Russia’s nuclear energy company, Rosatom, whose subsidiaries built the Kudankulam nuclear power plants in Tamil Nadu, says it has rich experience in ‘small modular reactors’ (SMR), which are the in-thing in clean energy today. The company says its SMR technology can be integrated into regions with limited grid infrastructure or phased-out coal plants. Edited excerpts from interview over email with Vijay Joshi, Head of Business, Rosatom South Asia:
There are many SMR designs globally. What are some of the common features?
SMRs are gaining global momentum, with over 70 designs currently under development across various countries. These compact, flexible nuclear reactors are designed for contexts where large-scale nuclear power plants (NPPs) may not be practical, such as remote locations, islands, or areas with limited grid connectivity. SMRs vary in terms of coolant type (such as pressurised water or gas), deployment models (including onshore, offshore, or submerged), and power output, which typically ranges from a few megawatts to around 300 MW.
What makes SMR NPPs particularly attractive is their combination of lower capital investment and shorter construction timelines. Their modularity and the ability to scale up generation capacity by adding reactor modules as needed allow for quicker deployment and cost efficiency. Many SMR NPPs are also designed to operate in a load-following mode, complementing intermittent renewable energy sources. Beyond electricity generation, they serve multiple purposes such as district heating, seawater desalination, and providing thermal energy for industrial processes.
Describe Rosatom’s SMRs?
Rosatom’s SMR NPP offering is led by the RITM-200 series, a new-generation integral pressurised water reactor (PWR) with an electrical capacity of 55 MW and thermal capacity of 190 MW. Building on decades of experience in operating small reactors in Russia’s nuclear icebreaker fleet, the RITM-200 design has been deployed on icebreakers such as the Arktika, Sibir, Ural and Yakutia. It is now being adapted for both onshore and offshore civilian energy applications, making it the cornerstone of Rosatom’s SMR NPP portfolio.
The RITM-200 reactors have a design life of 60 years and offer long refuelling cycles — six years for land-based installations and up to 10 years for floating variants. With a capacity factor of 90 per cent and fuel based on low-enriched uranium (20 per cent), these reactors provide a stable, low-carbon energy source.
Safety is a central feature of the RITM-200 series, which employs a defence-in-depth approach incorporating both active and passive systems. These include natural circulation-based residual heat removal, hydraulic accumulators for loss-of-coolant accidents, and redundant containment cooling mechanisms. Designed for rapid deployment and scalability, Rosatom’s RITM-200 series stands out as one of the most commercially advanced SMR NPP technologies available.
SMRs are typically designed for “passive safety” — internal metal lining, water and boron flows in case of an accident. Do Rosatom’s designs incorporate these?
Rosatom’s RITM-200 series reactors stand out for their robust, multi-layered safety architecture, rooted in decades of accident-free operation across both land-based VVER reactors and compact nuclear reactors used in Russia’s icebreaker fleet, amounting to over 438 reactor-years of experience. This deep operational legacy directly informs the safety-first design of the RITM-200 and its land-based variant, the RITM-200N.
The RITM-200N reactor integrates active and passive safety systems. Passive systems such as natural circulation-based residual heat removal and hydraulic accumulators can operate independently of external power, maintaining safe conditions for at least 72 hours in the event of a loss-of-coolant accident (LOCA) combined with a complete station blackout, a scenario like Fukushima. These are complemented by active safety mechanisms to provide redundancy, while the reactor’s defence-in-depth design includes multiple physical barriers and containment systems to prevent radioactive release.
Rosatom also incorporates probes in the primary circuit to detect coolant loss and uses control samples made from the same steel as the reactor vessel to monitor material integrity over time, an additional layer of diagnostics rarely seen in commercial reactor fleets.
Importantly, the RITM-200N design includes protection against natural hazards and man-made threats, including the impact of a commercial aircraft crash.
The safety record is validated by real-world deployments.
For instance, the Akademik Lomonosov floating power unit, located less than a kilometre from the port city of Pevek, has had no impact on local radiation levels. Similarly, the Bilibino plant has safely operated for over four decades just 4.5 km from the nearest town.
How is the fuel cycle handled
Rosatom’s approach to the SMR NPP nuclear fuel cycle is designed for efficiency, long-term autonomy, and non-proliferation compliance — crucial for remote, offshore, or small-grid deployments. The RITM-200N uses high-assay low-enriched uranium (19 per cent enriched HALEU fuel), aligning with international safety and non-proliferation standards.
Each reactor core contains 199 cermet fuel assemblies and is engineered to achieve a refuelling cycle up to six years for land-based SMR NPPs. This reduces the frequency of refuelling and minimises the logistical and safety risks associated with transporting nuclear material, especially critical in isolated regions.
Rosatom draws on its proven nuclear fuel supply chain, which already services its global fleet of large-scale VVER reactors. The company provides partner countries with predictable, safe, and accountable handling of nuclear material throughout the reactor’s lifecycle — from fresh fuel fabrication to spent nuclear fuel utilisation.
Additionally, the fuel used in RITM SMRs is already in use in the KLT-40S reactors aboard the Akademik Lomonosov floating power unit, reinforcing its reliability. The fuel rod cladding is made of a corrosion-resistant alloy, enhancing safety and durability during extended operation and load-following conditions.
How does Rosatom intend to drive the SMR movement?
Rosatom is advancing the global SMR NPP movement through the parallel development and deployment of multiple reactor technologies tailored for remote and off-grid applications.
The Central to this effort is the RITM-200N, currently under construction in the Ust-Kuiga settlement in Yakutia region, is scheduled for commissioning in 2028, to support the development of the Kyuchus gold deposit, one of Russia’s largest. The project is designed to demonstrate the feasibility of SMRs in isolated power systems.
In addition to the land-based initiative, Rosatom is also building four floating power units based on the same RITM-200 technology, further showcasing the reactor’s adaptability across geographies and deployment models.
