Published on Monday May 09 2011 (AEST)
ATOMIC power will remain a major part of Japan's energy policy despite the ongoing crisis at one tsunami-crippled plant and a looming shutdown of another while its quake protections are improved.
Deputy chief cabinet secretary Yoshito Sengoku said no reactors other than the three units at the Hamaoka power plant in central Japan would be shuttered over quake and tsunami concerns.
There is "no need to worry" about other reactors, Sengoku said. "Scientifically, that's our conclusion at the moment."
The government evaluated Japan's 54 reactors for quake and tsunami vulnerability after the March 11 disasters that heavily damaged the Fukushima Dai-ichi plant in north-east Japan.
Chubu Electric Power Co., which runs the Hamaoka plant, is still considering the government's request to shut the reactors while the utility builds a seawall and improves back-up systems to protect the reactors from a major earthquake and tsunami.
Nuclear energy provides more than one-third of Japan's electricity, and shutting the three reactors would likely worsen power shortages expected this summer. Already, buildings have reduced lighting, stores have trimmed service hours and subway operators have shut air conditioning in a conservation effort in the capital region since the March 11 disasters.
After an executives' meeting Saturday failed to finalise a decision, Chubu chairman Toshio Mita left for Qatar to negotiate for liquefied natural gas supplies to cover the shortfall, company official Tatsuo Sawaki said.
The three reactors account for more than 10 percent of the company's power supply, company officials said.
Chubu Electric has estimated maximum output of about 30 million kilowatts this summer with the three Hamaoka reactors running, with estimated demand of about 26 million kilowatts.
"It would be tight," said another Chubu official Mikio Inomata, adding that officials are discussing possibilities of boosting output from gas, oil and coal-fuelled power plants and buying power from other utility companies.
The Hamaoka plant is a key power provider in central Japan, including nearby Aichi, home of Toyota Motor Corp.
The plant about 200km west of Tokyo has been known as Japan's "most dangerous" nuclear plant as it sits in an area where a major quake is expected within decades. About 79,800 people live within a 10-km radius.
Prime Minister Naoto Kan noted on Friday that experts estimate a 90 per cent chance of a quake with a magnitude of 8.0 or higher striking that region within 30 years.
"That makes Hamaoka an exceptional case," Kan told reporters on Sunday. He urged Chubu executives "to understand".
Since the March 11 disasters, Chubu Electric has drawn up safety measures that include building a 12-meter seawall nearly 1.5km long over the next two to three years, company officials said. Chubu also promised to install additional emergency backup generators and other equipment and improve the water tightness of the reactor buildings.
The Hamaoka plant lacks a concrete sea barrier now. Sand hills between the ocean and the plant are up to 15 meters high, deemed enough to defend against a tsunami around 8 meters high, officials said.
The operator of the Fukushima nuclear plant, Tokyo Electric Power Co., has said the tsunami that wrecked critical power and cooling systems there was at least 14 meters high.