Japan will suspend operations at a nuclear reactor in the country’s northeast around Saturday after detecting a leak of water containing a small amount of radioactive material, the plant’s operator said Thursday.
Tohoku Electric Power Co. said the No. 2 reactor at the Onagawa nuclear power plant in Miyagi Prefecture would be shut down to inspect and replace faulty components, according to Kyodo News.
The company said a small amount of radioactive material was detected in the leaking water, but all contaminated water had been collected.
No abnormal radiation levels were detected in the surrounding environment, it added.
The operator estimated that approximately 0.2 metric tons of water had been leaking every hour.
Water levels in a drainage sump had been rising since July, prompting an investigation that identified a leaking valve.
The company said inspections, repairs and preparations for restarting the reactor would take approximately 10 days.
The Onagawa reactor became the first in eastern Japan to resume operations after the devastating 2011 earthquake and tsunami triggered the Fukushima nuclear disaster.
The reactor was briefly shut down in November 2024, just days after restarting, because of equipment problems. It resumed operations later that month following repairs.
The 2011 disaster forced Japan to suspend nuclear operations nationwide and introduce stricter safety requirements before allowing reactors to restart.