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Energy Guide

What Is Nuclear Energy?

Nuclear energy is the energy found in the centre, or nucleus, of an atom. This energy, which binds the atom together, can be harnessed and turned into nuclear power.

How Is Nuclear Energy Produced?

Power plants produce nuclear energy by causing a nuclear chain reaction to occur. This energy is then used to heat water, or another form of cooling agent, before being used to power turbines. As these turbines turn, electricity is produced, which is then passed onto the national grid and used to power homes.

This lengthy process can be broken down into six steps:

Step 1: Triggering a reaction

The process starts in the nuclear power plant reactor vessel (RPV), which is a pressure vessel made of steel. This is where both the nuclear reaction and the release of thermal energy take place. Inside the RPV, you’ll find sealed metal cylinders, known as fuel elements or rods, that contain either uranium or plutonium. These come in the form of small nuclear fuel pellets.

Neutrons are fired at the uranium or plutonium atoms, which causes the nuclear chain reaction to begin. During this fission process, the uranium atoms split, which creates more neutrons.

These new neutrons hit other uranium atoms, and the chain reaction continues. Normally, the fuel rods are submerged in water, which moderates the speed of the reaction.

This fusion chain reaction produces a huge amount of heat energy.

Step 2: Heating the water

Inside the RPV, nuclear energy is used to heat water to over 300°C, however, it does not boil. For the energy to be harnessed, the water must stay in liquid form. To ensure that this occurs, a pressuriser is used to keep the water pressure constant at 115 times atmospheric pressure.

Once the water has reached 300°C, a coolant pump takes the heated water from the reactor core to a heat exchanger or, as it is sometimes called, a steam generator.

Step 3: Creating steam

In the steam generator, the hot water is fed through lots of small, thin, and looped pipes, which heats the exterior pipe metal. This causes the water in the steam generator to heat up. This water is not pressurised, so it eventually boils and produces steam. The steam produced is then piped to the turbine building of the power plant.

Step 4: Steam becomes electricity

Next, the heat energy is turned into mechanical energy before becoming electrical energy. In the turbine building, this steam first passes through a high-pressure turbine and sets it in motion. Next, the steam is typically fed towards two low-pressure turbines. Each of these turbines typically spins at a rate of 3,000 revs per minute!

The turbines are connected to an electricity generator by a spinning shaft, which powers the generator as it turns and produces electricity.

Step 5: Harnessing the electricity

The energy produced is harnessed and fed into a transformer, which increases the voltage before it is sent to the national grid. The grid then transmits electricity to businesses, homes, and services via power lines.

Step 6: The steam is recycled

Once the steam has been used to spin the turbines, it is cooled and turned back into liquid form. This is achieved using cooler pipes full of cold water, which the steam passes over, condensing it to water. Once this process is complete, the water is fed back into the heat exchanger, where it can be used again.

What Can Nuclear Energy Be Used For?

Is Nuclear Energy Renewable?

Nuclear energy cannot be considered to be a renewable energy source, but it can be labelled as a clean one. It is not a renewable energy source because uranium is a finite source. The specific type of uranium that is required, U-235, is also particularly rare.

The likes of wind, solar, biomass, and thermal energy sources are constantly being replenished, which is why they are considered to be renewable energy sources. This is unlike nuclear energy, as we will one day run out of U-235, and it is unlikely to replenish itself.

Some argue that uranium souced from the sea is more sustainable than mined ore uranium fuel thanks to geologic processes. Where mined ore uranium fuel is lost forever after it has been used, if properly conditioned, the water extracted from the sea could become infinite.

This would require the weathering of rocks and seawater to ensure that conditions are suitable for uranium fuel replenishment. Research and development into this possibility have been limited, mainly due to the expense associated with mining below sea level.

So, although nuclear energy cannot be considered 100% renewable currently, further research and technological advancement into deep-sea uranium mining could make nuclear energy more sustainable in the future.

Can nuclear power be recycled?

Nuclear power plants in France have taken the initiative to recycle nuclear waste to reuse it to create more electricity. One of the biggest drawbacks of nuclear power plants is the amount of waste produced after electricity has been generated.

