Nuclear power. Is it good or bad?

Nuclear power often comes up in the discussion around how to reduce our collective carbon footprint. After all, it’s a reliable source of low-carbon energy – which is just what we’re looking for, isn’t it? Well, yes, but there are downsides. 

Like the threat from nuclear waste to the environment – and the high cost of investing in nuclear power plants. There’s a lot to it. So, in this guide, we’ll tell you all you need to know about nuclear power and take a closer look at the pros and cons.

What is nuclear energy? 

Nuclear power is made through a process called nuclear fission. It all starts with uranium – a silvery-grey metal refined from rocks or ore, and dug out of mines around the world.

Nuclear fission makes use of the energy inside refined uranium by splitting its tiny, microscopic atoms. And even though they’re tiny, these atoms have incredible power. Just look at how they compare with coal, one of our traditional, carbon-heavy sources of energy:

• 1kg of coal will create 8 kWh of power
• 1kg of uranium will create 24,000,000 kWh of power¹

That’s 2 to 3 million times more energy! All from something the weight of a bag of sugar.

How does nuclear power work? 

First, let’s go back to basics: what exactly is an atom? They’re the tiny particles that make up every object in the universe – including uranium, the substance used to generate nuclear power. 

So what’s uranium? Named after our smallest planet in the solar system, uranium is a metallic substance drawn from raw deposits of a rock called uraninite. After it’s refined, we get pure uranium – a chemical with some pretty powerful abilities to generate energy.

Nuclear fission then breaks down its tiny particles, to release the energy inside.

How does nuclear energy make electricity?

When it comes to nuclear power plants, in some ways they work just like traditional power stations. A traditional plant burns coal, oil or natural gas, using them to boil water into steam. The steam turns turbines, which drive a generator and make electricity.

Nuclear power plants follow the same process, but they don’t burn anything. Instead, they use nuclear fission to split uranium atoms inside a nuclear reactor. The energy released by this reaction heats the water, which creates steam – and then, well, you get the idea.

The big difference is the nuclear reactor, where the splitting of uranium atoms happens. Here, rods of uranium, arranged in bundles, are put into a giant water tank inside the reactor. 

When the reactor is running, high-speed particles – known as neutrons – hit the uranium atoms and split them. This releases lots of energy, as well as even more neutrons, which split other uranium atoms, triggering a chain reaction, and releasing yet more energy!

Is nuclear energy renewable?

No, nuclear energy isn’t renewable. That’s because uranium, unlike solar or wind energy, is a limited resource. So, even though there are enough uranium reserves to run the world’s reactors for 200 more years², it’s not a renewable source of energy. 

Nuclear power doesn’t produce carbon when electricity is being generated like gas or coal. But, carbon is released when building nuclear power plants – just as it is when building renewable generators. Carbon is also released when nuclear power plants are processing or transporting fuel. 

To learn more about renewable energy, and the other ways we can combat climate change, check out some of our other guides:

• How solar panels can reduce your carbon footprint
• What is "green energy" and where does it come from?
• 10 amazing facts about trees
• What is deforestation? The facts, causes, effects and solutions

Benefits of nuclear energy

Nuclear power pops up in the discussions on energy for a reason. That’s because it does have its advantages. Here are its main benefits:

• Like gas and coal, nuclear power is a consistent source of energy which is why it’s a potential answer to meeting the demand on the grid at times when there’s not enough renewable capacity. 
• It’s not technically renewable – but nuclear power has a much smaller carbon footprint than carbon-heavy fossil fuels. Nuclear energy creates around 15–50 grams of CO2 per kilowatt hour (gCO2/KWh) versus around 1,050 gCO2/KWh for coal³. 
• A uranium atom holds an incredible amount of power. Just 1kg of uranium can create 2 to 3 million times more energy than 1kg of carbon-heavy coal.

