Japan is set to reactivate the Kashiwazaki-Kariwa nuclear power plant, widely regarded as the world’s largest by installed capacity, with a potential output of 8.2 gigawatts across its seven units.
This follows a brief suspension caused by an alarm malfunction during the plant’s first restart efforts in nearly 15 years, since the 2011 Fukushima disaster.
Managed by Tokyo Electric Power Company (TEPCO), the plant initially brought its No. 6 reactor, boasting a capacity of 1,360 megawatts, online on January 21, 2026.
Operations were halted about 29 hours later when an alarm indicated a perceived issue in the power system controlling the movement of the reactor’s control rods, though no actual equipment failure occurred.
TEPCO explained that the suspension resulted from a configuration error in the alarm system, which had detected minor but safe fluctuations in electrical current in one cable. Engineers subsequently adjusted the settings after confirming that the reactor remained fully operational and secure.
Speaking at a press conference in Niigata Prefecture, where the coastal facility is located, Takeyuki Inagaki, the plant’s head, announced that the company plans “to start up the reactor on February 9.”
He emphasized that the alarm settings had been modified and verified, assuring that “the reactor is safe to operate,” with commercial operations now scheduled to commence on or after March 18 following additional inspections.
The restart addresses growing energy needs by boosting power supply to the Tokyo region and marks TEPCO’s first reactor reactivation since the Fukushima catastrophe, which led to a nationwide nuclear shutdown.
While only the No. 6 unit is resuming activity for now, plans for the remaining units—including Unit 7, targeted around 2030—are proceeding cautiously amid ongoing safety reviews.
Despite these measures, public unease over nuclear safety persists, heightened by Japan’s vulnerability to earthquakes and tsunamis. Local communities in Niigata continue to voice concerns about potential hazards, even as the government seeks to enhance energy security and reduce reliance on imported fossil fuels through a measured return to nuclear power.
