Giulia Cere, project manager at Hinkley Point C, explains how this sustainable source of energy works and explores the pros and cons.
Electricity plays a pivotal role in our journey to a carbon neutral future.
As this energy demand grows, we will need to find ways to produce vast amounts of it without hurting the environment.
Nuclear energy will be part of the answer, but the British public is divided on the matter. A 2024 survey found that 30% would like to see more energy from nuclear, with 30% wanting less.
At the root of that is perhaps a misunderstanding of how it works and what its advantages are.
Nuclear energy is produced by an atomic reaction called fission which creates enough steam to turn a turbine and generate electricity.
It's a stable, low-carbon energy alternative that can be directly imported into our electricity grid, so no battery storage is needed.
Nuclear power plants are carefully designed, built and operated to mitigate the risk of radioactive contamination and incidents, such as the ones at Fukushima and Chernobyl.
It all starts in the reactor, where a controlled atomic chain reaction called fission produces large amounts of heat.
Fission is when the nucleus of an atom splits into smaller pieces.
Although there are different kinds of reactors, they all operate in a similar way.
Pressurised water reactors (PWRs) are the most common. Hinkley Point C, one of the UK’s largest nuclear power plant projects, will use one of those.
The heat produced by fission is turned into steam and fed into a turbine to make it spin. The turbine’s movement is what generates electrical energy.
Nuclear technologies remain one of the top options to generate large amounts of electricity without taking up too much land.
They also secure a stable source of electricity, as they don’t depend on the weather like solar or wind power.
This makes nuclear a sustainable, low-carbon source of energy.
Moreover, electricity from nuclear plants can immediately be injected in the grid after production.
This means there’s no need for battery storage units, which contain highly polluting substances and precious, scarce metals.
As an example, Hinkley Point C alone will contribute 7% of all UK homes’ energy demand.
Nuclear energy contributes to the diversity and redundancy of the energy framework (meaning there’s more energy than we need at all times, which is crucial for resilience and security).
A negative by-product of nuclear plants is its waste, and its associated radiation.
This is normally classified into high, medium and low-level risk, depending on how much radiation there is, and the shielding or protection needed until full decay (when it is no longer radioactive).
As an example, spent fuel (created in the process of generating electricity) is high-level waste. Example of low-level waste could be tools or clothing which have been exposed to radiation.
Regardless of the level of risk, this waste is processed, stored and ultimately secured until the end of its decay time.
It is worth noting that the amount of waste generated by a plant such as Hinkley Point C is very, very small in comparison to the energy that the plant produces. New technologies will keep striving to improve this ratio.
There is also the risk of nuclear accidents.
You will probably be familiar with the Chernobyl (1986) and Fukushima (2011) nuclear accidents.
These tragic events marked a critical milestone in the nuclear industry and triggered a drastic – and necessary – shift in terms of safety culture and design.
In the case of Fukushima, it was the tsunami – not the earthquake – that exposed some design shortcomings in the plant which did not allow the operators to prevent reactor core meltdown (where the radioactive material is kept).
In particular, the sea walls around the plant had been designed with an optimistic margin for wall height and not conservative assumptions.
Similarly, the plant position was lower, bringing it closer to sea level, and the emergency generators were located in the basement.
The combination of the above and the tsunami caused an electrical blackout of the plant and the core meltdown that followed.
Nuclear power plants are often built on coasts because they need large, reliable water supplies for cooling.
Seawater is ideal because it’s abundant and doesn’t depend on seasonal river flows.
The reactor’s heat turns water into steam to drive turbines, but after use, that steam must be condensed back into water.
In a coastal plant and particularly referring to European pressurised reactors (EPRs), seawater is pumped through condensers. These absorb heat from the steam (via metal tubes) without mixing with it.
The warmed seawater is then discharged back to the sea, while the cooled water (now condensed) is recycled into the steam cycle.
There are temperature limits in place for the water that gets returned to sea in order to protect marine ecosystems.
This arrangement supports high-power output, saves freshwater resources, and ensures stable operation year-round.
Hinkley Point C features a redundant and resilient network of safeguard systems to be deployed on a manual or automated basis.
The importance of having manual safeguards was a key lesson we learned from the Fukushima disaster.
We're making the plant safe by using conservative margins when designing and applying a forward-looking design strategy that considers future conditions (for instance, the impacts of climate change).
We also feature a set of manually operated diesel-powered water pumps that can be used for fire-fighting or emergency reactor cooling. This is in case of total loss of electrical power.
The plant is also designed to withstand a large spectrum and magnitude of hazards. For example, critical areas have been designed to withstand an airplane crash.
The construction of a nuclear power plant is a complex and strictly regulated process.
First, the site must be selected and licensed through thorough geological and environmental assessments.
The project must also obtain regulatory approval. In the UK, the Office for Nuclear Regulation (ONR) is the main licensing body for nuclear facilities.
The design of a plant must begin several years ahead of its construction, unless it’s possible to ‘copy’ the design from other stations.
For example, many elements designed for Hinkley Point C can also be used on Sizewell C, the other large nuclear project in the UK.
Once construction takes place, the reactor is ready for fuel loading – that is the inserting of uranium fuel rods into the reactor core.
The plant then undergoes testing and commissioning (making it operational and verifying that it meets standards) so that it’s then ready to be put into use.
On the whole, they are expensive and take a long time to build. As such, a government must weight its options before deciding to construct a new large-scale power plant.
We need to shape the future of energy production with a pragmatic and forward-looking mindset.
Redundancy is key in energy infrastructure.
Energy production frameworks should feature a mix of different technologies of which nuclear should continue to be part of.
There are 438 usable reactors in the world, with 80 under construction.
Nuclear accounts for 8% of the total electricity generated worldwide. For comparison, renewables like wind and solar contribute 38% and natural gas 28%.
Currently, the US has the most installed nuclear capacity, followed by France then China.
China leads the way with the most new capacity under construction.
The UK has two large-scale reactors under construction, Hinkley Point C and Sizewell C.
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