Tokyo: The operator of Japan`s ageing Hamaoka nuclear power plant, located near a tectonic faultline southwest of Tokyo, shut down one of its two running reactors on Friday, officials said.
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 number four reactor on Friday afternoon, the final procedure in the operation, said Mikio Inomata, a spokesman with the Nagoya-based firm.
"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 number five reactor on Saturday, 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 200 kilometres (125 miles) from the capital and megacity of Tokyo.
The Hamaoka plant has five reactor units, but only two were most recently running -- numbers four and five. Reactors one and two, built in the 1970s, were stopped in 2009, and three is undergoing maintenance.
The Hamaoka plant accounts for almost 12 percent of the output of Chubu Electric, which services 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 number three 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.