I selected this topic because I have always been interested in nuclear technologies, nuclear energy and its application in modern apparati such as power plants and submarines. The second reason that conduced me to write about this theme is that it is a very “thorny” problem. And I’m not surprised. Many people are afraid of Temelín and nuclear power plants,
for they still brightly remember the explosion of Russian atomic power station in Černobyl and the consequences that have had an impact on east European nations to this day.
Firs of all, I would like to shed light on the matter of the accident
in Černobyl. We should blame no one but the irresponsible engineers
and technicians, who were also, I daresay, quite a bit stupid. It was all their fault. It was a matter of the human factor, not a matter of technology.
It all started when the employees of Černobyl decided to do lots
of unimportant tests and experiments with one of the reactors. A sane person would not do that. Not in a power plant on stream. It’s just a foolish thing to do. But Russian “experts” wanted to make some inconsequential benchmarks …
Normally, you wouldn’t be able to do that, because there are many security systems that would stop you. But engineers gradually switched all of them off and when they spoiled the hazardous experiment with reactor’s adjusting rods by inserting them into a reactor’s core for exceedingly long time, the catastrophe was inevitable. In a few minutes, the reactor’s output, temperature and pressure inside it surpassed more than 100 times its maximum level. Then the reactor blew up. However, if technicians hadn’t made five or six fatal mistakes and if they hadn’t disconnected all security systems, automatic control systems and alarms, many innocent folks wouldn’t have had to die. And people all around the world wouldn’t
be so afraid of atomic energy.
The fuel for nuclear fission is a special isotope of metal uranium called U-235, which has 235 nucleons in its core. When a neutron hits such an atom of uranium, it splits it into two smaller ones. With this process, two or three neutrons “fly” speedily out of the dissociated nucleus, dissociate other atoms and unleash more neutrons and energy from their cores. Thus the procedure goes on. This is how the chain reaction works.
And how does it all work in an atomic power plant? The reactor, wherein the chain reaction runs, is cooled by cold water. The water flows through the pile, vaporizes into steam and then reels the turbine that drives
the generator. After that the steam condenses and as water flows back into the reactor’s core. Adjusting rods, which are mostly manufactured
out of cadmium or boron, regulate the speed of the nuclear reaction.
The greatest advantage is that generating electric current by nuclear reaction is extremely effective. Up to now, there has been no more efficient way discovered. One kilogram of dissociated uranium unleashes the amount of energy equal to energy acquired by burning 25 tons of top black coal. Imagine that! That’s 25,000 times more! Not to mention the devastated landscape and highly polluted air after coal mining.
Another advantage, which is perhaps just plain fact, is that there’s still enough uranium to use. As we all know, the resources of both black and brown coal are decreasing and soon, all of the mines will
be exhausted. And regrettably, there aren’t many places where you could effectively utilize solar energy, geothermal energy, waterpower
or airpower. All the same, the effectiveness of such resources of power
is relatively insufficient. So for the time being, the atomic power plants
are the only usable solutions.
Nor is the fact that nuclear power stations do not pollute air
and produce minimum of unwanted spillower products in contradistinction to other industrial facilities omissible. Average atomic power plants produce just some 60 kilograms of highly radioactive toxic waste per year. Which is, on the other hand, rather disadvantageous.
In fact, that’s a big problem. Approximately 2 per cent of these materials, such as plutonium, are frightfully dangerous substances.
They need up to 1000 years to decompose, so that they aren’t radioactive
and don’t ruin our health (by the way, if you inhale just one-millionth gram of plutonium, you are taken ill with cancer). The only available
and reasonable solution is to store this fall-out in highly secured places.
Many objectors of nuclear energy and power stations are afraid
of another atomic breakdown like in Černobyl. It’s really bad that lots
of them don’t know the true circumstances that were the cause of the disaster. Nevertheless, the reactor blew up and lots of people died or fell ill mostly with cancer or other horrific diseases. And therefore
we must be very careful and cautious when working with atomic energy.
The last important negative is that despite thorough protection against radioactivity from the uranium used in a reactor, the small amount of radiance still gets out from a power plant. But since this radiance
represents less than one-hundredth part of the natural sources
of radioactivity such as minerals or rocks, this emission is completely imponderable.
I myself am for nuclear power plants because they are very efficient and they have almost no effect on the environment. Even though
the running of them can be quite dangerous in a way, it’s still the only solution for generating a sufficient amount of electric energy after we will have exploited all stocks of coal, petroleum and natural gas.
9. červenec 2008