kolmapäev, märts 08, 2006


Inglise keele kirjand tuumaenergia kohta, kes tahavad, lugege, mul pohh.

Nuclear energy

During the quite short period of walking the earth, man has grown strong relations with combustion. Once upon a time tens of thousands of years ago, probarbly in a cold place, lightning hit ground somewhere near our ancestors, and they, soon after seeing fire lighting up, noticed that fire gave heat. We do not know how long it took before man noticed other fire?s properties: it frightened wild animals, the fact that it generated heat made it usable for keeping warm, and that fire used up fuel, which was mainly wood. At one point people decided to hang out around the forest fire for a while. When the fire started to die, one man, the greatest thinker of all time, took a burning stick and went back to camp with it. There they put additional pegs on the burning stick and they caught fire. Fire had been domesticated! In some time, people learned to produce artificial fire themselves, using wood or flintstones.

Millenniums passed, but the utilization of combustion stayed the same. People did not depend on it so much, they were perfectly able to live without it. Sure, with more people came more fire, but the amount was not drastic.

With larger wars, however, came the use of fire in war. Fortifications could be destroyed by lighting them on fire, and whole forts were often burnt down.

Some two thousand years ago, the chinese learned to use burning powder for fireworks. They did not, however, realise that it could be used for militaristic reasons. But with the discovery of gunpowder in early medieval Europe, wars changed drastically. I will, however, not go into the details of this.

The first steam engine was patented in 1698 and with it came over two centuries of man?s extensive use of coal. Transportation began to evolve with awesome speed, and the steam engine soon became too unefficient for transportation to evolve further. Gas was attempted to be used, but without enough luck for the projects to succeed. In the late 19th century, Gottlieb Daimler and Carl Benz separately came up with the idea of an internal combustion engine that ran on gasoline, and both were successful. Today, most cars use gasoline. There are over 500 million cars in the world, and 99.9(9) percent use fossil fuels. But humans still need heat, and in the last hundred years, we have also grown fond of electricity. Both are mostly produced of fossil fuels. But fossil fuels, also called nonreproducable resourves, are not reproducable. And they are running out. So, the first thing we have to do is to cut our energy consumption. But this is not enough, we must use alternative energy resources. In the future, it seems certain that the main powersource will be nuclear fusion, but today the technology for it is not advanced enough for it to pay, but even today a fusion plant is being built that will itself generate enough electricity to power itself. But we are still decades away from extensive use of fusion plants, so we have to settle with other powersources.

Wind and water has been utilized to work for us for thousands of years, but they, as combustion, are not too efficient. In recent years, solar power has been used more and more, but the efficiency is not not near to perfect there either.

At 05:29:45 on July 16, 1945, a bright flash in New Mexico, USA, demonstrated that the world had reached the nuclear age. In a few months, two atomic bombs, one plutonium and one uranium, were dropped on Japan. But it had already been understood that a nuclear reactor, in addition to its military use of creating plutonium, can be used to produce power. On December 20, 1951, electric power from a nuclear powered generator was produced for the first time at Experimental Breeder Reactor-I located near Arco, Idaho. On June 27, 1954, the world's first nuclear power plant for a practical, commercial purpose began operations at Obninsk, Russia. Today, there are 441 commercial nuclear reactors worldwide.

About 24 nuclear powerplants are to be built or reconditioned during the next five years in Canada, China, several European Union countries, India, Iran, Pakistan, Russia, and South Africa. But with new nuclear power plants comes the question: is it the ?right? way to obtain power? Nuclear reactors can ?meltdown?, which means that the uranium rods catch fire, and the temperature skyrockets. This can lead to a nuclear explosion, although the structural differences between a real nuclear bomb and a reactor means that the explosion would be a small one. There have been only a handful of core accidents, and most were partial meltdowns (and a few more in Soviet submarines). There have actually been three partial meltdowns in the United States, and one in the former Soviet union (with a few more around the rest of the globe). But the one in the soviet union, the Chernobyl incident, is the only one which was a full meltdown and where radioactive matter was released into atmosphere. The nearby population was evacuated, but still suffered from the irradiation. The bizarre fact about Chernobyl is that the evacuated area is today, as man has left, the cleanest part of Ukraine. The surrounding area is still contaminated, though not very much as it is still being cleaned up.

This year, the Chernobyl accident turns 20. Since then, nothing has happened. The three last accidents happened in 1986, 1979 and 1967. So there?s quite a large timegap between any incidents. Most of the incidents with nuclear reactors are due to human error, mainly lack of cooling. With todays technology, the computers backing us up, this human error factor should be suppressed as low as it can go, so this problem has almost ceased to exist (even if you wanted, it would probarbly not be easy to trigger meltdown. The computers in the plants are really fool-proof).

We should think about the fact that traditional, coal- and oil-based plants are definitely not safe either. Let us assume that one nuclear plant produced the power of five coal-based plants. Now we must consider how many workers are killed during the mining of all the coal that is needed, one ton of uranium contains the energy of millions of tons of coal. And the emissions that are created by the coalplants are not safe either. The problem is that traditional powerplants DO create emissions, but the only certain emission of nuclear plants is dihydrogenmonooxide, which, as we know, is water, and it is not ?produced? either, it is taken from nature and released there too, as vapour. Of course there is nuclear waste, but 1/3 of it is plutonium, which can be reused, and the rest is buried deep underground, where nothing escapes. And it DOES actually decompose, in the long run.

There is always a possibility of sabotage at the plant, for example with a bomb. The only ?problem? with that is that the reactor is shielded, by reinforced concrete blocks, weighing thousands of tonnes. A test was carried out, essentially a crash-test with a figthter aircraft (the F-4 Phantom) that was launched at a simulated, protected reactor at 600 knots. The reactor survived perfectly. So, to get the lid off, to get the fuel, to make atomic or ?dirty? bombs, you quite literally need another atomic bomb to blow it up.

I am a passionate supporter of atomic energy, and I would like to see more people like me.

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