P 5.2 How can radioactive materials be used safely?

In the UK some vegetables are sterilised by radiation during processing in order to extend their shelf-life.

The radiation is from a radioactive source.

A label on the pack states that the vegetables have been irradiated.

Donna is shopping and reads the information on the pack. She expresses her concerns to her friend.

‘I’m worried that I will be contaminated if I eat these vegetables.’

Explain how irradiating vegetables extends their shelf-life and give reasons why Donna’s concerns are unfounded. [6 Marks]

Pete expresses another concern to Ali.

Suggest reasons why Pete over-estimates the risks from a nuclear accident at a power station. [3 Marks]

People who work in nuclear power stations wear a badge to monitor the type of ionising radiation they are exposed to.

One type of badge consists of a photographic film behind three windows made of different materials, aluminium, lead and card.

The film becomes fogged (darkened) if radiation passes through the window.

Fogged areas are shown as in the following diagrams.

Suggest why this badge cannot be used to detect α radiation. [1 Mark]

The radioactive waste from nuclear power stations can be a hazard through contamination or irradiation.

Which of the following statements are correct? Choose two.

• Contamination results in a long period of exposure to radiation.

• Contamination causes cancer, but irradiation just damages cells.

• Ionising radiation causes contamination.

• Exposure to radiation from an external source is irradiation.

• Protective clothing mainly protects from irradiation.

Read the following article. Which one of the following phrase is correct for 'radioactive source'?

• particles or waves that can break

  apart atoms

• a substance that produces alpha, beta or gamma radiation

• the time taken for half of a radioactive substance to turn into another substance

• the particles in a sample naturally change from one element to another

• energy is released by a chain reaction

Read the following article. Which one of the following phrase is correct for 'ionising radiation'?

• particles or waves that can break

  apart atoms

• a substance that produces alpha, beta or gamma radiation

• the time taken for half of a radioactive substance to turn into another substance

• the particles in a sample naturally change from one element to another

• energy is released by a chain reaction

Read the following article. Which one of the following phrase is correct for 'decay'?

• particles or waves that can break

  apart atoms

• a substance that produces alpha, beta or gamma radiation

• the time taken for half of a radioactive substance to turn into another substance

• the particles in a sample naturally change from one element to another

• energy is released by a chain reaction

Radioactive sources are used in medicine.

Which of the following use radioactive sources? Pick three.

• treating cancer

• sterilising surgical instruments

• using a tracer in the body

• using a vaccine

• using X-rays

Priya is going to work in a laboratory where radioactive sources are used.

She knows that radioactive sources can be dangerous.

Her supervisor has reassured her that the risk is low if she follows the safety procedures.

What are the risks from handling radioactive sources and how do these safety procedures reduce the risks? [6 Marks]

People working with radioactive sources often wear detectors to measure how much ionising radiation they are exposed to.

One type of detector is a badge with photographic film covered by three different materials.

The photographic film records the amount of radiation that reaches it.

The badge has three sections.

Which sections can be used to detect beta and gamma radiation? [2 Marks]