2 Juillet 2012
July 2, 2012
FUKUI -- The No. 3 reactor at the Oi Nuclear Power Plant in Fukui Prefecture attained criticality, or a self-sustaining nuclear fission chain reaction, at 6 a.m. on July 2.
The nuclear plant operated by Kansai Electric Power Co. (KEPCO) is the first in Japan to restart after mandatory inspections and regular checkups following the nuclear disaster at the Fukushima No. 1 nuclear plant.
KEPCO will accelerate the 1.18-million kilowatt reactor's heat output while checking the movement of the turbines. If everything goes as planned, the reactor will start generating electricity July 4 before becoming fully operational July 8.
Plant workers reactivated the reactor at 9 p.m. on July 1. They then pulled out the reactor's 53 control rods that prevent nuclear fission and lowered the concentration of boric acid before it reached criticality.
Once the reactor's heat output reaches around a dozen percent, workers will pump vapor into the generator turbine before starting electricity transmission. If the reactor operates without a hitch for about a month , the Nuclear and Industrial Safety Agency will give the go-ahead for resumption of commercial operations.
Meanwhile, demonstrators at the Oi plant, some of whom had blocked the road to the plant, ended their anti-nuclear rally and left the area in the wee hours of July 2.
FUKUI, Japan (Kyodo) -- A reactor at the Oi nuclear power plant in western Japan became late Sunday the first in the country to be reactivated after regular checks since last year's Fukushima nuclear crisis, bringing an end to the halt since early May of Japan's nuclear reactors and easing power constraints.
In reactivating the reactor, the plant's operator, Kansai Electric Power Co., pulled out control rods from around 9 p.m. that have contained fission reactions at the No. 3 reactor at the plant in Fukui Prefecture on the Sea of Japan coast.
The utility is aiming to attain a sustained nuclear fission chain reaction, known as criticality, early Monday, begin power transmission Wednesday, and bring the reactor to full operation possibly on July 8.
Although a growing group of protesters had blocked a road leading to the plant since Saturday, preventing workers' access, officials of the utility serving western Japan said the protest had no impact on Sunday's reactivation as it had already secured sufficient workers.
Meanwhile, local police started Sunday evening to forcibly remove the protesters for alleged trespass on the plant's premises.
Senior Vice Minister of Economy, Trade and Industry Seishu Makino arrived at the site Sunday evening to witness the reactivation as part of the government's efforts to enhance monitoring of the plant's resumption amid public concern over nuclear safety in the wake of the meltdown of three reactors at Tokyo Electric Power Co.'s Fukushima Daiichi plant in northeastern Japan.
Makino had to use a boat to enter the plant from the sea because the road was blocked by the protesters.
"I've watched it with a tense feeling. The government was able to take a necessary step forward amid a controversy that split the nation," Makino told reporters after monitoring the reactivation.
In Tokyo, more than a thousand people rallied in front of JR Shinjuku Station and Shinjuku Central Park to protest at the restart of the reactor.
Once the 1.18 million kilowatt reactor runs at full capacity, the utility will likely see its projected power shortfall for this summer drop to 9.2 percent from 14.9 percent and the government will lower its summer power-saving target for the utility's service area to 10 percent from 15 percent.
Following government approval on June 16, the utility is also preparing to restart the plant's No. 4 reactor to return it to full operation possibly as early as July 17.
Since mid-April, when Prime Minister Yoshihiko Noda and related ministers confirmed the safety of the Oi reactors, the government had been seeking approval for the reactors' restart from Fukui Prefecture and the coastal town of Oi where the plant is located.
After recognizing power shortages were likely to occur this summer, governors and mayors in western Japan backed off from their earlier opposition in late May, and the Union of Kansai Governments effectively gave consent for the reactivation.
Since the last operating reactor in Hokkaido was deactivated for routine checks in early May, all of Japan's 50 operational commercial reactors had been idled amid heightened public concern over the safety of nuclear power following the Fukushima disaster, triggered by the March 2011 earthquake and tsunami.