What does phosphoresces mean?
Emits light
Who discovered radioactivity?
Henri Becquerel
What can ionising radiation cause?
- tissue damage such as reddened skin (radiation burns)
- cancer from mutations
How is cancer caused by ionising radiation?
It damages the DNA inside the cell causing mutations, which may make the cell malfunction and cause cancer
How can you decrease the risk of radioactive substances?
- decreasing the distance from the source
- not pointing the sources at people
- keeping sources in a lead-lined container
What does HLW stand for?
High level waste
For how long does HLW produce ionising radiation for?
50 years
What does LLW stand for?
Low level waste
How is high level waste transported?
Inside concrete and steel containers which absorb radiation
How is HLW stored?
The concrete and steel containers are sealed in a glass top to stop radioactive material escaping and stored in canisters until the waste is less radioactive
How is ILW stored?
In concrete and steel containers
How is LLW stored?
It’s compacted and buried in special landfill sites because of the possibility of radioactive material leaking into soil or water
What are three methods of disposal of nuclear waste?
- firing it into space
- dumping barrels at sea
- storage underground
What is the disadvantage of firing nuclear waste into space?
The launch vehicle could fall back on to Earth, spreading radioactive material over a wide area
What is the disadvantage of dumping barrels of nuclear waste at sea?
The barrels can corrode and release radioactive materials that could enter the food chain
What condition must a site meet in order for nuclear waste to be stored underground?
It needs to be geologically stable(low risk of earthquakes)
Does a nuclear power station itself produce carbon dioxide?
No
What part in the process of making nuclear power might contribute to global warming?
The making of the fuel rods
Why does nuclear waste have to be stored for tens of thousands of years?
So that the radioactivity has decreased to safer levels
Why do some people think nuclear power is unsafe?
Because of the risk of accidents
What does activity in a radioactive substance mean?
The number of nuclear decays per second
What is the activity of a radioactive substance measured in?
Becquerel (Bq)
Why can’t you predict when radioactive decay will happen?
It is a random process
What is half-life?
The time taken for half the unstable nuclei in a sample of a radioactive isotope to decay
What happens to the activity of a substance as it gets more stable nuclei?
It gets lower
How is the radioactivity of a source measured?
By using a Geiger-Müller (GM) tube
What can be used to model radioactive decay?
Flipping a coin
Why is flipping a coin an effective model for radioactive decay?
- both have two options (heads/tails and decayed/undecayed)
- both are a random process
What is background radiation?
Low levels of ionising radiation from space and naturally radioactive substances in the environment
What must scientists subtract when getting the reading of the activity of a source?
The background count
What causes half of background radiation in the UK?
Radon gas
Where does radon gas come from?
The decay of uranium in rocks
What is the half-life of radon?
3.8 days
What does radon give out when it decays?
An alpha particle
What does the amount of radon in the air depend on?
- the type of rock it’s coming from
- its uranium content
How can you get rid of radon in a house?
By using a radon outlet pipe
When is radiation used to sterilise things?
When the equipement being sterilised cannot be heated instead
