Splitting atoms is big business in Europe, providing roughly 24% of the electricity generated in the first half of 2024 for the European Union. Utilising the laws of physics, we are able to take atoms and split them to release enormous amounts of energy that can be harnessed into electricity.
This process has a bright side and a dark side. The advent of this technological breakthrough in the early 1940s is also what brought us the atomic bomb. But with nuclear energy, we are talking about controlled releases of the energy of atoms to boil water and spin a turbine with pressurised steam. This is the same thing we do when we burn fossil fuels to generate electricity, only nuclear energy does not emit carbon dioxide or other greenhouse gases while operating.
Nonetheless, nuclear energy has been around for less than a century and most people have a hard time understanding what it is, how it works, where it comes from and what all the fuss about it is. This article will help you answer all these questions and more.
The history of nuclear power: it all starts with big bangs
If we are really to look back at the history of nuclear energy, you need to go back to about 100 million years after the Big Bang, when the first stars were forming. These stars press particles together with such force that they begin to fuse into single particles, a process known as nuclear reaction fusion. For billions of years, this would have been the only nuclear power one would speak of. It is only recently that we can talk about nuclear power that has been harnessed by humanity.
Humanity’s big bang
Humans started harnessing the power of the atom less than 100 years ago. In 1932, Ernest Walton – Irish physics and winner of the Nobel Physics Prize in 1951 – split the atom for the first time, a process known as nuclear fission. Many of the world’s greatest minds understood that with the amounts of energy released from a single atom, very little fuel would be needed for a really big bang. So did governments who were on a war footing. This triggered a global race for a weapon with massive destruction potential.
In the United States, this race culminated in the top-secret Manhattan Project during World War II to develop the world’s first atom bomb. A stepping stone to getting there, however, was to sustain an artificial nuclear chain reaction. On 2 December 1942, Chicago Pile-1 (CP-1) became the first nuclear fission reactor to sustain a chain reaction under the lead of Enrico Fermi – Italian-American Scientist and Nobel Prize for Physics in 1938 – at the University of Chicago. This was the dawn of the nuclear age.
The Atomic Age
Following the completion of the Manhattan Project, nuclear arms remained the focus of innovation for about a decade. It was only in 1954 that the Soviet Union created the first grid-connected nuclear power station with a fission reactor named Atom Mirny-1 (AM-1) or Peaceful Atom-1 in English.
The December before, the President of the United States, Dwight D. Eisenhower, had given a speech known today as the Atoms for Peace speech:
“The United States knows that peaceful power from atomic energy is no dream of the future. The capability, already proved, is here today. Who can doubt that, if the entire body of the world’s scientists and engineers had adequate amounts of fissionable material with which to test and develop their ideas, this capability would rapidly be transformed into universal, efficient and economic usage?”
Although broadly propagandistic to shift attention away from the countries bourgeoning nuclear arms program, it laid sights on the positive potential of nuclear science. This is where the nuclear age takes on two separate timelines – one about arms and the other about power plants. We are focusing on the energy timeline in this article.
Nuclear power’s rise and fall
From about 5 MW of capacity in the first nuclear reactor to today, nuclear power has come a long way. According to Ember’s data, it took about a decade from there to reach 25 terrawatt-hours (TWh) of electricity production which then tripled in 1970. From this date until 1990, the world entered the nuclear power golden age as generation reached 2,000 TWh in 1990. From then on, additional generation slowed.
The highest share of nuclear power in the global energy mix came in 1996 when it reached 17.44%. From then on, generation plateaued while its share in the energy mix declined. Today it accounts for just 9.11% of global energy production. What happened?
Three events have punctuated the rise and fall of nuclear power’s growth. First, in 1979 a reactor at the Three Mile Island nuclear facility in the US began to leak radioactive gas. This accident lead to heightened concern over and opposition to nuclear power.
Then in 1986 a complete failure of the Chernobyl nuclear power plant led to an explosion of a nuclear reactor and permanent abandonment of the community of Pripyat nearby in the Soviet Union, today Ukraine. Chernobyl had serious repercussions as radiation from the accident was detected across Europe for years and led to a strong anti-nuclear backlash across the world leading to a slowdown in the technology’s use in the decades to come.
Following the Chernobyl disaster, Italy held a referendum on the technology and voted in favour of phasing out their nuclear fleet in 1987. Similarly, Germany decided to end the use of nuclear energy, this decision was later reversed until another nuclear accident occurred in 2011.
