The World’s Largest Nuclear Power Plant Is a Beast With 7 Reactors. It’s Ready to Come Back Online

Japan's Kashiwazaki-Kariwa plant—located in Niigata, northwest of Tokyo—is a giant many times over. For one, it's the world’s largest nuclear power plant in terms of installed capacity. Secondly, it's operated by the Tokyo Electric Power Company, or TEPCO, the world's third largest electricity company. Then, there's its energy capacity. Armed with seven boiling water reactors, the Kashiwazaki-Kariwa plant can generate more than 8,200 MWe of electricity.

However, the plant’s reputation was tarnished after the catastrophic Fukushima nuclear accident in 2011. Despite its critical role in Japan’s electricity infrastructure, safety was of utmost importance. As such, the Japanese Nuclear Regulation Authority decided to revoke the Kashiwazaki-Kariwa plant's operating license following the incident. To reopen, Japanese authorities required TEPCO to implement new safety measures at the facility that took into account what the company had learned from the 2011 catastrophe.

Japan Is Slowly Coming to Terms With Nuclear Power

Japan currently operates 12 nuclear reactors, with two more under construction. It has 27 reactors that are out of service. Those numbers, however, could soon change. In April 2023, the Japanese government passed new nuclear power legislation that allows plants to continue operating beyond the current 60-year limit. In practice, this means that if a nuclear power plant can operate safely for more than six decades, regulators now allow it to do so.

This new legislation is good news for the Kashiwazaki-Kariwa plant. Japanese nuclear authorities implemented an operational ban on the plant in March 2011 shortly after the Fukushima Daiichi nuclear power plant accident. Late last year, the Nuclear Regulation Authority lifted the ban.

This milestone is the first step towards restoring the plant's operating license. The NRA decided to remove the ban after inspecting the nuclear plant facilities for more than 4,000 hours. The administrative body also confirmed that TEPCO had made the necessary improvements in safety measures and protocols to restart the plant’s operations.

After the NRA’s green light, the ball is now in the Niigata regional government’s court, which needs to approve the nuclear power plant’s facilities before it can regain its operating license. It's unlikely that the Niigata government would present any objections to restarting activity at the Kashiwazaki-Kariwa plant.

TEPCO has already requested permission from the Nuclear Regulation Authority to start inserting fuel rods into the reactors to speed up the process of resuming operations. As such, it’s highly likely that the Kashiwazaki-Kariwa plant, considered the most ambitious nuclear power plant in the world, will be back in operation soon.

Image | IAEA