Tokyo, March 17: A Japanese military helicopter has dumped water from a huge bucket onto the stricken Fukushima nuclear power plant, television images show.
Public broadcaster NHK reports there are plans to send more helicopters to douse the plant site.
As Tokyo resorted to increasingly desperate measures to cool overheated reactors at the stricken Fukushima No.1 plant, the embattled Japanese company that operates the facility said today its main priority was to restore power at the complex.
“We cannot tell when, but we want to restore the power source as soon as possible,” a Tokyo Electric Power Co (TEPCO) spokesperson said.
Construction may start as soon as today on a new power line to connect to the Fukushima plant’s water pumps so that workers will be able to cool fuel rods by sending seawater into reactor pressure vessels, containment vessels and storage pools of spent fuel, Nikkei reported.
The power system – and its emergency diesel-fueled generators – failed when a tsunami with waves as large as 24 feet (7.3m) hit the complex, soaking electrical equipment in water, about an hour after a 9.0-magnitude earthquake rocked Japan.
Since then, overheating has caused four hydrogen explosions and two fires at the plant as well as a partial meltdown at the No.1, No.2 and No.3 reactors of the six-reactor facility, located about 155 miles (250km) north-east of Tokyo.
“Damage to the cores of the three units – units 1, 2 and 3 – has been confirmed. The cores remain uncovered by one or two metres,” International Atomic Energy Agency (IAEA) head Yukiya Amano said today.
Amano, who will travel to Japan as early as today, said Japanese authorities had also reported concerns about the spent nuclear fuel pools of reactors No.3 and No.4.
Shortly after, US Nuclear Regulatory Commission (NRC) chairman Gregory Jaczko told Congress that the fuel pool at reactor No.4 had run dry, resulting in “extremely high” radiation levels.
“What we believe at this time is there has been a hydrogen explosion in this unit due to an uncovering of the fuel in the spent fuel pool,” he said, noting the explosion happened several days ago but its effects were cause for concern.
“We believe that secondary containment has been destroyed and there is no water in the spent fuel pool and we believe that radiation levels are extremely high which could possibly impact the ability to take corrective measures.”
The deep pools contain used fuel rods which are extremely radioactive and normally kept immersed in cooling water. Unlike the fuel rods that are used in the reactor vessel, the spent rods are not surrounded by a steel-and-concrete containment vessel. If water in the tanks evaporated, the spent rods would be exposed to the air and radioactive material would be released into the atmosphere.
The IAEA said that temperatures in spent fuel pools are typically kept below 77 degrees Fahrenheit (25C), but by yesterday, the temperature in the No.4 reactor’s tank had risen to 183F (84C). Data was not available for today’s temperature.
Temperatures in the spent fuel pools at the No.5 and No.6 reactors, which also had not been operating at the time of the twin disasters, had reached at least 140F (60C) by yesterday, the IAEA said.
Yesterday, following the cancellation of a helicopter mission to pour water on No.3 reactor due to high radiation levels, a water cannon normally used by riot police arrived at the plant to pump water into the spent fuel pool of No. 4 reactor. Japanese officials planned to use the cannon today.
The US military said it had delivered high-pressure water pumps to Japan to help with the operation at Fukushima and, according to Kyodo News, the military was also set to fly one of its drones equipped with infrared sensors over the plant to take pictures so that experts might assess damage.
US soldiers – and now citizens – are not allowed within 50 miles (80km) of the complex based on guidelines issued by the US Nuclear Regulatory Commission (NRC). The Pentagon also confirmed some military flight crews were issued with potassium iodide tablets to combat the possible effects of radiation.
The Japanese government has thus far only imposed a 12.4-mile (20km) evacuation zone, outside of which Japan’s Chief Cabinet Secretary Yukio Edano said radiation levels posed no immediate health threat.
Meanwhile, panic spread on the ground as millions have been left without water, electricity, fuel or enough food. Hundreds of thousands more were left homeless by the devastation and were dealing with freezing cold and wet weather in the northeast region of Japan.
Around 80,000 of Japan’s Self-Defence Forces personnel, police officers and firefighters have mobilised to assist in relief efforts, as the death toll rose over 4300, with about 8000 more still unaccounted for across the nation, Kyodo News reported.
Expatriates and foreigners have been leaving Japan amid the crises – some with encouragement from their employers and embassies. Australia, France, Germany, the UK and other nations have told their citizens to consider leaving the greater Tokyo area, while companies such as BMW and Ikea have helped evacuate their employees out of the capital to either their homelands or to other parts of Japan.
——–Agencies