Nuclear energy as a sustainable energy source?

Different countries are taking very different views on the future viability of nuclear power as an energy source. In those that generate much of their electricity from nuclear power, such as France and the Czech Republic, support for using this power for peaceful purposes is often high. By contrast, the “no” camp very clearly dominates in countries like Austria and Italy, which do not get any of their electricity from nuclear energy.

Nevertheless, accidents at nuclear power plants can change both political priorities and people’s minds. Although the Fukushima disaster prompted Germany and Switzerland to commit to phasing out nuclear technology, both countries have since repeatedly qualified the timing aspect of their objectives. The biggest problem in making an economic assessment of nuclear energy is calculating and factoring in the high external costs, also known as “externalities”.

The terms “nuclear power”, “nuclear energy”, and “atomic energy” all mean energy that is released by nuclear fission, currently the only process that is used inside a nuclear power plant. The first such plant to produce enough energy to be used industrially came on stream near Moscow in 1954, with the UK’s Sellafield following one year later. Nuclear power has been fed into the German grid since 1961 (from the Kahl nuclear power plant). Only gradually did the light-water reactors that had been favoured by the Americans from the outset win out over their heavy-water counterparts. Although the latter had been preferred by researchers, this was primarily for military applications. Whereas a light-water reactor uses normal groundwater for cooling, heavy-water technology replaces the hydrogen in the water with more massive substances (such as deuterium), thus significantly reducing the amount of uranium enrichment required. However, this benefit is partially offset by extremely high water consumption.

Nuclear power plants began to spring up in greater numbers following the 1973 oil crisis in a bid to stave off a looming energy shortage. It was around the same time that the anti-nuclear movement emerged, which really took off in 1979 following the reactor accident in the US city of Harrisburg.

Pinning hopes on nuclear fusion

Although nuclear fusion technology is still at the research stage, researchers have recently reported breakthroughs – literally within the past few months. The most promising results were achieved by a team of scientists at the government-run National Ignition Facility (NIF) research institution at the Lawrence Livermore National Laboratory in California, which mainly serves military purposes.

The researchers in California used the world’s most powerful laser for their experiments in order to transform tiny quantities of two hydrogen isotopes, deuterium and tritium, into plasma at temperatures of around 60 million degrees Celsius. The isotopes fuse into helium, losing a small portion of their mass in the form of radiation in the process. Media reports suggest that 20 per cent more energy was obtained than had been put in. Nuclear fusion is seen as a beacon of hope for the clean energy of the future as it theoretically allows a virtually unlimited amount of power to be generated in an environmentally friendly way.

The dilemma of final storage

In existing nuclear power plants, nuclear energy is converted into electrical energy in nuclear reactors using controlled nuclear fission chain reactions. The fuel elements are the most important part of the reactor’s core, as they contain the nuclear fuel that triggers the fission process.

The fuel elements have different forms and compositions depending on the reactor type, although ones made from uranium dioxide are almost always used. All types of nuclear power plant produce spent fuel elements, which can theoretically be reprocessed. If not, they have to be disposed of by being put into final storage.

Nuclear fission produces radioactive isotopes. Short-lived isotopes decay in interim storage facilities or cooling ponds. Nuclear waste containing long-lived isotopes is stored until the amount of heat it is giving off has dropped low enough for final storage to be an option – which takes a few decades.

It can be as long as thousands or even hundreds of thousands of years before the radiation from some of the radioactive waste from a nuclear power plant has largely decayed. Since some of the elements contained in nuclear waste are also highly toxic, it is stored permanently so as to be kept away from the biosphere. Storage facilities to be set up for this purpose are known as repositories. There is currently not a single repository anywhere in the world for highly radioactive waste.

The most advanced project can be found on the island of Olkiluoto in Finland (read also our article on the Finnish group Fortum), where the plan is to store highly radioactive waste in a cavern in the granite rock 400 metres underground. The waste is to be placed inside copper canisters that are themselves wrapped in the mineral bentonite, thus creating a multi-level protection system. If one of the man-made barriers were theoretically to develop a leak, the geological formations would spring into action in its place. However, the real question is whether these barriers will be able to withstand a new ice age, for instance. So far, humanity has never yet been able to build structures guaranteed to last forever.

Share of the energy mix

International Energy Agency calculations suggest that nuclear power accounts for some 10 per cent of global electricity generation at present. As of January 2023, there were 440 reactor blocks in operation in 31 countries, supplying a total capacity of 415 GW. According to the World Nuclear Association (www.world-nuclear.org), 54 reactors (with a total capacity of 59 GW) are currently under construction worldwide, mainly in China, with a further 109 being planned. EU statistics for Europe from 2019 revealed that nuclear power made up 70.58 per cent of the national energy mix in France, 33.97 per cent in Sweden, 53.86 per cent in Slovakia, and 12.36 per cent in Germany.

