Kashiwazaki-Kariwa Unit 6 resumes commercial operation after 14+ years offline

TEPCO (Tokyo Electric Power Company)/Kashiwazaki-Kariwa Restart

Kashiwazaki-Kariwa Unit 6, a 1,315 MW Advanced Boiling Water Reactor, resumed commercial operation on April 16, 2026, after 14+ years offline. This is TEPCO's first reactor restart since Fukushima and Japan's largest by capacity. The unit underwent post-Fukushima safety upgrades to meet NRA requirements. TEPCO plans to operate it for one year until the next inspection in April 2027.

• Kashiwazaki-Kariwa has seven reactors with 7.965 GW combined net capacity, the world's largest nuclear plant.
• Unit 6 is TEPCO's first reactor restart since the 2011 Fukushima Daiichi disaster.
• The January 2026 restart attempt was suspended due to a control rod alarm malfunction. After repairs, Unit 6 returned to commercial operation in April.
• Japan has now restarted 15 nuclear units since 2011, though many reactors remain offline awaiting regulatory approval.