakers — both relying on passive systems and modular containment. For global certification, BARC’s reactors would require validation from classification entities such as DNV or Lloyd’s Register, involving assessments of containment integrity under vibration, collision, and seawater exposure scenarios.

SMRs are valued globally for their safety features, scalability, and reduced footprint compared to conventional nuclear plants. For BARC, adapting these designs to marine use would demonstrate India’s capability to harness compact nuclear systems for both civilian energy resilience and advanced marine applications.

A fundamental challenge lies in translating land-based reactor technology into a marine-grade propulsion system. The integration process demands rigorous safety standards, naval architectural redesigns, and specialised thermal management systems to cope with dynamic conditions at sea.

However, recent progress in nuclear miniaturisation and passive safety systems significantly strengthens the feasibility of such installations. The inherent longevity of nuclear fuel—allowing ships to operate for years without refuelling—translates to lower operational costs and reduced logistical dependence on bunkering infrastructure.

International developments reinforce the timeliness of India’s initiative. The International Maritime Organization (IMO) has recently approved amendments to the SOLAS Convention under MSC 110, facilitating the regulatory incorporation of emerging technologies such as SMRs into maritime safety frameworks.

This regulatory evolution signals growing institutional acceptance of nuclear propulsion as a viable tool for a decarbonised shipping industry.

Industry leaders and classification societies have echoed this optimism. Christopher J Wiernicki, Chairman and CEO of the American Bureau of Shipping, emphasised during global forums such as the ARGO Summit and London International Shipping Week 2025 that nuclear power is moving from concept to actionable solution.

Similarly, Lloyd’s Register has partnered with Deployable Energy to explore safe reactor integration pathways, while DNV and IACS have issued comprehensive assessments outlining technical, regulatory, and operational requirements for deploying nuclear propulsion in merchant fleets.

For India, the potential adaptation of BARC’s 55 MW and 200 MW reactors for ship propulsion could establish a new paradigm in maritime sustainability. Such nuclear-powered vessels would offer immense endurance, drastically cut emissions, and position the nation as a leader in next-generation clean propulsion technologies.

While extensive testing, international certification, and maritime-specific engineering remain essential, the scientific and regulatory momentum now converging globally indicates that BARC’s modular reactor programme could indeed become a credible proposition for the future of commercial shipping.

IDN (With Agency Inputs)