Pro and cons of nuclear energy

Running a nuclear power plant emits no harmful carbon dioxide and only low levels of other common air pollutants. It therefore has only a small environmental footprint compared with fossil fuels such as coal and oil, but only if incidents and accidents during operation and unforeseen events during final storage are not taken into account.

Nuclear power produces energy constantly and steadily whether or not the sun is shining or the wind is blowing, so it is seen as a stable component of baseload supply.

The technologies associated with civilian nuclear power can often be used to develop and manufacture nuclear weapons, however, opening the door for civilian nuclear energy projects to serve as cover for a clandestine military programme of nuclear weapons.

The strongest argument against the peaceful use of nuclear power is the risk of an accident, as highlighted by those at Chernobyl in 1986 and Fukushima in 2011. The abbreviation MCA stands for “maximum credible accident”, while a “super MCA” would be an accident that goes beyond the standard definition of an MCA. Environmental pollution caused by the civilian use of nuclear power arises from uranium mining and from the day-to-day operation of nuclear power plants, which does not always go smoothly.

Other counter-arguments include the unsolved question of disposal associated with final storage and the potential for making nuclear weapons (see also strict criteria for nuclear weapons). There is also the risk of terror attacks on nuclear facilities. These risks and the damage that they would cause cannot be insured due to the huge losses that could be expected (estimated at up to EUR 6 trillion). In 2011, financial mathematicians calculated that a liability insurance policy for a standard nuclear power plant would cost EUR 72 billion over its entire term. Blanket liability insurance would therefore increase current electricity prices in Germany by a factor of around 20.

Proponents of nuclear power point to the role that it plays in grid stability and the high security of supply that it offers, mainly compared with renewable energy technologies in both cases. Higher demand and the general increase in the amount of electricity required coupled with the move away from fossil fuels such as oil and gas are also fuelling the argument that nuclear power can act as a “bridging technology”. The final benefit cited is an end to reliance on oil and natural gas imports, although this argument has lost some of its force due to the shale gas and shale oil boom, particularly in the US.

The cost calculations for nuclear power do not include the “external costs”, i.e. the potential social and environmental damage caused by a nuclear disaster. Neither do they factor in damage due to uranium mining or the costs of securing sites – such as the long-term protection of decommissioned nuclear power plants and the costs for transporting waste to reprocessing facilities – or the negative impacts of interim and final storage. Yet external costs are not the only argument against building new nuclear power plants, as modern ones are also expensive to run. The only way to ensure cost-effective operation of the new reactors at Hinkley Point in the UK was via government subsidies in the form of a guaranteed purchase price for the electricity generated there.

Uranium – anything but clean

Currently, some 65,000 tonnes of uranium are extracted worldwide every year. Uranium mining is responsible for severe destruction of and damage to the environment. The greatest health risk is posed to miners in conventional mines. As uranium ore only contains a small amount of pure uranium, it is fairly harmless outside the human body. However, the mechanical process used to extract the ore from the rock exposes miners to fine particles of uranium as well as its by-product radon, a noble gas that emits radiation, in the air that they breathe. Inhaling uranium dust and radon can cause cancer, mainly lung cancer. As long ago as the 1920s, evidence showed that lung cancer in mineworkers was caused by contamination with radon.

Leaking radioactivity poses an additional health risk in parts of the world where uranium is mined, while another problem in uranium mining is the massive amount of water required. According to a Greenpeace estimate, for instance, the activity has consumed 270 billion litres of water over the past 40 years in Niger alone. This water was discharged back into rivers and seas in its contaminated state. Besides the direct health impact of water contamination, the large quantities of water consumed also causes environmental and economic damage in the regions affected. This also damages peoples’ health, because removing the water lowers the groundwater level and causes desertification. Plants and animals die, and the population’s traditional livelihoods disappear.

Having been mined extensively over the past few decades, ore deposits with a high uranium content are now largely exhausted. Instead, mining is now focusing on ores with a lower concentration, generating an increased amount of carbon emissions.

One argument against nuclear power is the availability of uranium across the world. Based on current mining activity, the reserves will last for another 20 years. By far the largest reserves that could be extracted cost-effectively at present are in Kazakhstan, followed by Canada, South Africa, Brazil, and China.

ESG assessment

E (enviroment): Key aspects from an environmental perspective are the potential radiation given off by uranium mining or radiation accidents as well as environmental risks associated with interim and final storage.

S (social): Uranium mining and incidents can damage people’s health.

G (governance): The issue of addressing or factoring in externalities remains unresolved. The possibility of the government in the country where a facility is located deciding to phase out nuclear power, especially following a nuclear accident, poses a latent risk to its operations