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GCSE Questions: Energy Sources

Q15. Many countries use nuclear power stations to generate electricity. Nuclear power stations use the process of nuclear fission to release energy.

(a)

(i) What is nuclear fission?

[1 mark]

(ii) Plutonium-239 is one substance used as a fuel in a nuclear reactor.

For nuclear fission to happen, the nucleus must absorb a particle. What type of particle must be absorbed?

[1 mark]

(b) Nuclear fusion also releases energy.

Nuclear fusion happens at very high temperatures. A high temperature is needed to overcome the repulsion force between the nuclei.

(i) Why is there a repulsion force between the nuclei of atoms?

[1 mark]

(ii) Where does nuclear fusion happen naturally?

[1 mark]

(c) In 1991, scientists produced the first controlled release of energy from an experimental nuclear fusion reactor.

This was achieved by fusing the hydrogen isotopes, deuterium and tritium. Deuterium is naturally occurring and can easily be extracted from seawater.

Tritium can be produced from lithium. Lithium is also found in seawater.

The table below gives the energy released from 1 kg of fusion fuel and from 1 kg of fission fuel.

Type of fuel
Energy released from 1 kg of fuel/J
Fusion fuel
3.4 × 1014
Fission fuel
8.8 × 1013

 

(i) Suggest two advantages of the fuel used in a fusion reactor compared with plutonium and the other substances used as fuel in a fission reactor.

[2 marks]

(ii) Some scientists think that by the year 2050 a nuclear fusion power station capable of generating electricity on a large scale will have been developed. Suggest one important consequence of developing nuclear fusion power stations to generate electricity.

[1 mark]

(d) Tritium is radioactive. After 36 years, only 10 g of tritium remains from an original sample of 80 g. Calculate the half-life of tritium. Show clearly how you work out your answer.

[2 marks]

(Total 9 marks)