Friday, March 16, 2007

The China Syndrome

Better late than never but I just watched the China Syndrome and I have to say that it is a pretty powerful movie. I've always been interested in nuclear power, both the good and the bad side of it. This movie takes nuclear fear a little too far I think. Recently I read a book by Bernard Cohen that a friend lent to me that tried to look at the dangers of nuclear power from a scientists stand point. It was really interesting to hear from a scientific point of view that nuclear power isn't as dangerous as the media would have you belive. Reporters only want to report the bad news. The China syndrome that the movie is named after is an exaggerated result of a nuclear melt down. The idea would be that the nuclear core would get so hot that it would burn its way through the earth and come out the other side in China. Needless to say this is perposterous for many reasons and very unlikely. The movie recieved a fair amount of criticism because it falsly makes the nuclear industry look much less safe and more accident prone that it actually is.

The biggest boost to this movie was the fact that the Three Mile Island accident happened a mere 12 days after the release of this film. This is unfortunate as it makes the movie seem all the more realistic and gave the anti-nuclear people a real boost. The ironic thing was that the Three Mile Island accident happened in much the same way as the accident in the movie. There was a failure of the coolant supply and the core partially melted. The main fact that people seem to avoid is in the TMI accident the highest dose recieved by anyone was only one third of what they would naturally get in one year. A China syndrome would be unlikely because the containment building of the reactor is designed to contain a meltdown. In the only full melt down the world has seen, Chernobyl, the core didn't pass through the earth and pop through the other side. The reactor had a large positive void coefficient which means the reactors power increases as coolant boils away.Now a large amount of radioactive material was released but Chernobyl did not have a full containment building around the reactor. Considering the number of reactors in the world this just goes to show that nuclear power can be safe if it is designed to be safe from the start.

Another point the movie brought up was the disposal of nuclear waste. Everyone is afraid of nuclear waste from reactors but they create far less waste than a coal power plant. A coal fired power plant may release as much as 5.2 tons of uranium per year. The energy in nuclear fuel is very high compared to the size of the fuel. "One uranium nuclear fuel pellet the size of the tip of your little finger is equivalent to the energy provided by 1,780 pounds of coal; or 149 gallons of oil, as much oil as fits in three 50 gallon drums; or 17,000 cubic feet of natural gas." this means that in 40 years of nuclear power there has only been 50,000 metric tons of waste produced. The would be enough to fill "a football field to a depth of about six yards". You have to remember that Uranium is very dense so it is very heavy compared to it's size. We aren't in an urgent situation to find new places to store the waste. When we have to start putting the waste undergound there is a process being considered called "Vitrificaiton" which basically turns the waste to glass which makes it less reactive with other materials. it is still quite radioactive but it will not react with ground water etc.

You may be wondering why we do not have nuclear power here in Saskatchewan but that is a discussion for another time.

I guess I got on a bit of a tangent there but I had to get that out. In summary I liked the movie for it's movie characteristics but take the science with a grain of salt.
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