Topic 4 Background Raduation Amd Contamination Flashcards
What is background radiation
Low level radiation that is around us all the time
What should you always do with the back ground radiation
Measure it and subtract it from your result
What is radiation from space called
Cosmic rays and mostly come from the sun
What protects us from most cosmic waves
Earth’s atmosphere
What is radiation due to human activity
Fallout from nuclear explosions or nuclear waste
But this only makes up a tiny percentage of background radiation
What does a radiation dose tell you
The risk of harm to body tissues due to exposure to radiation
What is the radiation dose measured in
Sieverts
What is back ground radiation often measured in
Millisieverts
1sv = 1000 msv
What does back round radiation dose depend on
Where you live
What is exposure to radiation called
Irradiation
What does irradiating not do
Make something radioactive
What are ways to reduce the effects of irradiation
Keep sources in lead lined boxes
Stand behind Barriers
In a different room
Use remote controlled arms
What is contamination
Unwanted radioactive atoms get onto or into an object
Why might contamination cause you harm
Contaminating atoms might decay releasing radiation and cause you harm
Why is contamination especially dangerous
Radioactive particles could get inside your body
What should be worn to protect yourself
Gloves and tongs should be used when handling sources to stop them getting stuck to skin or under nails
Some industrial workers wear protective suits to stop them breathing in the particles
What does the seriousness of irradiation and contamination depend on
The source
What are most dangerous outside the body
Beta and gamma sources
As they can penetrate into the body and get to delicate organs
Why is alpha less dangerous outside the body
Can’t penetrate skin and is easily blocked by a small air gap
What sources are most dangerous inside the body
Alpha sources because they do all their damage in a very localised area. So contamination is more of a concern than irradiation
Why are beta sources less damaging inside the body
As radiation is absorbe over a wider area and some passes out of the body all together
Why are gamma sources the least dangerous inside the body
As they mostly pass straight out and have the least ionising power
How are ideas about radiation improving
Data is peer reviewed and can quickly become accepted leading to many improvements in our sue of radioactive sources
