The effort to contain the release of radiation at the stricken Fukushima Daiichi nuclear power station has been stymied because radiation levels at the facility are so high that workers have been unable to successfully deploy police water cannons in a last-ditch effort to cool piles of melting reactor fuel.
In the United States, the head of the Nuclear Regulatory Commission told Congress the U.S. believes that Japanese officials are understating the level of radiation released at the Fukushima complex. NRC Chairman Gregory Jaczko warned any Americans still in Japan to leave an area within a 50-mile radius of the nuclear power plant. Thus far, Japan’s exclusionary zone has been set at a 20-mile radius, with a warning that people living between 20 and 30 miles of the power station should stay indoors and seal their windows and doors.
Two of the six reactors at the Fukushima complex are believed to be in a state of meltdown. Concrete and steel containment vessels encasing the two reactors most likely have been breached, experts say.
Of even greater concern, in terms of the release of high-level radiation are piles of spent reactor fuel rods that are stored in pools located directly under damaged outer containment structures of the reactors at Fukushima. Aerial photos of reactor no. 4 appear to show about 80 tons of smoldering fuel rods exposed directly to the air.
Workers attempting to use police water cannons to spray the spent fuel piles could not get within 50 yards of the reactors due to severe radiation. Radiation also inhibited efforts to use helicopters to dump water on the crippled reactors from the air, as pilots could not fly low enough to hit the target.
Under pressure from the global news media, Japanese officials released information regarding the amount of enrich uranium and plutonium nuclear fuel at the Fukushima complex. Counting fuel rods installed in the six reactors and several piles of spent fuel rods, the total comes to more than 300 tons, nearly twice the amount that was onsite at the Chernobyl nuclear plant when it exploded in 1986.