To solve this, France separates the 4% highly radioactive waste and stores it in stainless steel canisters. The remaining 96% (95% uranium and 1% plutonium) is mixed with new uranium and used to manufacture new fuel rods.

Currently, 10% of France’s fuel resources are made up of recycled material. This approach to dealing with the nuclear waste problem brings the energy source closer to being sustainable and is a move that will surely be adopted more widely in the future.

Germany, Belgium, Russia, and Japan have also adopted nuclear recycling initiatives.

What Impact Does Nuclear Power Have on the Environment?

The Pros and Cons of Nuclear Energy


Cost-effective and efficient

The cost of setting up nuclear power plants is far from cheap. The Hickley Point C power plant in Somerset cost more than £22 billion to construct in 2019. However, once the plant is up and running, it is much cheaper to maintain than the likes of fossil fuel-fired power plants.

Plus, nuclear power plants last a lot longer than other plant types. For example, the average life span of a coal-fired power plant is 40 years, whereas a nuclear power plant can last up to 60 years.

This longevity is surprising, given that they’re constantly running at a capacity of 93% on average.

High power level

The main reason why nuclear power plants are so cheap to run is that a small amount of uranium can produce a big amount of energy. Nuclear fuel currently powers 10% of the world’s entire energy requirements, which is a massive amount considering that there are only around 440 nuclear reactors currently in use.

Does not produce any carbon emissions

The production of nuclear power does not generate any carbon emissions, unlike fossil fuel-powered plants. However, carbon and other greenhouses gasses are emitted during the extraction of uranium.

Reliable energy source

You can always rely on nuclear power. Unlike other low-carbon energy sources, such as solar, geothermal, and hydro, nuclear energy does not recure specific conditions to generate electricity. Not only is it more reliable than other clean gas options, but it is even more dependable than the likes of coal, oil, and natural gas.

Nuclear plants require less physical space

Although a nuclear power plant may appear big in scale, they take up a fraction of the land required to support wind or solar farms. This means that more land can be left to nature.

Produces jobs

Around 60,000 people currently work in the nuclear power industry in the U.K. This number is set to climb majorly as new, more advanced nuclear power plants open. There are several career options available within the nuclear power sector, including designing power plants, nuclear waste management, and uranium mining.

Career opportunities are vital as we make the move to a decarbonised future, as the number of jobs available in fossil fuel power generation will gradually reduce.


Impact on the environment

Nuclear production produces radioactive waste, both through the process of nuclear fission as well as during the extraction of uranium atoms. This waste needs to be stored within a closed facility, as it can remain active for thousands of years. Not only does storing nuclear waste take up space, but if a spillage were to occur, the results would be devasting for the nearby wildlife.

Although nuclear reactors release no carbon during nuclear fission, both mining for uranium and the construction of nuclear power plants releases CO2.


As it stands, nuclear power is non-renewable. However, through continued development in the nuclear fuel cycle, it could potentially be considered renewable one day.

Nuclear plant meltdowns

Although nuclear reactors are constantly being improved, nuclear plant disasters can still occur. The most notable core melt accident was the Chernobyl disaster of 1986, which led to the permanent evacuation of the surrounding city and an undetermined number of deaths.

More recently, the 2011 Fukushima nuclear disaster, which was the result of a major earthquake, destroyed the nuclear reactors and caused one death from radiation and several non-fatal injuries.

Requires a lot of water

Nuclear power reactors require a considerable amount of water to operate, which means that power plants need to be constructed near lakes, rivers, oceans, or other large depositories of water. Water is required during many parts of the electricity generation process. It is also required for the extraction of uranium as well as for waste control purposes.

A nuclear power plant can use as much as 2,725 litres of water in a single megawatt-hour. This is more than the likes of gas, which only requires 1,200 litres max.

The Future of Nuclear Energy

Final Thoughts

To curb climate change, nuclear power needs to be adopted alongside sustainable energy sources such as solar and wind. Nuclear-generated electricity is reliable, high-powered, and eco-friendly.

However, in switching to nuclear, we must find better ways of disposing of and recycling spent fuel. It’s also imperative to find more sustainable means of mining for fuel.

Through the building of new power plants and the further advancement of nuclear fusion, nuclear will likely become one of the U.K.’s leading energy sources in the near future.

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