As a result of the catastrophic tsunami that just hit Japan, 5 nuclear power plants are now in emergency mode, and it's reported that US military have flown in to help. An Al Jazeera analyst says the engineers are struggling valiantly, but not doing a very good job, thus far, having been compelled to vent contaminating radioactive gases into the atmosphere to prevent a blowout.
Sun Times
A real threat is posed of potential meltdown(s), projected to be worse than Chernobyl, should the worst case scenario ensue. While this is a completely different kind of Nuclear plant, evidently the large quantitiy of fuel in these reactors could make a very nasty dirty bomb.
As pressure rises to 1.5x normal within the primary containment dome, in order to prevent a complete blowout, they have begun venting radioactive steam into the atmosphere, which it is acknowledged will spread some local contamination, but 1000x less than would be released if there is a blowout.
A blowout would allow all of the coolant water to boil out, which would cause temperature and radiation to rise drastically, causing the fuel to melt and explode, spreading radioactive contamination on a very large, wide scale, even worse than what happened at Chernobyl, potentially.
Radiations Leaks Detected
The previously ordered Fukushima evacuation perimeter has been expanded to over 10 miles, as thousands of people flee.
Evidently, when power went down, they ran out of backup batteries, which stopped the cooling system pumps. Replacement batteries were flown in by helicopter, other access being blocked by tsunami wreckage.
They have recently also brought in backup power generators to replace those damaged by tsunami, and are trying to restart the cooling system.
Emergency conditions at other 4 plants in the complex have also been announced.
Will continue researching and update any major developments over next couple hours, as they appear in comments or online.
Refs:
Xinhua
Huffpo Reuters repost
Al Jazeera rules.
They get so much traffic that their free website live stream can sometimes get laggy, even when their signal is not being jammed,
Their youtube channel live feed can tend to be more stable:
Al Jazeera Youtube Channel
You have to scroll down the page to the second video window, for the live stream
Fukushima Nuke Wiki