The scramble to contain the radiation at the Fukushima Dai-ichi nuclear plant continues, as crews douse its damaged reactors with water from the ground and air while others race to restore much-needed electricity to its cooling pumps.
Crews aboard a pair of Japanese military helicopters began braving the radiation to fly over the nuclear plant Thursday morning local time, dumping sea water on its critically damaged Unit 3 reactor.
Japanese Defence Ministry spokesperson Kazumi Toyama said the water is also aimed at replenishing the spent fuel storage pool that the plant's operator had said was nearly empty.
When exposed, the fuel rods stored in the water overheat and emit more radiation.
In a desperate bid to prevent that from happening, crews flying CH-47 Chinook helicopters worked in 40-minute shifts to limit their exposure. However, strong winds appeared to blow much of the 7,500 litres of water in each run from the target, potentially limiting the dangerous operation's effectiveness.
Meanwhile, at the Unit 4 reactor, there are concerns that water has completely evaporated from the cooling pool for its spent fuel rods.
"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," chief of the U.S. Nuclear Regulatory Commission Gregory Jaczko said at a House Energy and Commerce subcommittee hearing Wednesday.
On Thursday, plant operator Tokyo Electric Power Co. said they believed the rods are still covered, but in subsequent comments Yuichi Sato of Japan's nuclear safety agency edged closer to Jaczko's view.
"Considering the amount of radiation released in the area, the fuel rods are more likely to be exposed than to be covered," Sato said.
In a news conference, top government spokesperson Yukio Edano said special police units have also been called into action. They will use the same high-powered water cannons typically deployed against rioters to try and refill the Unit 3 pool from a safer distance.
Military firefighting vehicles designed to douse burning plane wrecks will also be used.
Power line
Thursday brought one potential piece of good news: the plant's operator said they were close to completing a new power line that could revive the damaged electric cooling systems.
When completed, the line will restore power to the pumps that send a steady supply of water to the six reactors, cooling down any fuel cells.
TEP spokesperson Naoki Tsunoda said officials will test the power line "as soon as possible," but could not say exactly when it would be completed.
The crisis in Japan, sparked by a 9.0-magnitude earthquake that created a monstrous tsunami, prompted a rare address to the nation by 77-year-old Emperor Akihito.
In the televised speech, the emperor urged the Japanese people to give each other hope, despite a horrific death toll expected to exceed 10,000.
"I think it is important for all of us, in various ways and however small, to share the burden of the difficult period that the victims now face," he said.
Japanese police estimate more than 452,000 people have been displaced the quake and ensuing tsunami that struck off the country's northeastern on March 11.
The official number of dead now exceeds 5,300 people, though the toll is expected to rise above 10,000.
Approximately 70,000 have been evacuated from the 20-kilometre exclusion zone surrounding the Dai-ichi plant in Fukushima, while another 140,000 residents of the area between 20- and 30-kilometres from the plant remain under instruction to stay indoors.
The U.S. is calling on any Americans within 80 kilometres of the damaged nuclear facility to either leave or avoid going outside. The Obama administration has also authorized plans to offer voluntary evacuation to family members and dependents of U.S. personnel in the cities of Tokyo, Yokohama and Nagoya.
Japanese officials say they have no plans to expand their exclusion zone around the plant.
With files from The Associated Press
