Natural and human made radiation
Radiation is energy travelling from one place to another in the form of waves or particles. We encounter radiation in the natural environment. It can also be human made.
Natural sources of radiation include:
- soil
- rocks
- water
- air
- vegetation.
We use radiation in processes we rely on every day. For example:
- x-rays
- CT scans.
Usually, radiation poses little to no health hazards. But it depends on the type and amount of radiation.
Types of radiation
There are 2 main types.
Non-ionising radiation
This type of radiation transmits energy but is not energetic enough to detach electrons from atoms or molecules.
Sources include:
- UV radiation from the sun
- extremely low frequency (ELF) radiation from powerlines
- electro-magnetic radiation in microwave ovens
- radiofrequency energy that mobile phone systems use.
Ionising radiation
This is a more powerful form of energy than non-ionising radiation. It can remove an electron from an atom to change the chemical structure of a material, including DNA. This makes it potentially harmful to humans. This is why we need to manage it properly.
Sources include:
- cosmic radiation, which increases at altitude (for example travelling in a plane)
- natural materials like uranium and thorium in rocks
- naturally occurring radioactive elements in foods like bananas and brazil nuts
- medical radiation from x-rays and CT scans.
Using radioactive material
Nuclear technology uses radioactive materials that emit ionising radiation.
Researchers and medical professionals use them to improve the health of Australians through nuclear medicine. For example to:
- diagnose lung, heart, bone and muscular skeletal conditions
- treat specific types of cancers.
On average, every Australian will benefit from 2 nuclear medicine procedures during their life.
Many other industries use nuclear science, technologies and instruments:
- agriculture
- mining
- manufacturing
- environmental protection.
For example to:
- increase the quality and strength of products
- monitor and report on aspects of the environment like air quality and water sources.
Types of radioactive waste
Radioactive waste is radioactive material that has no further use. Using materials that emit ionising radiation for things like medical research results in radioactive waste.
We classify this waste into 3 categories depending on how much radiation it emits.
Low-level radioactive waste
This waste emits small amounts of radioactivity. It usually needs minimal shielding during handling, transport and storage.
Examples include gloves, gowns and clothes scientists and doctors use when producing and administering nuclear medicines.
Intermediate-level radioactive waste
This waste emits higher levels of radiation and needs extra shielding.
Examples include:
- waste from nuclear medicine production
- some of the waste from operating the OPAL nuclear research reactor in Sydney.
High-level radioactive waste
This waste contains levels of radioactivity high enough to generate significant amounts of heat during the radioactive decay process.
There is no high-level waste awaiting disposal in Australia.
Storing and disposing of radioactive waste
Australia has a responsibility to appropriately manage its radioactive waste.
- We can contain and store some low-level waste until radiation levels naturally fall under specified thresholds. We can then discard it in the same way as normal rubbish.
- Some low-level waste can remain hazardous for up to a few hundred years. We need specialised monitoring, storage and disposal methods for this type.
- Intermediate-level waste is more radioactive and can stay radioactive for much longer. We need appropriate storage and disposal methods that provide a greater level of protection and reflect longer timescales.
Australia doesn't have a central facility to store or dispose of radioactive waste. It is stored in over 100 temporary facilities across Australia. While this is currently safe it is not a permanent solution. International best practice is to consolidate radioactive waste in more appropriate facilities for the long term.
That’s why the Australian Radioactive Waste Agency (ARWA) is working to:
- understand and characterise Australia’s current and future radioactive waste
- develop a framework to manage this radioactive waste in line with international standards
- plan effective long-term management and disposal of current and future radioactive waste.
Identifying and forecasting radioactive waste
ARWA takes a national inventory of radioactive waste every 3 years to:
- help us understand the amount and type of radioactive waste in Australia
- forecast how much there will be in the future
- inform government planning and policy.
We collect information that waste holders volunteer to us.
Australia has around 5,000 cubic metres or 1,765 tonnes of radioactive waste. If visualised, this would be the size of a cube that’s 17.1m on each side.
This excludes uranium mining wastes companies have already disposed at mine sites.
In comparison, Australia generated 6.5 million tonnes (Mt) of hazardous (non-radioactive) waste in financial year 2022-23 alone.