US, June 08 : A privately developed American nuclear reactor has achieved first criticality, marking a significant milestone in the United States’ push to revive advanced atomic energy technologies and expand their global deployment, including in India.
The Mark-0 demonstration unit, built by Antares Nuclear, successfully initiated a self-sustaining chain reaction on June 4, reaching the milestone ahead of schedule. The achievement is being viewed as a major step toward commercial deployment of compact nuclear systems capable of serving remote communities, industrial facilities and strategic infrastructure.
Industry leaders have described the development as evidence of a renewed American commitment to nuclear innovation after decades of limited progress in reactor technology.
According to Maria Korsnick, President and Chief Executive Officer of the Nuclear Energy Institute, India represents a key market for emerging reactor designs alongside large scale projects such as AP-1000 units. She said advanced nuclear systems can provide flexible solutions tailored to different energy requirements.
Unlike conventional power plants, micro-reactors are designed to generate electricity ranging from a few hundred kilowatts to around 1.2 megawatts. Their compact size allows transportation by air and rapid deployment in isolated locations. The technology is also being examined for future space applications.
The Antares project is the first of three advanced reactor demonstrations expected to showcase new capabilities before the United States celebrates the 250th anniversary of its independence next month. Additional designs under development include Westinghouse’s eVinci and Radiant’s Kaleidos systems.
US Energy Secretary Chris Wright hailed the achievement as a landmark moment for the country’s nuclear sector, saying it reflects growing momentum behind advanced reactor programmes.
The push has been supported by policy changes aimed at accelerating innovation. Recent executive actions streamlined approval pathways for advanced reactor projects and expanded the Department of Energy’s role in supporting new technologies.
Korsnick noted that the rise of inexpensive natural gas following the shale revolution slowed investment in atomic energy for decades. However, growing electricity demand and advances in reactor design are once again driving interest in the sector.
Modern systems are being developed with a variety of cooling technologies, including water, molten salt and gas. Beyond electricity generation, these reactors can support industrial processes requiring high-temperature steam and may also be used for hydrogen production.
India is simultaneously pursuing an ambitious expansion of its own nuclear programme. The country aims to raise installed nuclear capacity from about 9 GW to 100 GW by 2047, relying on both large plants and compact reactors for energy intensive industries.
To support that goal, Indian researchers are developing multiple indigenous designs, including the 200 MWe Bharat Small Modular Reactor, a 55 MWe unit and a high temperature gas cooled reactor intended for hydrogen generation. Recent policy reforms have also opened greater opportunities for private sector participation in the country’s atomic energy ecosystem.