The reactor, which began operations in late October, was temporarily halted earlier this month after a checking device became stuck inside the containment vessel. The issue was traced to a loose nut on a guide tube, which was replaced in May.

The restart of the Onagawa reactor marks a significant milestone in Japan's nuclear power industry, particularly in the regions affected by the 2011 earthquake and tsunami. The plant has undergone rigorous safety inspections and upgrades to meet stricter standards implemented after the Fukushima Daiichi nuclear disaster.

The operator, Tohoku Electric Power Co., aims to begin commercial operations of the reactor around December. (ILKHA)