Gordon Rayner and Martin Evans – Telegraph.co.uk March 14, 2011
The Japanese nuclear safety agency says explosion heard at Unit 2 of Fukushima Daiichi plant.
Earlier a cloud of radioactive dust billowed from the Fukushima Daiichi power plant after it suffered its second explosion in three days.
Government officials admitted that it was “highly likely” the fuel rods in three separate reactors had started to melt despite repeated efforts to cool them with sea water. Safety officials said they could not rule out a full meltdown as workers struggled to keep temperatures under control in the cores of the reactors.
The Fukushima crisis now rates as a more serious accident than the partial meltdown at Three Mile Island in the US in 1979, and is second only to the 1986 Chernobyl disaster, according to the French nuclear safety authority. After insisting for three days that the situation was under control, Japan urgently appealed to US and UN nuclear experts for technical help on preventing white-hot fuel rods melting.
The International Atomic Energy Agency (IAEA) said it was “unlikely” that the accident would turn into another Chernobyl, but failed to rule it out completely.
More than 500,000 people are thought to have been made homeless by Friday’s earthquake and tsunami, which is estimated to have killed at least 10,000. More than 2,000 bodies have been washed up on beaches along Japan’s Pacific coast, but rescuers have yet to reach isolated towns and villages in some of the worst-affected areas.
The tragedy is expected to become the costliest natural disaster in history, with the repair bill likely to top £100 billion.
The economic impact was already being felt around the world yesterday as a 6.2 per cent fall in the Nikkei share
index triggered significant losses on stock markets elsewhere. In London, the FTSE-100 fell by almost one per cent over the course of the day, wiping £15 billion off the value of shares.
David Cameron said there were “severe concerns” for a number of Britons living in the disaster zone who have still not been in touch with their families. The Foreign Office said its emergency helpline had received 4,700 calls from people worried about relations, but had no confirmed reports of British casualties.
Fears of a meltdown at the Fukushima Daiichi power station, 150 miles north of Tokyo, grew significantly after yesterday morning’s explosion at its No 3 reactor. The blast injured 11 workers and released as much radiation in an hour as would normally be expected in six months. It exposed up to 160 people to high doses, and 22 received treatment for radiation poisoning.
Like the explosion in the No 1 reactor on Saturday, the problem was caused by a build-up of hydrogen released from water surrounding the reactor as temperatures rose above 2,200C.
The aircraft carrier USS Ronald Reagan later detected increased radiation 100 miles off the coast of Japan and weather forecasters said that the wind direction would change overnight, blowing the radioactive cloud inland. Scientists said it did not pose a health risk.
Seventeen US helicopter crewmen helping with the relief effort were exposed to levels equivalent to one month’s normal background radiation, but were declared free of contamination after being scrubbed down.
As technicians tried to contain the temperatures inside all three reactors at the plant, there were warnings of a possible third explosion as fuel rods inside the No 2 reactor became fully exposed.
Workers managed to pump enough seawater into the reactor to cover the rods, but they became partly exposed last night. Ryohei Shiomi, an official at Japan’s Nuclear and Industrial Safety Agency, said the rods in all three reactors appeared to be melting.
“Units one and three are at least somewhat stabilised for the time being,” he said. “Unit two now requires all our effort and attention.”
Yukio Edano, the chief cabinet secretary, said it was “highly likely” that the fuel rods were melting.
In the event of a complete meltdown, where the uranium core melts through the outer containment shell, high levels of radiation would be released into the environment, a major risk to health.
Andre-Claude Lacoste, head of the nuclear safety authority in France, the world’s second-largest producer of nuclear power, said the accident was now “worse than Three Mile Island but not as great as Chernobyl”. The partial meltdown in Pennsylvania in 1979 was rated five out of seven on an international scale, with Chernobyl put at seven.
While Japan’s nuclear safety agency rates Fukushima as level four, Mr Lacoste said: “We have the feeling that we are at least more than level five and probably at level six. I say this after speaking to my Japanese counterparts.”
Yukiya Amano, director general of the IAEA, said it was “very unlikely” to turn into an accident similar to Chernobyl as “the design is different and the structure is different”, making the reactors far safer. But local residents remained distrustful of official assurances, following accusations of cover-ups in the past.
Kyoko Nambu, whose home was destroyed by the tsunami, said: “It’s like a horror movie. Our house is gone and now they are telling us to stay indoors.
“We can see the damage to our houses, but radiation? We have no idea what is happening. I am so scared.”
Around the world, Germany and Switzerland reacted by suspending plans for new reactors. Italy and Poland said they would rethink plans to invest in nuclear energy, and Friends of the Earth urged the British government to scrap its own plans for new reactors.
Andy Atkins, the campaign group’s executive director, said: “We can’t keep heading down the nuclear route until the lessons from this crisis have been learnt.”