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The world is in a state of emergency and major scientific and energy studies include nuclear energy in the path towards achieving climate neutrality by 2050.
For example, the "Future of Nuclear Energy in a Low-Carbon Environment" report by Citi GPS affirms that this energy is a key component in the energy transition because it is a controllable source of electricity with low carbon emissions.
With this in mind, nuclear energy has been included in the European Union Taxonomy as an environmentally sustainable economic activity and during COP 28 (Dubai, 2023), 22 countries signed an agreement acknowledging the key role of nuclear energy in achieving net zero emissions by 2050 and committing to tripling nuclear production by 2050.
As it is a source with a reduced climate impact, the question arises as to whether we can talk about nuclear energy as a renewable resource. To find the answer, you need to know how it is generated and if it is an unlimited resource.
How is nuclear energy generated?
Nuclear energy is produced by the fission of uranium atoms, a process that releases heat to generate steam and, consequently, electricity. This form of generation makes it possible to provide electricity 24 hours a day without emitting greenhouse gases.
Uranium, the necessary raw material, is an abundant metal in its natural state with reserves that will last for so many years that it is virtually inexhaustible. This is what appears in the 28th edition of the Uranium Red Book, prepared jointly by the OECD Nuclear Energy Agency and the United Nations International Atomic Energy Agency:
"Reserves are sufficient to meet the demand. Not including any new uranium ore reserves that may discovered, there is enough uranium for the next 120 years."
It can also be safely and easily stored and it is being mined in numerous countries. This diversity of origins, together with its energy density and the ability to store it safely (it is possible to store enough of the raw material for the generation of energy for several years in small spaces), make nuclear energy a key source for generation because there is security of supply and energy independence, by eliminating dependence on unstable countries and protecting the supply from one-off crises.
Why is nuclear power controversial?
Nuclear energy is a clean energy source that does not pollute. So, what are we arguing about?
Nuclear power plants have high operating safety standards and a high degree of supervision by both national bodies (the Nuclear Safety Council is the main Spanish regulator) and international bodies.
The WANO (World Association of Nuclear Operators) Performance Indicators Programme supports the exchange of operational experiences by collecting data on the performance of nuclear plants with regard to safety and reliability, and according to these indicators, Spanish nuclear power plants are among the most reliable and secure.
Nuclear waste
The energy density of nuclear fuel is extremely high compared to other fuels, which means that nuclear fuel can store or release a greater amount of energy per unit mass or volume compared to other fuels. This is because the higher the energy density, the greater the amount of energy that is stored.
This means that the volume of fuel used, and therefore the amount of high-level waste generated, is minimal compared to the energy it generates. In this way, the volume of waste that Spanish power plants would have generated and would generate, in the event of reaching the dates foreseen in the National Integrated Energy and Climate Plan (PNIEC) would be approximately 11,400m3, which is equivalent to approximately 3.4 Olympic swimming pools.
In technical terms, nuclear waste is classified according to its level of activity and half-life, which makes it possible to design specific strategies for its management. There are technical solutions for the management of all nuclear waste generated in the operation and dismantling of nuclear power plants:
- High-activity, long-life waste is kept in Deep Geological Storage (DGS). The most advanced country with regard to this solution is Finland, which is finalising the construction of a Deep Geological Storage, called Onkalo, and which will begin to receive the first nuclear waste in 2025.
- Low- and medium-level waste is generally stored in surface storage facilities, such as El Cabril, which is the low- and medium-level radioactive waste storage facility managed by Enresa in Spain.
In addition to storage methods, technologies have been developed for the processing and reprocessing of nuclear waste, in order to reduce its volume and toxicity, as well as to recover valuable materials for reuse such as nuclear fuel, increasing the energy yield of the fuel.
This can be done with the so-called fast reactors, with experience in operation in a number of countries (France, Japan, Russia, etc.), which make it possible to take advantage of the energy content of the irradiated fuel, going from 5% of the energy content for the current reactors in Spain, to 95%, which would increase the existing reserves to turn nuclear fuel into an almost infinite source.
Benefits of Nuclear Power
In this scenario, nuclear energy continues to be proposed as an energy source that provides significant benefits in the current situation, of which the following deserve special mention:
- Security of supply and energy independence: Significant natural reserves, diversity of origins, together with energy density and the ability to be stored safely, make nuclear energy a key source of generation for security of supply and energy independence.
- Stable prices: As reflected in the 2022 opinion of the European Economic and Social Committee on 'The role of nuclear energy in energy price stability in the EU'. The costs of nuclear energy are fixed and lower than those of gas and coal power plants, which are subject to high volatility due to the costs related to gas supply and their CO₂ emissions.
- Reliable energy potential: Nuclear power plants produce a large amount of energy without making use of large tracts of land. Supply is also constant and does not depend on the availability of the resource.
- It benefits the environment: Nuclear is clean in terms of emissions. A nuclear power plant does not emit greenhouse gases or other combustion products such as ash that accelerate climate change.
How many nuclear power plants are there in Spain? And in the world?
According to the Ministry of Ecological Transition and the Demographic Challenge, there are 412 nuclear power plants in operation worldwide, of which 5 are located in Spain. However, the Spanish government's plan is different from that of other countries.
These seven nuclear reactors prevent the emission into the atmosphere of more than 30 million tons of CO₂ each year and produce more than 35% of electricity that is emission-free.
In the world, there are 246 reactors that have been in operation for over 35 years, and of these 191 are authorised to operate for more than 40 years.
In Western countries, the period of validity for operating licences for nuclear reactors is being extended. The most paradigmatic case is that of the United States, with 90 reactors with a 60-year operating licence, and of these almost all have requested a new licence extension to 80 years (8 reactors have already had it approved), and the possibility of extending it to 100 years is being technically analysed.
Similarly, France, with 56 reactors in operation, is in the process of extending their operating license to 60 years, and Sweden, Switzerland, Belgium and the Netherlands, among other countries, are also in the process of extending the life of their nuclear power plants.
Taking into account the need to electrify demand with zero-emission technologies, there is a worldwide push for as much electricity generation capacity as possible, both renewable and nuclear.
This is why they are not only extending the operational life of the plants, but many countries are investing in the construction of new power stations. According to the World Nuclear Association, there are 60 reactors under construction (in the United Kingdom, France, Finland, Sweden, the United States, Canada, China, Russia, etc.), which will be joined in the medium term by a large part of the more than 110 planned reactors.
This estimate for "traditional" or large-scale nuclear reactors will be complemented with Small Modular Reactors (SMRs), which are reactors generating less than 300MW that are currently being designed and licenced and are expected to be commercially implemented in the next decade.
In addition to their small size, which involves a lower construction cost, these SMRs will have other advantages: Standardisation of manufacturing and construction, lower water use requirements, greater capacities to adapt to any site and the replacement of energy sources being abandoned (such as coal) and greater adaptability for other uses (e.g. water desalination, hydrogen production, industrial use, etc.)
Nuclear energy plays a crucial role as a clean source in the energy transition. Its capacity to generate electricity safely, consistently and reliably without greenhouse gas emissions makes it an attractive alternative to supplement renewable energies.