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GCSE Questions: Energy Sources

Q23.

(a) Radioactive waste from nuclear power stations is a man-made source of background radiation.

Give one other man-made source of background radiation.

Any one from:

medical x-rays or CT-scans

radiotherapy

nuclear weapons (testing) or fallout

named nuclear disaster eg Chernobyl / Fukushima / Three Mile Island.

[1 mark]

(b) Nuclear power stations use the energy released by nuclear fission to generate electricity.

Give the name of one nuclear fuel.

uranium or plutonium

[1 mark]

(c) Nuclear fission releases energy.

Describe the process of nuclear fission inside a nuclear reactor.

A neutron is absorbed by a (large) nucleus ( NOT atom - that will negate the mark - you must say nucleus)

The nucleus ( NOT atom - that will negate the mark - you must say nucleus) splits into two (smaller) nuclei

Releasing energy (and gamma rays) and

Releasing (two / three) neutrons

[4 marks]

(e) A new type of power station is being developed that will generate electricity using nuclear fusion.

Explain how the process of nuclear fusion leads to the release of energy.

In nuclear fusion lighter nuclei join to form heavier nuclei.

When this happens some of the mass of the nuclei is converted to energy/gamma radiation.

Again you must say nuclei NOT atoms - that will negate the mark

[2 marks]

Nuclear fusion power stations will produce radioactive waste.

This waste will have a much shorter half-life than the radioactive waste from a nuclear fission power station.

Explain the advantage of the radioactive waste having a shorter half-life.

If the waste is of a short half-life the radioactive waste will decay at a greater rate, so its activity will decrease quickly and that means the time period in which there is a risk of harm will also decrease quickly. This means that the waste burial site doesn't need to be monitored for as long, or maybe it doesn't even need to be buried underground.

If you just said ' waste is radioactive for less time' you will get no marks - too vague! They wanted you to say why it being radioactive for less time is advantageous.

[2 marks]

(Total 10 marks)