Japan quake-hit plant may be shut a year or more

TOKYO, July 19 (Reuters) The world's biggest nuclear power plant may be shut for more than a year for safety checks after an earthquake in Japan caused radiation leaks, prompting speculation of power shortages and prompting a run on the firm's shares.

Fears about the safety of Japan's nuclear industry have been renewed by radiation leaks from Tokyo Electric Power Co's (TEPCO) plant in the northwestern city of Kashiwazaki, hard hit by a 6.8 magnitude quake on Monday.

The trade minster and a local mayor have already said the Kashiwazaki-Kariwa plant, closed since the quake that flattened homes and killed 10 people, cannot reopen until safety is assured.

Today, the Nikkei business newspaper said the government might order TEPCO to keep the plant shut for more than a year while a safety study is conducted.

Japanese media said this raised questions about possible power cuts as the peak summer demand season approached.

TEPCO shares fell more than five per cent today, doubling their loss since the quake hit the plant, which has long been claimed by activists to be unsafe.

Analysts warn the firm, Japan's largest utility, faces millions of dollars in extra costs and a possible dividend cut as it fires up mothballed plants to meet heavy summer demand.

LENGTHY SHUTDOWN? If the earthquake study shows the facility, built over what has turned out to be an active fault-line, needs to be reinforced, it might take much longer than a year before operations can resume, the Nikkei said.

Japan's nuclear regulator, the Nuclear and Industrial Safety Agency, declined to say when the plant might reopen.

''We're not at a stage to discuss a resumption,'' said Hisanori Nei, director of the nuclear power inspection division.

TEPCO spokesman Jun Oshima said the utility was also unsure when it could restart the plant. ''The priority is on being able to say that the facility is safe,'' he said.

The quake-hit facility has a capacity of 8.2 million kilowatts, making up almost half of TEPCO's nuclear generation.

TEPCO has said Monday's quake was stronger than the tremors that the plant, whose first reactor came on stream more than 20 years ago, had been designed to withstand.

International Atomic Energy Agency chief Mohamed ElBaradei has said that the firm had misjudged the seismic risks.

TEPCO said it assumed the fault that caused this week's tremor was one found during research in 1979-1980, as the plant was being built. The fault had not caused concern then because it had not been expected to cause a big quake.

Japan accounts for about 20 per cent of the world's earthquakes of magnitude 6 or greater, and every year there are up to 2,000 quakes that can be felt by people.

TARNISHED INDUSTRY Japan's nuclear industry has been tarnished by cover-ups of accidents and fudged safety records, and the ongoing flow of bad news this week has done nothing to ease concerns.

TEPCO first said there had been no radiation leaks from the quake, which caused a small fire, but later revealed that 1,200 litres (317 US gallons) of radioactive water had leaked into the ocean.

On Tuesday, it said there had been about 50 problems, including a minor radiation leak into the atmosphere.

A day later, the utility revised up the amount of radiation in the leaked water, but added that the amounts were still too small to harm people or the environment.

Tadao Yabe, a local Kashiwazaki lawmaker, said the latest developments would boost anti-nuclear opposition among residents.

''I think people are really fed up. When they saw flames rising from that fire, they must have said, 'that's it','' Yabe told Reuters this week.

Quake-proofing regulations for Japan's 17 nuclear power stations -- which supply about one-third of the resource-poor country's electricity -- were tightened last year, requiring utilities to reassess risks to their plants.

Anti-nuclear activists have charged for decades that the Kashiwazaki-Kariwa plant was unsafe.

In 2005, the Tokyo High Court rejected a demand by residents that a 1977 permit to build the first reactor at the plant be revoked because a safety review had been insufficient and there was an active fault nearby.

TEPCO has asked six utilities for electricity to help replace lost production. It said power supplies were sufficient for now, especially since the summer has so far been unseasonably cool, but added it might restart unused thermal plants if needed.

REUTERS GT RAI1315