A TEPCO worker explains the situation at the stricken Fukushima Daiichi nuclear plant, February 28, 2012.
Japan ends nuclear freeze
03:07 - Source: CNN

Story highlights

NEW: The KEPCO power company starts bringing the Ohi plant back online

"Opposition to restart!" protesters chant outside the plant

All 50 of Japan's commercial reactors have been offline since May for safety tests

The reactors have been stress-tested in the wake of last year's Fukushima disaster

Tokyo CNN  — 

Japan restarted nuclear power production Sunday for the first time since shutting down all the country’s reactors in the wake of the Fukushima Daiichi meltdown after last year’s devastating tsunami.

Kansai Electric Power Co. Ltd. (KEPCO) began an operation to restart the Ohi nuclear plant’s No. 3 reactor on Sunday night, it said, despite protests from raucous demonstrators at the site.

Dancing, chanting, and singing , throngs of demonstrators had converged outside the nuclear power plant earlier on Sunday, decrying the scheduled relaunch.

A line of shield-wielding police contained the protesters outside Ohi, where demonstrators chanted: “Opposition to restart!”

The process of starting a nuclear reactor takes hours, starting with the removal of control rods to allow a chain reaction to begin.

The reactor is due to start providing some electricity to western Japan – which includes Osaka, Japan’s second-biggest city – by Wednesday. Ohi’s No. 4 reactor is scheduled to resume operations by July 24.

All 50 commercial nuclear reactors in Japan have been offline since May 5 for safety checks. The government has been conducting simulation tests for restarting its nuclear reactors in response to public concerns over their safety in the wake of the crisis at the Fukushima Daiichi nuclear plant last spring.

Before the March 11 disaster, Japan had relied on nuclear energy for about 30% of its electricity needs, according to government figures.

Though no deaths have been attributed to the nuclear accident, the earthquake and tsunami killed more than 15,000 people in northeastern Japan. The damaged Fukushima spewed radiation, prompting the government to evacuate tens of thousands of people.

CNN’s Elizabeth Joseph contributed to this report.