4.5 Nuclear fission and fusion  (Page 2/4)

But there have also been serious setbacks. India and Pakistan, which never signed the treaty, became new nuclear powers, shocking the world with test explosions in 1998. The current issue of nuclear weapons testing in North Korea, is another such setback and a blow to the treaty.

Group discussion questions:

1. Discuss what is meant by an 'arms race' and a 'treaty'.
2. Do you think it is important to have such treaties in place to control the testing and use of nuclear weapons? Explain your answer.
3. Discuss some of the reasons why countries might not agree to be part of a nuclear weapons treaty.
4. How would you feel if South Africa decided to develop its own nuclear weapons?

Nuclear power - harnessing energy

However, nuclear fission can also be carried out in a controlled way in a nuclear reactor . A nuclear reactor is a piece of equpiment where nuclear chain reactions can be started in a controlled and sustained way. This is different from a nuclear explosion where the chain reaction occurs in seconds. The most important use of nuclear reactors at the moment is to produce electrical power , and most of these nuclear reactors use nuclear fission. A nuclear fuel is a chemical isotope that can keep a fission chain reaction going. The most common isotopes that are used are Uranium-235 and Plutonium-239. The amount of free energy that is in nuclear fuels is far greater than the energy in a similar amount of other fuels such as gasoline. In many countries, nuclear power is seen as a relatively environmentally friendly alternative to fossil fuels, which release large amounts of greenhouse gases, and are also non-renewable resources. However, one of the concerns around the use of nuclear power is the production of nuclear waste , which contains radioactive chemical elements.

Debate : nuclear power

The use of nuclear power as a source of energy has been a subject of much debate. There are many advantages of nuclear power over other energy sources. These include the large amount of energy that can be produced at a small plant, little atmospheric pollution and the small quantity of waste. However there are also disadvantages. These include the expense of maintaining nuclear power stations, the huge impact that an accident could have as well as the disposal of dangerous nuclear waste.

Use these ideas as a starting point for a class debate.

Nuclear power - An energy alternative or environmental hazard?

Your teacher will divide the class into teams. Some of the teams will be 'pro' nuclear power while the others will be 'anti' nuclear power.

Nuclear fusion

Nuclear fusion is the joining together of the nuclei of two atoms to form a heavier nucleus. If the atoms involved are small, this process is accompanied by the release of energy. It is the nuclear fusion of elements that causes stars to shine and hydrogen bombs to explode. As with nuclear fission then, there are both positive and negative uses of nuclear fusion.

Nuclear fusion

The joining together of the nuclei of two atoms to form a larger nucleus.