On March 10, a massive earthquake occurred just off the coast of Japan. Immediate devastation occurred with the shaking and following tsunami. Then a new danger arose: the quake had damaged Japan’s nuclear power infrastructure and there was a possibility of a major meltdown. Physics professor Jim Borgardt explains more about nuclear reactors:
What exactly is happening in the nuclear reactors in Japan?
A nuclear power plant works much the way a coal or any other power plant works. There is a heat source that turns water into steam, driving a turbine that creates electricity. The only difference is, in a nuclear power plant the heat source is nuclear fission, which is much hotter than, say, coal fire. It is so hot in fact that for the fuel rods to remain in a solid state, they must be constantly cooled with water controlled by pumps. The earthquake knocked out the power to these pumps; there were backup pumps, but the quake was strong enough to knock these out as well. So the reactions are continuing and heat is being generated, but the water is not circulating to cool it. It turns to steam and the water level drops, exposing the fuel rods even more. They can get so hot that they melt themselves.
Is that what a “meltdown” is?
Yes, it makes it harder to contain and can possibly even melt through the containment unit. There was a film a while back called the “China Syndrome” that theorized a fuel rod melting all the way to China. Which is of course ridiculous, but you get the point. The heated water vapor can build up pressure and possibly explode, there have been some cracks found in the outer shell.
What are the radioactive chemicals that could be released?
The two main ones are cesium-137 and iodine-131. I-131 decays in just a few days, but it is a concern is because your thyroid can mistake it for normal iodide and absorb it. They have been combating this by giving people pills of iodide-133 and filling up the thyroid so that it doesn’t take up any poisonous I-131.
Cesium-137 is the biggest danger because it does not decay quickly and persists in the environment. If you noticed in the newspapers, they were warning people to avoid dairy products from the area, it’s because radioactive particles get on the grass, cows eat the grass and the particles get into the milk.
I don’t see a future for this power plant. I think they’ll just encase it in concrete like a big sarcophagus.
Should people be worried?
The media has really blown out of proportion the dangers of radiation. The only people in danger are the workers in the plants or the people in the immediate blast area. We all receive radiation daily from nature; cosmic rays, even cigarettes are slightly radioactive. There’s no clear line when it becomes dangerous, so we simply use it as a reference point for measuring radiation intake.
The problem is, people have such a fear of radiation: it’s invisible, soundless, tasteless, odorless and can potentially kill you. The media has created such paranoia about nuclear technology that it’s impeding the advancement of the technology. No new plants have been started since 1974, even though much better, safer technology now exists. Think of it this way: car accidents hardly ever make news, they are too common and just part of our culture. But plane crashes create a big stir and cause people to fear flying, even though it is statistically much safer than driving. Coal power kills about 20,000 people a year because of its toxic pollutants in fact it even emits more radiation into the atmosphere than nuclear. Nuclear power does very little relatively. As you can see, though, if something goes wrong it’s all over the news for days.
-Joe Aultman-Moore ’12, Juniata Online Journalist