'Stable, no radioactive impact': Japan halts restart of world’s biggest nuclear plant

Just hours after the process of restarting the world's biggest nuclear power plant, Japan suspended the process Thursday (Jan 22). The reactor however, remained "stable", said the operator, according to news agency AFP. Operations to relaunch a reactor at the Kashiwazaki-Kariwa plant in Niigata province began late Wednesday after permission was granted by the nuclear regulator amid protests from some sections.

"An alarm from the monitoring system... sounded during the reactor startup procedures, and operations are currently suspended," Takashi Kobayashi, a spokesperson for operator Tokyo Electric (TEPCO), told AFP.

He further said that the reactor "is stable and there is no radioactive impact outside". He also added that an investigation has been ordered into the incident an is not sure when the reactor will resume operations.

About the reactor

Kashiwazaki-Kariwa plant located in the northwest of Tokyo is the world's biggest nuclear power plant by potential capacity, although just one reactor of seven was restarted.

Before 2011, nuclear power accounted for nearly 30 per cent of Japan’s electricity, and it planned to get that up to 50 per cent by 2030. As of 2023, nuclear power accounted for just 8.5% of electricity. Now, Japan wants nuclear power to fulfil 20% of its electricity needs by 2040 as it wants to reduce its reliance on fossil fuels, achieve carbon neutrality by 2050.

Japan shut down all 54 of its reactors after Fukushima meltdown in 2011

Japan, which always relied heavily on energy imports, adopted nuclear power early but had to shut down all 54 of its reactors in 2011 after a massive earthquake and tsunami triggered a meltdown at Fukushima, causing one of the worst nuclear disasters in history.

The seventh reactor at the plant is not likely to be brought back on until 2030, while the other five could be decommissioned, leaving the plant with far short of its capacity of 8.2 gigawatts when all seven reactors were operational.

The meltdown in the reactors at Fukushima Daiichi, 220 km northeast of Tokyo, led to radioactive leakage.