Downsides of nuclear energy

While it’s low-carbon, and wonderful at generating lots of energy, there are some downsides to nuclear energy. These include:

• The upfront cost of building nuclear power plants. This is a serious investment, and critics say it’s just not worth it, seeing as nuclear relies on a substance that will run out one day.
• Making us reliant on a handful of big power plants – unlike renewable energy, which is cheaper to build, and which we can grow by building lots of smaller energy sources.
• The risk of accidents releasing radioactive substances into the environment. Accidents aren’t common – but, for some, it’s still too risky. Lots of ordinary things give off radiation, but nuclear radiation can be highly dangerous. It’s a risk to human health, and can change the way cells in the body behave.
• The issue of nuclear waste – which comes from the processing of uranium and, ultimately, the demolition of nuclear power plant facilities.

Environmental impact of nuclear waste 

To understand the potential impact of nuclear waste on the environment, let’s look at the 3 main types, and their risk-factors:

• Low-level nuclear waste – this comes from places like hospitals, universities and research centres. In fact, it’s made wherever radioactive materials are used for x-rays and sterilising equipment, as well as in the nuclear industry. It isn’t considered high-risk. 
• Intermediate-level nuclear waste – above the upper limit of radioactivity for low-level waste, one example is the insulation and cladding used in nuclear facilities. It’s usually buried in shallow trenches in the area around a nuclear facility.
• High-level nuclear waste – this means a wide range of radioactive and unstable compounds. This type of nuclear waste – such as liquid waste from the process of reprocessing spent fuel – can give off radiation for thousands of years. As you’d expect, this type poses the greatest risk, so it needs to be disposed of very carefully. In the UK, this usually happens in a Geological Disposal Facility, where waste is buried deep underground.

Nuclear power in the UK

How many nuclear power plants are there in the UK?

The UK built its first nuclear reactor in 1956. Since then, the number of plants and reactors has grown over time – though many have been retired³. 

The UK has 7 nuclear power plants with 15 reactors:

1. Torness, Scotland

• Built: 1988
• Reactors: 2
• Capacity: 1,190 megawatts

2. Hunterston B, Scotland 

• Built: 1976
• Reactors: 2
• Capacity: 967 megawatts

3. Hartlepool, England 

• Built: 1989
• Reactors: 2
• Capacity: 1,180 megawatts

4. Heysham 1

• Built: 1989
• Reactors: 2
• Capacity: 1,155 megawatts

5. Heysham 2 

• Built: 1989
• Reactors: 2
• Capacity: 1,230 megawatts

6. Hinkley Point B 

• Built: 1976
• Reactors: 2
• Capacity: 955 megawatts

7. Dungeness B 

• Built: 1985
• Reactors: 2
• Capacity: 1,050 megawatts

How much electricity in the UK is generated with nuclear energy?

In the UK, nuclear power is used to generate a decent chunk of the electricity we use. Here are some of the key things you need to know:

• About 15% of the UK's energy came from nuclear power plants, as of January 2023⁴
• Half of the plants currently in operation are due for retirement by 2025 – but with the UK government continuing to explore future investment in nuclear power plants, it’s likely to be part of the way we generate energy for some time

As we’ve seen, nuclear has both advantages and disadvantages. On the one hand, there’s the low carbon emissions, and huge possibilities for generating energy – while on the other, there’s the high level of investment needed, and some potentially pretty serious impacts on the environment.

At OVO Energy, we’re rethinking how we use energy

Nuclear energy is a low-carbon option, but it has significant disadvantages and it's an expensive alternative to building renewable energy. It’s these energy sources that we want to support. So we’re helping customers use energy in better ways. 

Part of that is making choices that put less pressure on the grid. Like instead of doing the laundry at peak hours of the day when demand is high – doing it at times when the grid is likely to be greener, so we rely less on fossil fuels and use more renewable energy instead. 

At OVO, we believe there's a better way to do energy. That’s why we’re helping UK homes take steps to reduce their bills and our collective carbon footprint. So, whether you’re just getting started, or you’re well on your way, join us on the path to energy that’s better for you, your wallet, and the planet.

Join OVO today.

Sources and references:

1

https://www.euronuclear.org/glossary/fuel-comparison/

2

https://www.scientificamerican.com/article/how-long-will-global-uranium-deposits-last

3 

https://www.lse.ac.uk/granthaminstitute/explainers/role-nuclear-power-energy-mix-reducing-greenhouse-gas-emissions/ 

4 https://world-nuclear.org/information-library/country-profiles/countries-t-z/united-kingdom