Key facts
Nuclear power produces a lot of energy from nuclear fuel in a controllable and reliable reaction.
Nuclear fuel is a finite resourceResource聽that聽is in limited supply. It聽will eventually run out due to us using it. so it is not a renewable Something that does not run out when used. source of energy.
It does not produce carbon dioxide or other greenhouse gases, so it does not contribute directly to global heating. Some people consider it is a good alternative to non-renewableNatural resources that cannot be replaced after they are used. This means that they exist in a fixed amount on Earth. Fossil fuels such as coal, oil and gas are all non-renewable resources. fossil fuels.
Radiation from nuclear fuel and nuclear waste can be very harmful to living things, so some people think that nuclear fuel is too big a threat to health and the environment to use.
Nuclear energy and its impact
How nuclear power is generated
Nuclear power stations are similar to traditional power plants because water is heated to turn turbineA turbine is a machine that turns the movement of liquid or gas into energy that can be used. In a simple turbine water or air push against turbine blades and spin them round. The spinning blades turn a long pole called a shaft. The shaft can then turn other pieces of machinery, such as a generator that is used to produce electricity. and generate electrical energy.
However, instead of burning fuels, the uranium atoms (the nuclear fuel) undergo a reaction called nuclear fission which creates the heat.
Nuclear fission
Nuclear fission is when an atomTiny particles that everything in the universe is made from. Different atoms make up different materials, called elements. is split by firing a neutron (very small particle) at it. Splitting an atom releases a large amount of energy in the form of heat.
Nuclear reactors
The main nuclear fuels are uranium and plutonium. These are housed in a nuclear reactor.
- The nuclear fuel undergoes nuclear fission in the reactor, producing heat - nuclear to heat energy.
- Heat is used to change water into steam in the heat exchanger
- The steam drives the turbine - heat to kinetic energy
- This drives the generator to produce electricity - kinetic to electrical energy
Location factors
Nuclear power stations need a reliable source of water for cooling and other purposes. They are most often built next to the sea or large lakes.
Radiation can be very harmful to any living thing, including people. For this reason nuclear power stations are located in areas away from towns and cities.
Accidents at nuclear power stations can have devastating results, so they need to be built away from risks of damage by flooding, earthquakes or extreme weather. In 2011, a tsunamiA giant sea wave caused by an underwater earthquake, volcanic eruption or a landslide into the sea. caused a power failure at the Fukushima nuclear power station in Japan. This caused the reactor to overheat, causing a series of explosions and the release of huge amounts of radiation.
Sustainability of nuclear energy
To develop a sustainable future you need to think about meeting today's needs and protecting the聽environment听补苍诲听resources聽for the future.
Nuclear power is non-renewable because there is only a finite amount of nuclear fuel in the world. However, only small amounts of nuclear fuel are needed to produce large amounts of energy, so it is not used up as quickly as fossil fuels.
Nuclear power is sustainable in that it does not release greenhouse gases and contribute to global heating. It does release small amounts of radioactive gas and other material but only at very low doses.
It does leave behind nuclear waste which is more radioactive and which needs to be stored deep underground for safety and security.
Advantages and disadvantages of nuclear energy
Advantages
- Nuclear power is cleaner than fossil fuels (greenhouse gasA gas that absorbs heat so that it is trapped in the Earth's atmosphere. Greenhouse gases help keep the Earth warm but increasing amounts of greenhouse gases causes global heating. The main greenhouse gases are water vapour, carbon dioxide and methane such as carbon dioxide or sulphur dioxide are not produced)
- It is very efficient - only a small mass of nuclear fuel is required to generate lots of electricity.
- Although nuclear fuel is non-renewableNatural resources that cannot be replaced after they are used. This means that they exist in a fixed amount on Earth. Fossil fuels such as coal, oil and gas are all non-renewable resources. it is not used up quickly.
- Once set up, running costs are low.
Disadvantages
- Nuclear fuel is non-renewable and will run out eventually
- The cost of set up is very high and so a large amount of money is required initially. The process is takes many years.
- Decommissioning nuclear power stations so they are not an environmental or health threat when no longer in use is also a long and expensive process.
- Some nuclear waste is highly radioactive and must be disposed of carefully. It is usually buried deep underground
- Any accidents can release radiation which is potentially harmful to people and the environment.
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