Hazards From Radioactive Material | Radioactivity | Physics | FuseSchool

Summary

The video explains how radioactive waste can harm people, the difference between irradiation and contamination, and how radioactivity decreases over time.

• Radioactive waste can be produced by nuclear power generation, medical treatment, and scientific research.
• Irradiation occurs when a person or object is exposed to radiation without touching the radioactive source.
  • Exposure happens while the person is near the source, so the dose depends partly on how long they remain there.
  • Irradiation also has useful applications, including cancer treatment, sterilising surgical equipment, and reducing bacteria on fruit.
  • In these examples, the treated objects do not themselves become radioactive.
• Contamination occurs when radioactive material comes into contact with, or enters, a person.
  • The material may be carried away with the person, potentially prolonging exposure and increasing the dose.
  • Contamination can happen by touching radioactive material, breathing it in, or ingesting it.
  • Radioactive tracers are deliberately used in medicine to investigate possible blockages and to detect leaks in water pipes.
• Half-life is the time it takes for the amount of a radioactive substance to halve. The video illustrates this with a hypothetical kilogram of waste with a 100-year half-life: 500 grams’ worth remains after 100 years, and 250 grams’ worth after another 100 years. Radioactivity continues to decline over successive half-lives.
• Some radioactive waste can remain hazardous for thousands of years before its radiation falls to the level of background radiation. Background radiation comes from natural and artificial sources and is normally low.
• How harmful radioactive waste may be depends on its half-life and whether a person is irradiated or contaminated.

Speakers and sources featured

• Narrator: An unnamed narrator presenting the FuseSchool educational video.
• Other speakers: None identified.