A tsunami in Japan led to grid failure in which the Fukushima Daiichi nuclear power plant unit lost power and the ability to cool its reactors resulting in a leak of radioactive contaminants. This was the final straw for Germany, who recommitted to phasing out nuclear energy, and in 2023, switched off its last three nuclear power plants.
Nuclear’s renaissance?
Despite these events, several countries, including in Europe, still rely heavily on nuclear power for their production of electricity. Today too, there is cautious optimism for the future of the nuclear industry given its low carbon footprint and potential in reaching net zero.
New generations of reactors including small and advanced modular reactors (SMRs and AMRs, respectively), seek to address safety concerns from past disasters while delivering new benefits that could help revitalise the sector. Hence we arrive at the end of nuclear’s history and the beginning of its future.
The power of splitting the atom: how nuclear works
Thus far, we have understood that we can split or combine atoms to produce energy, but we haven’t understood why. These two sources of energy come down to a physics equation that you have likely heard of: e=mc2or energy is equal to mass times the universal constant squared.
Without going into the specifics of Albert Einstein’s brainchild, what you need to understand is that when changing the mass of something – by combining or splitting an atom, for example – energy must proportionally change with the mass. Using this idea, we can then harness the power of the atom for our own uses. Here’s how.
What is nuclear fission?
When using nuclear fission to generate electricity, we are using the same thermal generation process of gas, coal or other fossil fuel technologies, which boils water to create pressurised steam that spins a turbine. Unlike with oil and gas, however, nuclear does not burn a fuel but rather uses it to creates a chain reaction of atom splitting which releases enormous amounts of thermal energy to boil water and spin the turbine.
A nuclear chain reaction is ignited by ramming a neutron into an atom of nuclear fuel, also known as fissile material, which is usually a radioactive isotope of uranium known as uranium-235. This fissile material is unstable and therefore is easy to split, but also is not abundant in nature, so it needs to be enriched from uranium in its more stable form, uranium-238. To be able to sustain a chain reaction for power generation, uranium needs to be enriched to about 3-5% which is considered low-enriched uranium (LEU) and then processed into nuclear fuel. Note, this is far below the 80-85% threshold in highly enriched uranium (HEU) used for nuclear weapons.
The chain reaction referred to in fission is simply the fact that, as an atom splits, it sends particles like neutrons flying in all directions – also known as nuclear radiation. Within a controlled space, these particles can then run into other atoms of the fissile material, splitting more atoms and so on. This process begins to release thermal energy as a biproduct which is used to boil water, pressurising steam within valves that is used to spin a turbine. This is why nuclear energy is considered thermal energy.
To slow or stop the chain reaction from getting out of hand, there is also control rods in the reactor that can be taken out or added depending on the need to increase or decrease power generation or stop the reaction altogether. These rods are made up of a non-fissile material like graphite, which absorbs the nuclear radiation from the chain reaction and brings it back to stasis. Run this way, a traditional nuclear reactor can run 12-18 months on a single refuel, making it extremely efficient.
What is nuclear fusion?
As discussed earlier, stars run on the natural process of combining atoms to create energy. Hypothetically, this reaction can be recreated on Earth by humans too, which could result in a near limitless amount of energy generation. The process development is complex and scientists are still working out the best way to do it in order to generate electricity, but here it is in a very simple nutshell.
A fusion reactor would first need to create an environment where the fuel for the reaction could be fused. In this case, a super-heated plasma needs to be created reaching hundreds of millions of degrees Celsius and it needs to be under enormous pressure. This plasma is by all means a miniature start and thus needs to be contained both to preserve the surrounding environment and to continue the reaction.
Once this plasma is created, it can be fed with fuel such as the two isotopes of hydrogen, as deuterium or tritium. In this plasma, the atoms move so fast that they collide and fuse, ejecting a neutron and energy. This energy would then be used in the same way we use the thermal energy of fission to boil water to create pressurised steam and turn a turbine.
Today, scientists are operating several experiments to harness this power for humanity, but it is only in the early development stages. Only in 2022 have they managed to create a net energy gain in which more energy was released than the amount put in to create the fusion reaction. However, hurdles remain and a grid-connected fusion reactor is a long ways off. So for today, our nuclear energy needs are fulfilled entirely by nuclear fission.
