Originally published September 2, 2013
This animation explains the process by which a pressurized water reactor, such as those at the Oi nuclear power plant, are moderated and shutdown.
The Kansai Electric Power Co. began the shutdown process on its No. 3 reactor at the Oi nucelar power plant, in Japan's Fukui prefecture, on Monday. The shutdown will be complete by Tuesday morning, Japan time, and is required by government regulators in order to conduct scheduled safety inspections once every 13 months. The Oi plant's No. 3 and No. 4 reactors have been Japan's only operating reactors since June of 2012. Before that, Japan's 50 commercial reactors were taken offline in response to the disaster at the Fukushima Daiichi nuclear power plant in March 2011.
The Oi plant's No. 4 reactor will be also shutdown on September 15th for safety inspection. There is strong public opposition to restarting either reactor.
The Oi plant's reactors are pressurized water reactors, among the most common type in the world. They are generally prefered for their small size and self moderating design.
