What is Nuclear Energy?

Of all the different energy sources that we employ to keep the world supplied with the electricity, nuclear energy is the most controversial. In the 1930s, splitting the atom was regarded as a tremendous scientific breakthough, but since then the energy that this unleashed – nuclear power – has had a chequered history.

Its associations with nuclear warfare, combined more recently with a few potentially disastrous radioactive leaks from nuclear reactors, have brought it bad press, and there are pressure groups who believe the dangers of using nuclear power outweigh the advantages. But we need to find alternatives to fossil fuels in order to combat climate change, and nuclear energy is one solution to this problem. Nuclear power stations produce no carbon dioxide emissions, because no combustion is involved.

Production of electricity is the only practical use of nuclear energy in the context of daily life. But whilst nuclear energy is limited in its applications, it is nonetheless important; nuclear power currently produces more than a tenth of all the electricity consumed around the world.

The Growth of the Nuclear Industry

Around the turn of the 20th century, scientists were fascinated by the notion of vast amounts of energy contained within one tiny atom, and experimental work on what was popularly termed ‘splitting the atom’ was being carried out independently in several countries. The atom was split in the UK in 1932, by scientists John Cockcroft and ETS Walton, and this was followed by further experiments on atom transformation.

Uranium was identified as a suitable element on which to conduct trials, and by 1935 scientists had carried out experiments from which they learned a great deal about radioactivity and chain reactions. By 1940 a theory of nuclear fission had been put forward, and by the time World War II began, scientific knowledge was sufficiently advanced to realise the possibilities of the atomic bomb. This was the beginning of the nuclear arms race, and during the decades that followed, nuclear power continued to be inextricably linked with warfare, with the result that public reaction to this newly-developed source of energy was very mixed.

Research into peaceful applications of nuclear power was being carried out alongside work on nuclear weapons. Electricity was first produced experimentally from nuclear power in America in December 1951, and was being produced commercially before the end of that decade. The world’s first industrial-scale nuclear reactor was completed in 1956 in the UK, at Calder Hall, in Cumbria. It had a dual purpose: to make plutonium, as part of the nuclear weapons programme, and to generate electricity which, it was claimed, would be ‘too cheap to meter’. Unfortunately this optimistic prediction did not come true; however, nuclear power stations are no more expensive to operate than fossil-fuelled ones.

Nuclear Fission and Nuclear Fusion

There are two ways of obtaining nuclear energy: by fission or by fusion. To date, electricity has been produced using energy from nuclear fission – releasing atomic energy by splitting the nucleus. Nuclear fusion is a process that takes place naturally in space; the energy of stars, including our sun, derives from nuclear fusion. Up to now, we have found it almost impossible to replicate this process because of the huge amounts of energy involved; the only way man has been able to generate nuclear fusion has been inside the hydrogen bomb. However, researchers now believe they may have developed a way of using controlled nuclear fusion to produce electricity, and if so, this may become the preferred method in the future.

The Future of Nuclear Power

Nuclear energy is a powerful force. Attempts have been made to find other constructive ways of harnessing it; possibilities that were identified included use as a fuel for space travel, and as an explosive device for blasting during major civil engineering works. Research into these and other possible uses was carried out during the second half of the 20th century, and trials into earth-moving by nuclear power were carried out in several countries. But concerns for public safety resulted in international agreement to call a halt to any further significant nuclear testing. However, a number of highly innovative applications of nuclear technology, for instance in medicine, have been developed.

It is likely that future research will concentrate on this type of highly specialist application, and on finding safer and more efficient ways of generating electricity and disposing of nuclear waste. Many countries, including the UK, have recently affirmed their intention to continue their use of nuclear energy for electricity generation, and although this decision has been condemned by anti-nuclear pressure groups, all the indications are that nuclear power will continue to be an important source of energy for us for a long time to come.