Helical Fusion to Begin Power-On Tests at Pilot Reactor in 2027
Helical Fusion will start preliminary power-on tests at its Helix HARUKA pilot reactor in 2027, aiming for a commercial fusion plant as early as the 2040s.
Japanese fusion energy startup Helical Fusion plans to begin preliminary power-on tests at its demonstration reactor in 2027, the company said, marking a step in its effort to lead in commercial nuclear fusion.
The company is building Helix HARUKA, described as Japan's first integrated pilot reactor based on the helical approach to fusion. The facility is intended to show that stable, continuous fusion reactions are feasible.
Fusion works by forcing atoms together at extremely high temperatures to produce heat, the same process that powers the sun. Unlike today's fission reactors, it promises large amounts of clean power with limited radioactive waste. Yet after seven decades of global research, no commercially viable fusion reactor has been achieved.
Helical Fusion said it completed a performance test of a high-temperature superconducting coil in 2025, replicating the magnetic environment inside a fusion device and achieving stable current flow under superconducting conditions — a world first. The result removed a key obstacle to manufacturing and constructing the integrated demonstration reactor.
Construction of the first spiral coil at the National Institute for Fusion Science site in Toki, central Japan, began early this year and is now largely complete, and the company opened the facility to the media.
If the first-stage tests succeed, Helical Fusion plans to install a second coil and other major components, including a liquid-metal wall blanket, before conducting power-on tests of the completed integrated facility around 2030.
The company intends to follow HARUKA with HELIX KANATA, a larger reactor with a net output of 50 MW, designed to demonstrate stable and continuous power generation. Full-scale investment in that project is planned for the 2030s.
Helical Fusion is the only private-sector inheritor of the helical fusion technology developed by NIFS, one of the world's largest fusion research facilities. It aims to develop the first commercially viable fusion power plant based on the helical design.
CEO Takaya Taguchi told reporters the company aims to build a commercial power plant as early as the 2040s, but said various hurdles remain before commercial operations can begin — not only technical ones, but also issues such as cost, safety and construction speed.
Prime Minister Sanae Takaichi is a strong supporter of the fusion industry. The government has designated fusion energy as one of 17 strategic sectors and plans to invest 3.1 trillion yen ($19.7 billion) through public and private funding by the 2040 financial year.