A bit more on the Japanese reactors
Here is a reporter who gets it. From Natalie Wolchover at
FOX News:
Earthquakes Put Japan's Nuclear Reactors on Red Alert
The 8.9-magnitude earthquake that shook Japan early March 11 blew out the cooling systems of two nuclear reactors there. An inability to cool the reactors could cause radiation leaks, and both power plants are "bracing for the worst,� according to government officials.
"At present we have no reports of any radioactive materials or otherwise affecting the surrounding areas," Japanese Prime Minister Naoto Kan told the press. The malfunctions are occuring at the Tokyo Electric Power Co.'s Fukushima Daiichi power plant near Tokyo and the Tohoku Electric Power Co. facility in Onagawa. Chief Cabinet Secretary Yukio Edano said that all the necessary precautions are being taken to prepare for radiation leaks, including evacuating thousands of residents within a 3-mile radius of the Fukushima facility.
Eleven reactors nearest the quake's epicenter automatically shut down upon sensing vibrations in the early hours of March 11. "Reactors shut themselves down automatically when something called 'ground acceleration' is registered at a certain point, which is usually quite small. It will instantly drop control rods into the [nuclear] core," Professor Tim Albram, a nuclear fuel engineer at the University of Manchester in the U.K., explained to the press.
Those control rods block neutrons from entering the core and inducing the fission reactions that produce nuclear energy. When the rods drop into the core, the heat put out by the nuclear fuel rods they surround plummets instantly, reducing the core's temperature to less than 5 percent of normal in a matter of seconds.
You have a contingency plan. The reactors self-monitor and if there is any kind of excursion outside their operating boundary, they scram the control rods and shut down. The heat inside the core drops to 5% within a few seconds.
Just. In. Case. you evacuate people within a one kilometer radius and tell people within a five kilometer radius to stay indoors.
This is a serious event -- not trying to sugar-coat it but the possibilities are known and engineered for...
Posted by DaveH at March 11, 2011 10:59 AM