If you compare one of the new atomic power stations with the coal-burning power stations of the past that we are used to seeing, you will immediately notice a big difference—everything is so clean. You will also miss the great chimneys and piled of coal and noisy machinery that were part of the old kind of power stations.
These are the signs of the new age which are quickly seen, but there are others which take a little longer to notice. If there is no dirt, then the building of the power station can be made to look more beautiful. Bright colours can be used. Calder Hall, in Cumberland,
English opened in 1956, is a good example of this. The central buildings of this station which contain the great atomic reactors and are as big as cinemas, have four boilers, or ‘heat-exchangers’, one at each corner of the building. Each of them was a different colour. There is a bright blue one, a yellow and a green one.
These colours all help give you a feeling that are seeing something new as you approach the station. It is true there are still two small chimneys on the roof that remind you a little of the funnels of a Mississippi pleasure both, but there are not for smoke or steam. You will never see any gases leaving them. Their only purpose is to pass the cooling air into the sky overhead.
Inside the station you will find everything perfectly clear, just like a hospital. There are two reasons for this. The first is that if dirt were allowed to mix with the atomic fuel or in any other way to get into the reactor, it might possibly stop the reactor working, or at least slow it down so that the expensive fuel, which had been spoilt by the dirt, had to be changed for new. The other reasons is that dirt is hard to control. If dirt from inside the atomic pile, by carelessness or some chance, happened to get mixed up with dirt outside, people both inside and outside the power station would be harmed by it.
A drawer contains two coins: one coin has head on both the sides. The other coin has a head on one side and a tail on the other side. One coin is drawn from the drawer and its face is observed. If the face is head, what is the probability that the other face is head also?