TEPCO to Restart Kashiwazaki-Kariwa No. 6 Reactor After Delay

Tokyo Electric Power Company (TEPCO) announced plans to restart its No. 6 reactor at the Kashiwazaki-Kariwa nuclear power plant in Niigata Prefecture, Japan, on Wednesday evening, marking the utility's first such operation since the 2011 Fukushima disaster. The restart, scheduled for 7 p.m. local time, follows a one-day delay caused by an alarm malfunction during pre-operational testing.

The Kashiwazaki-Kariwa facility, the world's largest nuclear power plant with a total capacity of 8.2 gigawatts across seven reactors, has been offline since 2012 amid heightened safety scrutiny. The No. 6 unit, capable of generating 1.36 gigawatts, cleared regulatory safety checks in 2017 but faced additional delays due to concerns over counterterrorism measures. TEPCO resolved the recent issue, which involved an alarm designed to prevent unintended withdrawal of control rods that regulate nuclear fission. During a test on Saturday, the alarm failed to activate when workers attempted to pull out multiple rods from the reactor's core, which contains 872 fuel assemblies and 205 control rods. After correcting a settings error and verifying the system, the company deemed the problem fixed and...