Journal Roblimo's Journal: Whatever Happened to “Gravity” Nuclear Reactor Safety Controls? 4
When I was a young teenager, one day my father took me to visit the then-new San Onofre Nuclear Generating Station. I recall quite clearly that the basic atomic pile control system was a series of control rods that would drop into the Uranium core in the event of a power or steam pressure loss and automatically shut down the reaction. WTF is up with reactors built since those early-generation Westinghouse ones that don't have this simple and obvious safety shutdown feature? Crazy.
From roblimo.com
Que? (Score:2)
What makes you think the reactors in Japan don't have control rods? I read that they did, but a. the quake damaged them, and b. even when you have control rods you still need to cool things down through additional means, like water.
Re: (Score:2)
Also, I wish I could find more information about the liklihood of nuclear material reaching the U.S. West Coast. I imagine we'll find out more throughout the next day.
Reactors need electricity (Score:2)
As I understand it, the problem was that the reactor couldn't cool itself because it had no electricity to run the cooling pumps.
The quake cut the power from the grid and the backup diesel generators were also destroyed. This left the final backup: batteries, which had about eight hours of juice in them.
Once the batteries were exhausted, there was nothing to cool the reactor and the pressure built up in the containment vessel.
You might find this article instructive... (Score:1)
Why I am not worried about Japan’s nuclear reactors [wordpress.com]
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Basically, the control rods works. But, while the nuclear chain reaction involving uranium stops immediately once the rods are in place, there is still a lot of nuclear decay happening of the various atomic fragments left over from the uranium splitting. These don't stop generating heat for a long time, and generate more heat than can be easily removed from the core for quite awhile.