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Background Radiation
Lesson ObjectivesTo understand basic ideas
about nuclear radiation
Learning OutcomesTo be able to use ideas
about nuclear radiation and apply them to everyday
scenarios
Success Criteria
Good if: you can name three radioactive materials and explain how we measure nuclear radiation.Excellent when: you can explain what is meant by background radiation and how we must account for it when carrying out radiation experiments.Exceptional if: you can apply ideas about radiation all around us to the idea of acceptable risk.
How can radiation be detected?Radiation is all around us – naturally occurring, and man-made sources, but it is invisible, so how do we actually know it’s there?
The effects of radiation can be seen and so it can detected using instruments such as a Geiger-Müller tube.
This is a device that can detect and measure radiation.
Radioactivity can also be detected by the presence of photographic film, which darkens when struck by radiation. This effect lead to the initial discovery of radioactivity more than one hundred years ago.
Background Radiation is all around us!We are constantly being bombarded by radiation from our surroundings, known as background radiation. A radioactive of Carbon is created in the upper atmosphere and absorbed by plants. This means that radiation is present throughout the food chain. Background radiation is due to:
• Radioactivity in all plants and animals
• Radiation from the Sun and space.
• Radiation from buildings.
• Radiation from the ground.
• Radiation from hospitals and other users of radioactive materials.
• Radiation from waste leaks and from nuclear power stations.
Radiation dose is measured in millisieverts (mSv). The average UK radiation dose is 2.4 mSv per year.
DANGER: BANANASBananas are one of the most radioactive foods you can eat due to the high percentage of radioisotope potassium-40 which they contain.
They are so radioactive that containers of bananas frequently set of radiation detectors in airports.
The Banana Equivalent Dose (the amount of radiation from the consumption of one banana) is often used to give a scale to radiation leaks as an alternative to standard units such as μSieverts (1 banana = 0.36 μSieverts).
Radon – The Silent Killer!
Radon is a hazardous gas. It is produced naturally in rocks. Granite rock emits radon gas which is a particular hazard if it builds up in enclosed spaces and is breathed in.
Depending on the bedrock beneath the ground radon hazards are different around the country.
Radon gas emits alpha radiation. Exposure to a source outside your body is called irradiation. If radiation gets inside your body it is called contamination.
Radon is not an irradiation risk, however if you become contaminated the risk could be severe; you may die or become very ill!
Lesson ObjectivesTo understand basic ideas
about nuclear radiation
Learning OutcomesTo be able to use ideas
about nuclear radiation and apply them to everyday
scenarios
Success Criteria
Good if: you can name three radioactive materials and explain how we measure nuclear radiation.Excellent when: you can explain what is meant by background radiation and how we must account for it when carrying out radiation experiments.Exceptional if: you can apply ideas about radiation all around us to the idea of acceptable risk.
