A Japanese military helicopter flew toward a radiation-leaking nuclear plant Wednesday afternoon, a bucket of seawater dangling beneath it, the latest desperate attempt to cool overheated materials that are emitting potentially lethal radioactive steam.
But the operation was deemed too dangerous and aborted, because of high radiation levels in the air above the Fukushima Daiichi plant. Officials were left to find another way to address the explosions and leaks at the stricken facility, which have stoked fear and panic across the nation.
Television cameras first spotted plumes of white steam emitting from unit 3 Wednesday morning, hours after an explosion at unit 2 seems to have breached the main protective shield around the reactor’s uranium-filled core.
Chief Cabinet Secretary Yukio Edano said officials were trying to determine the source of the steam coming from unit 3, and presumed it to be radioactive.
As radiation levels rose, the lone 50 workers charged with cooling efforts were temporarily relocated. Hundreds of other workers had been evacuated Tuesday because conditions were deemed so dangerous.
Within an hour, though, the radiation levels dropped again, and the small group was permitted to return. In order for them to resume trying to cool the damaged sectors, Japan’s Health and Welfare minister had to waive the nation’s standard of radiation exposure, increasing the level of acceptable exposure from 100 millisieverts to 250 — five times the level allowed in the United States.
Wednesday afternoon, the military dispatched two helicopters from Kasuminome Air Base in Sendai. A lead chopper flew to the plant, less than 150 miles north of Tokyo, to determine whether radiation levels were low enough to continue with the operation.
The second helicopter, a Boeing CH-47 was scheduled to make several passes to drop seawater onto unit 3, where an explosion on Monday resulted in structural damage that appears to have compromised the reactor. But the crew on the lead chopper found radiation levels were too high to carry out the risky mission.
The rising steam from the breached sector was just the latest problem for the embattled plant, which suffered heavy damage to its cooling systems after Friday’s devastating earthquake and tsunami. Since, the Japanese government and Tokyo Electric Power Co, which owns the facility, have struggled mightily to keep the plant’s six reactors cool. Each day has brought new problems.
Tuesday’s blast at unit 2 was not outwardly visible, but was potentially more dangerous than some of the earlier explosions, because it may have created an escape route for radioactive material bottled up inside the thick steel-and-concrete reactor tube.
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