Japan struggles to avert nuclear plant meltdown

illustration photo - source: AFP

Prime Minister Naoto Kan said according to Kyodo News that the Fukushima plant where crews are struggling to control overheating reactors was still at an an "alarming" state.

Tokyo's stock market plunged 5.42 per cent in opening trade as investors absorbed the impact of Friday's earthquake, the biggest in Japan's history, and the devastating tsunami that followed.

The Nikkei index fell to its lowest levels since November, breaching the psychologically important 10,000 barrier, and shares in top automakers tumbled by more than 10 per cent after widespread plant shutdowns.

Aftershocks have continued to shake the country and on Monday morning a strong tremor was felt in Tokyo from what authorities said was an offshore earthquake.

With ports, airports, highways and manufacturing plants shut down, the government has predicted "considerable impact on a wide range of our country's economic activities".

The Bank of Japan injected a record 7 trillion yen ($85.7 billion) into the short-term money market Monday, the largest ever in a single operation by the central bank, as it attempted to build confidence.

"We will take every possible measure, including providing liquidity, to ensure the stability of financial markets and smooth settlements (of business deals)," a bank spokesman said.

The yen gained ground against major currencies in early Asian trade Monday, briefly touching 80.60 against the dollar, its highest level since November 9.

Leading risk analysis firm AIR Worldwide said the quake alone would exact an economic toll estimated at between $14.5 billion and $34.6 billion (10 billion to 25 billion euros), without taking into account the effects of the tsunami.

An explosion at the ageing Fukushima No. 1 atomic plant blew apart the building housing one of its reactors Saturday, after its cooling systems and back-up generators were knocked out by the quake and the tsunami waters.

The atomic emergency escalated as crews struggled to prevent overheating at a second reactor where the cooling system has also failed, and the government warned that it too could suffer a blast.

Kan said in a televised national address Sunday that Japan was facing its worst crisis since the end of World War II -- which left the defeated country in ruins.

"The current situation of the earthquake, tsunami and the nuclear plants is in a way the most severe crisis in the 65 years since World War II," said the premier, who was dressed in an emergency services suit.

"Whether we Japanese can overcome this crisis depends on each of us."

Rolling power outages were due to start later Monday as the quake and tsunami crippled nuclear power plants in the northeast. Japan's nuclear industry provides about a third of its power needs.

Millions of people have already been without electricity since the disaster hit Friday.

Top government spokesman Yukio Edano said Sunday it was highly likely that a partial meltdown had occurred at the plant's number one reactor, and a second was possible at the plant 250 kilometres (160 miles) northeast of Tokyo.

"There is the possibility of an explosion in the number three reactor," he said, while voicing confidence that it would withstand the blast as the first reactor had.

A meltdown occurs when a reactor core overheats and causes damage to the facility, potentially unleashing radiation into the environment.

Edano said that some radiation had escaped in the accident, but that the levels released into the air were so far not high enough to affect human health.

Plant operator Tokyo Electric Power said that despite continuing efforts, it had not managed to ensure that the tops of the fuel rods in the two troubled reactors remained submerged. Exposed rods increase the risk of a meltdown.

France's Institute of Radiation Protection and Nuclear Safety (IRSN) said "very large" amounts of radioactivity were "produced simultaneously with the explosion" at Fukushima.

"During the explosion the rate of release at the edge of the site would have attained one millisievert (mSv) per hour," compared with naturally present radioactivity of 0.0001 mSv per hour, it said Sunday.

At another plant 120 kilometres from Tokyo, the Tokai No. 2, a cooling pump had failed but a back-up was working and cooling the reactor, a plant spokesman said Monday.

The United Nations said a total of 590,000 people had been evacuated in the quake and tsunami disaster, including 210,000 living near the Fukushima nuclear plants.

The colossal 8.9 magnitude tremor sent waves of churning mud and debris racing over towns and farmland in Japan's northeast, destroying everything in its path and reducing swathes of countryside to a swampy wasteland.

The police chief in badly hit Miyagi prefecture said the death toll was certain to exceed 10,000 in his region.

In the Miyahi port town of Minamisanriku alone some 10,000 people were unaccounted for -- more than half the population of the town, which was practically erased, public broadcaster NHK has reported.

The national police agency said the confirmed death toll now stood at 1,597, but groups of hundreds of bodies were being found along the shattered coastline.

Many survivors were left without water, electricity, fuel or enough food, as authorities appeared overwhelmed by the monumental scale of the disaster.

Japan committed 100,000 troops -- about 40 percent of the armed forces -- to spearhead a mammoth rescue and recovery effort with hundreds of ships, aircraft and vehicles headed to the Pacific coast area.

The world rallied behind the disaster-stricken nation, with offers of help even from Japan's traditional rival China.

The US aircraft carrier Ronald Reagan has arrived at the northeast coast, part of a flotilla sent by Japan's close ally. US Navy helicopters were transporting relief supplies for quake and tsunami survivors.

Japan sits on the "Pacific Ring of Fire", and Tokyo is in one of its most dangerous areas, where three continental plates are slowly grinding against each other, building up enormous seismic pressure.

The immense force of Friday's quake has moved Honshu -- the main Japanese island -- by 2.4 metres (eight feet), the US Geological Survey said.

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