Tokyo, March 15: Radiation levels spiked Tuesday after blasts and a fire at reactors in a quake-damaged nuclear power plant in northeastern Japan, and a government spokesman said they were high enough to affect human health.
The plant’s operator, the Tokyo Electric Power Co. (TEPCO), said it feared the reactor containment vessel had been damaged in an explosion in reactor number 2 at a plant in Fukushima that is home to six nuclear reactors.
A fire was also reported Tuesday in reactor number 4. TEPCO officials told the broadcaster NHK that an explosion was heard before the fire broke out, and one official was quoted as saying that it was believed to be a hydrogen blast.
Hydrogen explosions rocked reactors 1 and 3 at the plant Saturday and Monday, leading to fears of reactor meltdowns.
The fire at reactor 4 was put out, TEPCO said, but top government spokesman Yukio Edano said Tuesday that radioactivity around the damaged nuclear reactors 250 km north of Tokyo have reached dangerous levels.
“We are talking now about radiation levels that can endanger human health,” the chief cabinet secretary said.
A little more than two hours after the explosion in reactor number 2, radiation had exceeded 8,217 microsievert per hour, more than eight times the allowed annual exposure level, TEPCO said.
In some areas near the power plant, radiation levels rose to 400 millisievert per hour, Edano said. That level is 20 times the allowed annual exposure limits for nuclear industry workers and uranium miners.
TEPCO admitted that a meltdown, a critical nuclear accident in which fuel rods melt and are destroyed, was possible.
TEPCO said it had evacuated workers at the power plant, leaving only about 50 necessary to continue work to try to cool the reactors and prevent meltdowns.
A flight ban was imposed within a 30-km radius of the plant, and Edano told residents living within that zone that they should close their doors and windows and not wear clothing that has hung outside.
People living within 20 km of the facility had been ordered to evacuate at the weekend, and Prime Minister Naoto Kan said Tuesday that most had done so.
The danger decreases the farther one is away from the reactors, Edano said. “We can continue to lead our normal lives,” he said.
Friday’s magnitude-9 earthquake and tsunami caused the cooling systems of reactors at Fukushima to fail, leading to the explosions and fears of reactor meltdowns.
Winds at the time of Tuesday’s problems were blowing to the south, and small amounts of radioactive substances, including caesium and iodine, were later detected in the capital.
The measurements were not enough to present a health risk, the Kyodo News agency said, citing the science ministry.
In Ibaraki prefecture near Fukushima, radiation was measured at 100 times higher than normal while in Kanagawa prefecture south of Tokyo, radiation was 10 times over normal levels, the government said.
Many of the 35 million people living in the Tokyo metropolitan area have left the city for southern Japan for fear of a nuclear accident.
Kan urged the population to remain calm in the face of the escalating crisis at the damaged plant while also warning that further radiation leaks were possible.
A resident of Yokohama, about 270 km south of the Fukushima plant, expressed fears and scepticism about the information being released about the risks.
“Nobody is telling you the truth here,” Michael Paumen, a German business manager, said in a telephone interview.
“Information is too vague and too sparse,” he said, complaining that until Monday afternoon there were no news reports about any nuclear threat.
“They barely mentioned the danger,” Paumen said.
Water was continuing to be pumped into reactors 1, 2 and 3 to try to cool them and it was believed temperatures could be kept down, Edano said.
Buildups of hydrogen were blamed for the explosions in reactors 1 and 3, which blew off the outer shells of the buildings. In contrast, Tuesday’s explosion damaged the reactor itself.
Prior to the latest blast, workers at the plant had been struggling overnight to keep reactor 2’s nuclear fuel rods cool, repeatedly trying to pump seawater into the reactor as the water coolant in the reactor’s core fell below the level of its fuel rods.
Seawater has also been used to cool the cores of reactors 1 and 2, a process that will make the reactors unusable in the future.
Earlier Tuesday, Kan said he would personally lead an integrated headquarters for handling the nuclear crisis, combining both government officials and TEPCO.
Friday’s disaster killed at least 10,000 people, police said.
–IANS