OCR - P5: Radioactive materials

P5.3 How can radioactive materials be used to provide energy? (separate science only)
Background to the topic What you should be able to do:

Nuclear fuels are radioactive materials that release energy during changes in the nucleus.

In nuclear fission a neutron splits a large and unstable nucleus (such as some isotopes of uranium and plutonium) into two smaller parts, roughly equal in size, releasing more neutrons, which may go on to make further collisions.

Energy is released from the nucleus, carried away as kinetic energy of the particles and also by gamma radiation.

This release of energy from the nuclear store is analogous to that released from the chemical store of explosives like TNT but it is considerably larger.

If brought close enough together, hydrogen nuclei can fuse into helium nuclei, releasing energy, and this is called nuclear fusion.

The demand for energy is continually increasing and nuclear fuels are an alternative energy source to fossil fuels.

The risks and benefits need to be compared when making decisions about how to generate electricity.

1. Recall that some nuclei are unstable and may split into two nuclei and that this is called nuclear fission

In discussion of how electricity should be generated, you will discuss the risks and benefits of generating electricity using nuclear fission. Different decisions on the same issue might be appropriate in view of differences in personal, social, or economic context.

2. Relate the energy released during nuclear fission to the emission of ionising radiation and the kinetic energy of the resulting particles

3. Explain how nuclear fission can lead to further fission events in a chain reaction

4. Describe the process of nuclear fusion and recall that in this process some of the mass may be converted into the energy of radiation.