The No. 3 reactor at Kansai Electric Power Co.'s nuclear power facility reached criticality -- the point in an intensifying nuclear reaction at which it becomes self-sustaining -- Monday after its operations resumed Sunday, ending Japan's 57-day nuclear power break, Yomiuri Shimbun reported Tuesday.
Officials said the facility's next test would be its ability to generate electricity at a 5 percent level. If there is no problem, the operation would enter a control operation that generates power by connecting to the transmission system, raising its output to 100 percent, then be subject to a final government inspection, officials said.
The No.3 reactor at Oi is Japan's first reactor to resume operations after a regular inspection conducted after the crisis at Tokyo Electric Power Co.'s Fukushima No. 1 nuclear facility in March 2011.
No reactors have been active after the No. 3 reactor at Hokkaido Electric Power Co.'s power station in Tomari went offline May 5, Yomiuri Shimbun said.