Do you remember the content of I/GCSE Physics regarding radian types? 👨🏫
Now we will look at the uses of Nuclear Radiation!
Alpha Radiation in Smoke Detectors
- Smoke detectors have a weak source of alpha radiation close to 2 electrodes
- The radiation ionises the air and a current flows between the electrodes
- If there’s a fire, the smoke absorbs the radiation, making the current stop flowing
- The alarm then sounds

Beta Radiation in Tracers
- Radioactive substances can be used as medical tracers
- If a radioactive source is injected into a patient or swallowed, its progress around the body can be followed using an external radiation detector
- A computer converts the reading into a TV display showing where the strongest reading is coming from
- The tracers can show if the body is working properly
- Doctors use beta or gamma radiation, as this radiation passes out of the body. They also use substances that are only radioactive for a few hours
Beta Radiation in Thickness Gauges
- Beta radiation is used in thickness control
- You direct radiation through the thing being made, e.g. paper, and put a detector on the other side, connected to a control unit
- When the amount of detected radiation goes down, it means the paper is coming out too thick, so the control unit pinches the rollers up to make it thinner
- If the reading goes up, the paper’s too thin, so the control unit opens the rollers up a bit
- For this use, the radioactive substance mustn’t decay too quickly, otherwise its strength would gradually fall and the control unit would keep pinching the rollers trying to compensate
- You need to use a beta source, because then the paper will partly block the radiation. If it all goes through (or if none of it does), then the reading won’t change at all as the thickness changes

Medical Uses of Gamma Radiation
- High doses of gamma radiation will kill all living cells, so they can be used to treat cancers
- The gamma rays need to be directed carefully at the cancer and at just the right dosage so that the cancerous cells die without damaging any normal cells
- They are also used to sterilise medical equipment by killing microbes
- This is better than trying to boil plastic instruments which might be damaged at high temperatures
- You need a strong radioactive source that lasts a long time, so that it doesn’t need replacing often
Industrial Uses of Gamma Radiation
- Industries use gamma radiation to do non-destructive testing
- Airlines can check the turbine blades of jet engines by directing gamma rays at them
- If too much radiation gets through the blade to the detector on the other side, they know the blade’s cracked or there’s a fault in the welding

Nuclear Power
Uranium as a Nuclear Power Fuel
In nuclear fission, atoms in the uranium are split in 2, releasing lots of energy. Water is used as a coolant to take away the heat produced by the fission process. This heat is used to produce steam to drive a turbine and generator.

Advantages of Nuclear Power
- Nuclear power stations can make lots of energy without releasing lots of carbon dioxide into the atmosphere, reducing global warming
- Nuclear reactions release a lot more energy than chemical reactions such as burning, so less uranium is needed to produce the same amount of power as fossil fuel
- Nuclear fuel is relatively cheap
- There’s lots of uranium in the ground
Disadvantages of Nuclear Power
- Nuclear power stations are expensive to build and maintain
- It takes longer to start up the power stations than starting up a fossil fuel power station
- Processing the uranium before use causes pollution
- There are risks of radioactive leaks or a disaster like Chernobyl
- Nuclear waste produced is dangerous to dispose of
- Nuclear power stations have to be decommissioned after they are not in use which is expensive
- Uranium is a non renewable source, so will eventually run out
Nuclear Weapons
- The used uranium fuel from nuclear power stations can be reprocessed
- This is one way of dealing with some of the radioactive waste that would otherwise have to be stored
- After reprocessing, you’re left with more uranium and some plutonium
- The uranium can be reused in a nuclear power station and the plutonium can be used for nuclear bombs
Since there's danger from Radioactive Materials, so protection is needed around Radioactive sources:
- Radioactive sources need to be stored safely by being kept in a labelled lead box
- They should also be put back in shortly after use to reduce your exposure time
- Radioactive substances should always be handled with tongs so that skin contact is avoided
- They should be held at arms length and kept pointing away from you. Also, avoid looking directly at it
Industrial workers wear full protective suits to prevent radioactive particles being inhaled, or attaching to the skin or under fingernails
Lead-lined suits, lead or concrete barriers and thick led screens shield workers from gamma rays in highly radioactuve
Reference:
https://www.world-nuclear.org/information-library/nuclear-fuel-cycle/introduction/what-is-uranium-how-does-it-work.aspx
This is the end of the topic!

Drafted by Cherry (Chemistry)