The nuclear debate
The term “nuclear energy” often comes with a visceral reaction making one either a proponent or opponent. The reality should be less polarised however. While there are some difficult issues to address, there are also a number of positive contributions that nuclear energy provides the world. Let’s now look at the arguments for and against nuclear power.
The cons of nuclear
Arguments against nuclear energy often come in four forms:
- It is dangerous.
- We don’t know what to do with the radioactive waste.
- It creates a risk of nuclear arms proliferation.
- It costs billions.
Safety
Safety is probably the biggest concern cited by opponents of nuclear energy and they do not need to look hard to find examples. See above. What is important to note, however, is that nuclear design has come a long way since the days of Chernobyl and Three Mile Island.
Safety has been superimposed and the types of failures experienced in those plants cannot happen today. What is more, the botched crisis management of the Chernobyl disaster was a direct result of the corrupt regime that defined the Soviet Union and points to clear regulation and policy as a solution. With Fukushima as well, ample warning was given about the siting of the power station unit and its ability to withstand the exact event that took place. Disaster avoidance therefore depends on proper protocol, regulation and oversight.
Waste
Waste is another concern for nuclear opponents. Spent nuclear fuel is radioactive, meaning it poses a health risk to life. Proper and permanent waste disposal is difficult, especially due to the fact that the fuel remains radioactive for tens of thousands of years. It is extremely challenging to find a location that can remain secure for such expanses of time, and to communicate to any future generations what is contained within the disposal site.
Notable however, is that due to the high efficiency of nuclear reactors, the total amount of nuclear waste in the US today would fit inside a single football stadium confirms the US Department of Energy. Furthermore, new designs of reactors are finding ways to utilise spent fissile material for a second time, reducing the radioactive half-life of the material by thousands of years.
Some efforts to overcome the waste disposal challenge are also underway. In Finland, the Onkalo spent nuclear fuel repository has become the first final construction unit for spent nuclear fuel. More work however must still be done to respond to this issue and requires attention by policymakers and the energy sector.
Nuclear proliferation
A third valid concern is the risk or nuclear arms proliferation. The process to enrich uranium for nuclear power is the same for nuclear weapons. To ensure that nuclear weapons are not proliferated, regular checks on enrichment sites are necessary to determine to what level uranium is being enriched. As mentioned earlier, most nuclear reactors need only 3-5% LEU for fission.
Newer technologies like SMRs may use 5-20% high-assay LEU or HALEU but weapons grade uranium or HEU is 80-85% enriched. This takes much more time to do and is easily monitored by global authorities such as the International Atomic Energy Agency (IAEA). The important point here is to ensure that international monitoring is allowed to take place to ensure enriched uranium is accounted for and does not pass the weapons-grade threshold.
Costs
Cost is a final concern for nuclear opponents that has historical backing. Nuclear projects tend to go over budget and over time during construction leading to even greater costs. Expenses have ballooned with increased safety regulations that have been implemented since the heyday of nuclear energy. This calls for the standardisation and harmonisation of nuclear projects.
SMRs specifically can rise to the challenge. Instead of bespoke reactors of massive capacity as we have seen to date (around 1 gigawatt per site), SMRs would be smaller and modular plants, accounting for about 50 MW of capacity each. They would be mass produced in serial succession to leverage potential economies of scale to drive down costs. Standardised original equipment for such reactors and harmonisation of regulations would also help drive down costs by making nuclear power a competitive marketplace. Nonetheless, commercialisation of SMRs is still years out and in terms of cost-benefit, investment in nuclear is a tough cost to shoulder.
The pros for nuclear
There are nonetheless reasons to keep nuclear in the energy mix and continue to innovate for the future of the sector. These include the enormous potential as a clean zero-emissions baseload of electricity, the potential to provide energy independence and massive economic benefits in terms of jobs and industry.
Zero Emissions
Clean baseload is a key reason for nuclear to remaining in the energy mix of the future. With massive generation potential that does not rely on combustion, the energy generated by nuclear power stations is emission-free. Nuclear thus contributes to Europe’s climate ambition and net-zero target by 2050.
Firm dispatchable capacity
Furthermore, as the energy transition continues and we add massive amounts of variable renewable energy sources to the energy mix, nuclear power plants production remain constant and can thus serve as a valuable base for when the wind doesn’t blow and the sun doesn’t shine. However, there is also an argument to be made that nuclear reactors are hard to ramp up and down, taking days to adjust to fluctuations.
