The operator of Japan’s aging Hamaoka nuclear power plant, located near a tectonic faultline southwest of Tokyo, shut down one of its two running reactors yesterday, officials said.
Japanese Prime Minister Naoto Kan last week called for the closure of the plant, eight weeks after a massive quake and tsunami damaged the Fukushima nuclear plant northeast of Tokyo, sparking the world’s worst atomic crisis in 25 years.
Chubu Electric Power finished inserting control rods inside the No. 4 reactor yesterday afternoon, the final procedure in the operation, the Nagoya-based firm’s spokesman Mikio Inomata said.
“The reactor has come to a halt,” Inomata said.
“There was no problem and everything went as scheduled,” he said, adding that the reactor would soon enter stable “cold shutdown” status.
The firm also planned to begin shutting down the No. 5 reactor today, the spokesman said.
Seismologists have long warned that a major quake is overdue in the Tokai region southwest of Tokyo where the Hamaoka plant is located. It is only 200km from the capital and megacity of Tokyo.
The Hamaoka plant has five reactor units, but only No. 4 and No. 5 were most recently running. Reactors No. 1 and No. 2, built in the 1970s, were stopped in 2009, and No. 3 is currently undergoing maintenance.
The Hamaoka plant accounts for almost 12 percent of the output of Chubu Electric, which serves a large part of Japan’s industrial heartland, including many Toyota auto factories.
Kan said the plant should stay shut while a higher sea wall is built and other measures are taken to guard it against a major quake and tsunami. Local media said the suspension would last about two years.
Japan, the world’s No. 3 economy — a volcanic archipelago that is hit by about 20 percent of major earthquakes around the world — generates about 30 percent of its power from nuclear plants.
The record March tremor and wave that battered Japan’s northeast coast caused 11 of Japan’s 54 nuclear reactors to automatically shut down, while triggering a major crisis at the Fukushima plant.