Tokyo Electric Power Company Holdings announced that its No. 6 reactor at the Kashiwazaki-Kariwa nuclear power station in Niigata Prefecture has begun transmitting electricity to the Tokyo metropolitan area for the first time in 14 years. The company conducted a grid connection test early Monday morning and started full-scale transmission in the evening. Commercial operations are scheduled for March 18.
Tokyo Electric Power Company Holdings, Inc. (TEPCO) revealed on February 18, 2026, that the No. 6 reactor at its Kashiwazaki-Kariwa nuclear power station in Niigata Prefecture has started transmitting electricity to the Tokyo metropolitan area, marking the first time in 14 years.
The company conducted a test connecting to the power grid at 2:55 a.m. on Monday, gradually increasing output to 20% or 270,000 kilowatts. Full-scale transmission began at 10 p.m. TEPCO plans to raise the reactor's output by 50%.
Later this month, the firm will halt the reactor to inspect for abnormalities from temperature or pressure changes, then restart it and increase output to full capacity. Commercial operation is expected to start on March 18, pending approval from the Nuclear Regulation Authority. According to TEPCO, the reactor can supply electricity to 3.75 million households if it operates stably for a month.
The No. 6 reactor was restarted on January 21 but halted on January 23 due to an alarm during control rod withdrawal, which regulates the nuclear chain reaction. After identifying the cause and implementing preventive measures, TEPCO restarted it on February 9. A neutron measuring device malfunctioned on February 12 but functioned properly on February 14 after parts replacement.