Due to their massive capital costs, they need to be run quite steadily at high capacity to make them economically viable which can result in a dilemma as to how much nuclear to renewables is needed in the energy mix to provide affordable electricity when needed, making it a key discussion for energy security.
Energy independence
Energy security is another argument in favour of nuclear energy. It a way to diversify away from imported oil and gas, both reducing their carbon footprint and enabling the country to meet energy needs with more sovereignty. This is amplified by the fact that a low amount of nuclear fuel is needed for a large output, making it an energy efficient choice as well.
Nonetheless, not all countries are endowed with uranium deposits, nor do they all have the means to enrich and process it into fissile material. It also takes a long time from planning to commissioning a nuclear power plant so in terms of meeting immediate energy security challenges, nuclear is not always the right answer for every country.
Economic benefits
These include high-quality jobs, stimulus for nearby communities and even residual benefits for industry. Being a highly technical technology, nuclear energy employs many high-skilled workers, creating good jobs that lead to an economic stimulus effect of surrounding communities. Further development of the technology would only grow these opportunities making the case for continued innovation and programs to support advanced reactor developments.
What is more, the local industry can benefit from nuclear reactors’ waste heat, incorporating it into process heat for manufacturing. Another runoff industry could be the use of excess electricity from the baseload generator to be diverted for either hydrogen production – a process known as electrolysis – or for power storage. This concept though is in its infancy and considering the current questionable viability of hydrogen projects would not be ideal in today’s market.
Nuclear energy’s place in Europe, today and tomorrow
Given the pros and cons, what place does nuclear energy have in Europe’s energy mix today? Despite decline in recent decades, nuclear power still makes up a significant share of electricity generation, accounting for a quarter of all electricity generated – the single most by any single technology in the EU, as shown by Eurelectric’s electricity data platform ELDA.
This varies by country, of course. Germany has phased out all nuclear units as has Italy and Lithuania, while Austria, Cyprus, Denmark, Estonia, Greece, Ireland, Latvia, Luxembourg, Malta, Poland and Portugal have never generated their own electricity with nuclear power.
Meanwhile, according to Elda, as of July 2024, France is the largest producer of nuclear energy in the EU accounting for nearly 70% of their electricity generation which is sold across borders, including non-nuclear Germany and Italy.
Belgium, Spain, Sweden and Finland are considered the other big nuclear countries in the EU while Bulgaria, Czechia, Hungary, Netherlands, Romania, Slovakia and Slovenia also have nuclear power units. Croatia also benefits from co-ownership of the Krško Nuclear Power Plant in Slovenia while Poland is planning to become a nuclear country in the future.
The Polish example is a telling one as the country is known for its historical dependence on polluting coal for power production. To overcome such dependence, diversity its energy mix and abate emissions, Poland is targeting the construction of the first nuclear power plant unit by 2033. After that, further units will be commissioned and begin construction in the next two to three years to reach a total of six nuclear reactors.
Much like France exporting nuclear generation to Germany, many non-nuclear countries nonetheless benefit from the generation of their neighbours’ nuclear such as Italy which is one of the main importers of French nuclear power. It could therefore also be argued that there is no EU country that does not use nuclear power be it directly or indirectly.
All this is to say that the EU is relatively split on the use of nuclear energy, but it is nonetheless an indispensable technology that contributes to clean electricity in the EU.
What is the EU doing on nuclear power?
Looking ahead, the European Commission has recognised that nuclear technology will play a vital role in a competitive energy mix across the EU and is seeking to promote innovation in the sector. Specifically, with SMRs, the European Commission established a European Industrial Alliance on Small Modular Reactors in February 2024 to accelerate the development, design, demonstration, and construction of the technology in the EU by the early 2030s.
Eurelectric called for a holistic EU-wide approach to SMRs in November 2023 and enthusiastically joined the Alliance. The Commission emphasised at the first meeting of the Alliance in May 2024 that the examples and technologies shared in the Alliance will not just be theoretical. The Alliance is to be an operational-level platform focused on what can be deployed today.
Going beyond SMRs, POLITICO reported last week that the Commission will likely come up with a “Nuclear Act” that could be proposed by the end of this year to support nuclear power development and help businesses decarbonise in the most competitive way while aligning with Europe’s net zero ambition.
As believers of a technology-neutral approach to decarbonised energy sources, Eurelectric welcomes the news and looks forward to advising the Commission.
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Disclaimer: This article is for informative purposes only and may not entirely reflect Eurelectric official positions. For formal positions, please consult our position papers here.