Coaching Centre
Uranium and nuclear energy
Uranium as a non-renewable energy resource, Australia's uranium mines, nuclear fission and chain reactions, how a nuclear power station works, control rods, radiation, radioactive waste, Fukushima, and the debate about nuclear power in Australia.
A uranium fuel pellet is about the size of the tip of your little finger. Inside a nuclear reactor, that one pellet releases about as much energy as a tonne of black coal, with almost no carbon dioxide. Australia has more uranium than any other country, yet it's against the law to build a nuclear power station here. Science can tell us what nuclear power does; deciding whether to use it is a question for everyone.
Uranium in Australia
Uranium is a heavy, slightly radioactive metal found in rocks of the lithosphere. Like coal, it is non-renewable: there is a fixed amount, formed when the Earth itself formed. Australia holds about a quarter to a third of the world's known uranium resources, more than any other country.
- Olympic Dam in South Australia is the largest known uranium deposit in the world. It is also a huge copper mine.
- Other mines in South Australia, such as Four Mile and Honeymoon, dissolve the uranium out of the rock underground and pump the solution to the surface.
- The Ranger mine, surrounded by Kakadu National Park in the Northern Territory, operated for about 40 years. It closed in 2021 and is being rehabilitated. The Mirarr people, the Traditional Owners, had long opposed mining on their Country, and successfully stopped the nearby Jabiluka mine.
Almost all Australian uranium is exported to countries that use nuclear power, under strict agreements that it is used only for electricity and not weapons. The only nuclear reactor in Australia is the OPAL research reactor at Lucas Heights in southern Sydney, which makes medicines used to diagnose and treat cancer.
Splitting atoms
Nuclear power uses nuclear fission, the splitting of the nucleus (centre) of an atom. When a tiny particle called a neutron hits the nucleus of a uranium-235 atom, the nucleus splits into two smaller nuclei, gives off a large amount of energy as heat, and releases two or three new neutrons.
Those new neutrons can hit more uranium nuclei, which release more neutrons, which split more nuclei. This is a chain reaction. Left uncontrolled, it would release energy faster and faster. In a reactor, control rods made of materials that absorb neutrons are moved in and out to keep it steady.
- With the rods half in, fire a neutron. How many atoms split?
- Push the rods all the way in and try again. Then pull them all the way out (reload the fuel each time).
- What setting would a power station operator want? Why?
A nuclear power station
A nuclear power station is a lot like a coal-fired one. The difference is where the heat comes from. Heat from fission in the reactor boils water into steam; the steam spins turbines, which turn generators. The energy changes are nuclear → heat → kinetic → electrical. Once built, it produces very little carbon dioxide, and it runs day and night regardless of the weather.
About 9% of the world's electricity comes from nuclear power. France gets around two-thirds of its electricity this way, and the USA and China have the most reactors.
Radiation, waste and accidents
Fission produces radioactive waste. It gives off radiation that can damage the DNA inside cells, causing cancer and other illnesses, and some of it stays dangerous for thousands of years. It must be stored securely, sealed off from people and groundwater. Finland has built the world's first permanent deep underground store, 400 metres down in solid rock.
Accidents are rare but serious. In 2011, an earthquake and tsunami knocked out the cooling system at the Fukushima power station in Japan. Three reactors overheated and radioactive material leaked, and about 150 000 people had to leave their homes.
Should Australia use nuclear power?
Nuclear power stations have been banned in Australia by federal law since 1998. Nuclear power was a major issue at the 2025 federal election, when one side proposed building seven nuclear power stations; the ban remains. People disagree because they weigh different things:
| Arguments for | Arguments against |
|---|---|
| Very little CO₂ once running | Radioactive waste lasts thousands of years |
| Runs 24 hours a day in any weather | Rare but severe accidents |
| Huge amounts of energy from little fuel | Very expensive and slow to build (often 10–15 years) |
| Australia has plenty of uranium | Solar, wind and batteries are now cheaper and faster to build |
Test yourself
Nuclear fission is
A neutron splits the uranium-235 nucleus.
Control rods in a reactor work by
Fewer neutrons means fewer splits.
How is a nuclear power station similar to a coal-fired one?
Only the heat source is different.
Radiation is harmful to living things mainly because it
Damaged DNA can lead to cancer.
Most uranium mined in Australia is
Australia has no nuclear power stations.
Label nuclear fission.
Sort the arguments.
A splits a uranium-235 nucleus, releasing heat and more neutrons. This can set off a reaction. Control keep it steady. Uranium is a resource.
Compare a nuclear power station with a coal-fired power station. Include one similarity and two differences.
Both types of power station use heat to boil water into steam, which spins turbines that turn generators to make electricity. One difference is the source of heat: a coal station burns coal, while a nuclear station splits uranium-235 atoms by fission. A second difference is the waste: burning coal releases large amounts of carbon dioxide, which adds to the enhanced greenhouse effect, while a nuclear station releases almost no CO₂ but produces radioactive waste that must be stored safely for thousands of years.