Here is another perspective on this, from Scientific American. See if you can line up the facts from the two different articles.
I just got Karl Grossman on the phone — one of the leading anti-nuclear authors and professor of journalism at SUNY-Westbury. He has been following the situation at the Fukushima nuclear power plant described in the post below. Here is my understanding of the situation after our conversation.
When the quake happened this morning, both main and backup power went out at the Fukushima plant. The power runs pumps that circulate water to keep the reactor core cool. Whether the plant is in operation or not, the core must be kept cool. Once water stops circulating, operators have between 15 and 30 seconds before a meltdown begins — even if they get the reactor under control. That core has to be cooled at all times. So problem one is that the batteries have just eight hours of time, and that was a while ago.
A meltdown would inevitably cause a massive radiation release. Hence, I learned today that a light water reactor (the most common kind used commercially) is always between 15 and 30 seconds away from a meltdown.
Next problem is that there is a radiation leak inside the containment structure. He does not know the source of the leak, but it could be from the primary or secondary loop (a light water reactor has three loops that cool the core; the first and second are radioactive; the third is not supposed to be).
So they are venting radioactive vapor into the atmosphere to keep the pressure down. He believes workers are getting exposed to radiation.
“Now they are venting. There is so much radioactivity, and they’re trying to keep the water going,” Grossman said. “The challenge is to get the water flowing to cool down the reactor core. If it doesn’t you’re going to get damage to the fuel rods. Unless you’re cooling the core with water, it will go haywire,” which is a polite way of saying meltdown.
This would be called a loss of coolant accident — one of several major types of nuclear accidents that are possible.
The plant operators did what’s called a SCRAM maneuver and that was successful. SCRAM is shorthand for ‘safety control rod axe man’, named for one of the first nuclear pile experiments where a guy really was poised with an axe over a piece of rope that he was told to chop in a hurry if given the word.
“But there is extra radiation inside the containment structure and they have not explained why.”
To be continued. If you see news updates, please post them into the comments area. We are all citizen journalists now. Thank you.