Japan nuclear crisis drags on but experts hopeful
Workers battled to staunch radiation leaks at a Japanese nuclear plant yesterday, almost two weeks after it was disabled by an earthquake and tsunami, but some experts saw signs of the crisis being brought under control.
Hundreds of workers have been desperately trying to cool down the six reactors and spent fuel ponds at the Fukushima Daiichi plant, 240 km north of Tokyo, since the March 11 disaster, including pumping in seawater or dropping water from the air.
Two of the reactors are now seen as safe in what is called a cold shutdown, but the other four remain volatile, emitting steam and smoke periodically and raising radiation levels in the vicinity.
But that does not mean the situation is out of control, the experts said.
"The reactors are more stable as time progresses," said Peter Hosemann, a nuclear expert at the University of California, Berkeley.
"By now, the decay heat is greatly reduced and it becomes easier to supply sufficient water for cooling. As far as we know, the containments are holding and the radiation levels have dropped."
But he added: "We might see some more release of radioactive material, mostly due to the water going through the systems."
Meanwhile, radioactive iodine dropped back below the level safe for infants in Tokyo drinking water yesterday, an official of the Japanese capital city's government said, confirming media reports.
In one Tokyo ward, Katsushika, a water sample that was taken on Tuesday and publicised on Wednesday had contained more than double the legal limit for infants, at 210 becquerels per kilogramme.
But the level fell back to 79 in a test yuesterday, a Tokyo official told AFP.
The upper limits are 100 becquerels for infants and 300 for older people.
Three workers at the Fukushima Daiichi nuclear plant's reactor number 3 were exposed to high radiation, Japan's nuclear safety agency said yesterday.
Two of the workers were hospitalised "after being exposed to radiation ranging from 170 to 180 milli-sieverts,” NISA spokesman Hideyuki Nishiyama said.
After more than a week, workers managed to connect power to the reactors, but since seawater has been used to cool the plant, checks are needed on all systems before electricity can be switched back on.
Once coolers are switched on, reactor temperatures should fall rapidly and the plant could be on its way to being declared safe, the experts said.
A Japanese nuclear expert said the main risk was from continued radiation leaks was low.