Fukushima: better but not good
Another update has come out from official Japanese sources. They have finally started pumping more seawater into the cores of Units 1, 2 & 3 to raise the water level to cover the fuel rods. Amazingly enough, they have had the levels from 1,300 mm to 2,300 mm below the top of the rods!!! The temperatures have dropped, the oil fire burned itself out and they have regained momentum in gaining control. The radiation has been mostly volatile iodine (gas state), not particulate cesium (fine solid state). The convective force has been too small to loft the cesium, so the principal radiation issue is the iodine, which has a half-life of 8 days. What cesium got out would have been when they vented the reactors and experienced the hydrogen explosions, or when the spent fuel ponds were very low on water. Both have not been an issue for days and are unlikely to recur. So we are past the peak of the radation plume and it will die down by one-half every 8 days. So in two months, it will be less than one percent of what it is now.
Thomas Lifson adds:
A new estimate of radioactive material stemming from Japan's damaged Fukushima Daiichi nuclear complex suggests airborne levels may be higher than what's allowed for infants well outside the plant's 12-mile evacuation zone, shedding new light on an international debate over how close is too close to the center of the nation's nuclear crisis.
Mr. Edano said three workers had been injured just after noon at Unit No. 3, suffering radiation burns on their legs, while dragging an electrical cable through contaminated water. They were exposed to more than 170 millisieverts of radiation, he said, and two were taken to Fukushima Medical University Hospital and were expected to be transferred to the National Institute of Radiological Science in Chiba City, east of Tokyo.