Electricity generated from nuclear fission began flowing in Japan on Thursday, ending a nearly two-month hiatus in the aftermath of the Fukushima meltdowns, the operator said.
Engineers working at Unit No. 3 at Oi power plant in western Japan connected up its turbine allowing it to begin generating power around 7:00 am (2200 GMT Wednesday), a spokesman for Kansai Electric Power Co. (KEPCO) said.
Its initial 50,000 kilowatts output will gradually increase to a 1.18 million kilowatts capacity as early as Monday, he said.
Following government approval on June 16, the unit was restarted on Sunday, achieving a self-sustaining fission reaction -- criticality -- on Monday.
The resumption of the reactor is expected to ease KEPCO's expected power shortfall for this summer and lead the government to lower its summer power-saving target for the firm's service area in western Japan to 10 percent from 15 percent.
The government has asked households and businesses served by six utilities in central and western Japan to voluntarily cut consumption of electricity by between five and 15 percent on summer 2010 levels through to September 7.
Power consumption usually rises in the summer as people turn on air conditioners to cope with the sometimes sweltering weather.
Japan had been operating without nuclear power since early May when the last of its 50 working reactors was shut down for a scheduled safety check.
Restarts were put on hold as the government mulled its options following a 9.0-magnitude earthquake and tsunami last year that crippled reactor cooling systems at Fukushima, amid predictions more giant quakes would strike Japan.
But on June 16 Prime Minister Yoshihiko Noda gave the green light to restart two reactors at the Oi plant, with warnings the industrial heartland of western Japan could be as much as a fifth short of electricity.
Prior to the disaster at Fukushima, nuclear power had supplied a third of Japan's electricity needs.