Article
Article
06.01.21
While most people have accepted the need to decarbonise to avoid a climate disaster, opinions continue to diverge on what path to take to our carbon-free future. In particular, the role of nuclear power continues to be a topic of fierce debate, and nowhere is that debate more aggressive than in Europe. Many environmentalists recognise that nuclear (which along with hydro is one of the two largest sources of zero-carbon electricity) is critical to deep decarbonisation. Understanding this, countries like the UK, Poland, and Hungary have positioned nuclear as vital to their zero-carbon goals. Elsewhere in the world, governments are doing the same — China has 18 GWe of nuclear under construction, the United States and Canada are both investing heavily in new nuclear technologies and the UAE just brought its first reactor – part of a 5.6 GWe plant – into operation. Meanwhile, Germany is continuing to phase out nuclear power despite a resulting rise in carbon emissions, and Austria has sworn to oppose any expansion of nuclear power in Europe. Which side is right?
Those opposing nuclear frequently cite safety and waste as two primary reasons to exclude it from the energy mix. Both issues trigger emotional responses and have been driving both politics and public opinion for decades, but should such a climate-critical decision be made with the heart or the head?
The events at Chernobyl and Fukushima Daiichi understandably dominate the discussion regarding nuclear power, but these two accidents are very much outliers in the six decades since the advent of nuclear. The early Soviet-designed reactors of the type that operated at Chernobyl were shut down in Bulgaria, Slovakia and Lithuania as a condition of those countries’ accession to the European Union. Further, Chernobyl resulted in the adoption of higher standards and mechanisms globally to enhance nuclear safety and emergency preparedness and response. While Fukushima caused no injuries or deaths from radiation exposure, the event nevertheless resulted in a complete overhaul of Japan’s nuclear regulator and Japan has come to the rational decision to restart its nuclear fleet. Post Fukushima, every European country operating nuclear plants successfully carried out safety stress tests – demonstrating that a Fukushima-type incident would not occur in Europe. Today’s European nuclear power plants operate in accordance with the highest safety standards. In fact, the Joint Research Centre (JRC), the EU’s scientific body, concluded earlier this year that there is no “science-based evidence that nuclear energy does more harm to human health or to the environment” than other zero-carbon electricity production technologies such as renewables. To top this, the next generation of advanced nuclear reactors are designed to be “walkaway safe”, making a nuclear incident close to an impossibility.
The question of waste is more one of politics than science or technology. The “waste” at the centre of the nuclear debate is spent nuclear fuel. Given the massive energy output of the nuclear fission process, the volume of waste is almost negligible, and several decades-worth of fuel fits into a pool not much bigger than you would find at your local lido. Importantly, that fuel is currently stored under controlled and secure conditions at nuclear power plants sites. The controversy has been primarily around a permanent storage solution, and the dialogue has suffered from poor political strategy and community engagement, rather than from a lack of technological solutions. As the JRC concluded, there is “broad scientific and technical consensus” that spent fuel disposal in deep geologic formations is “an appropriate and safe means of isolating it from the biosphere for very long timescales.” Finland and Sweden have successfully communicated the safety case and in doing so have obtained consensus from local communities to host permanent disposal sites and they are on their way to reaching that long-term solution. Finland’s geologic repository is under construction and should start disposal activities in 2025. In Sweden, the two municipalities which will host its repository approved the disposal site last year, allowing the government to now make the final decision.
But why not just invest in wind and solar instead of nuclear? While the use of wind and solar will undoubtedly continue to grow, 100% reliance on renewables as a decarbonisation solution is unworkable for three very good reasons: intermittency, geographical footprint, and limitations on the use of electricity to replace carbon-based fuels in many applications.
Intermittency is currently the Achilles Heel of wind and solar. For a power grid to be stable at any given point in time, the amount of power being generated must equal the amount of power being consumed. That means that as the sun goes behind the clouds or the wind stops blowing, another flexible generation source needs to instantaneously make up the deficit, which typically means gas or coal. Large-scale battery storage is a potential solution, but it is expensive and cannot store enough energy to get us through those cloudy or windless days. In contrast, modern nuclear plants run 24/7 and typically have capacity factors of over 90%.
Geography is a major issue as well. Wind and solar take up a lot of real estate and are not evenly distributed around the world. Solar is a good choice in climates where there is a high level of insolation and vast areas of land to dedicate to solar panels, neither of which applies to most of Europe. In the UK, the problem of relying on solar power will be obvious to anyone who has lived through a long and dark British winter on a steady diet of vitamin D tablets. Offshore wind makes sense for some locations in the UK, but often the best sites for wind farms are not close to the areas with demand for the electricity produced. Nuclear power, with its high energy density, requires a very small fraction of the space.
The third problem is that electricity cannot replace combustion, heat or certain industrial processes in major economic sectors that are big contributors to carbon emissions, such as transportation, industry and district heating. For example, electric heavy duty long-haul trucks and electric ships are not an option because a battery sized to last the long haul distances required would not only be extremely expensive but would take up a lot valuable cargo space. However, hydrogen and ammonia fuels can be used in both. Likewise, iron and steel production (responsible for 7-9% of global carbon emissions) can be decarbonised by using hydrogen in the production process. Hydrogen and ammonia are energy carriers and produce no carbon themselves, but for these elements to be decarbonisation agents, they have to be produced using a carbon-free energy source (most hydrogen and ammonia today are produced using fossil fuels). Renewables can produce hydrogen via a process called low temperature electrolysis, which uses electricity to split water into its constituent elements of hydrogen and oxygen, but the process is costly due to the low efficiency of low temperature electrolysis. Since nuclear reactors produce not only electricity but also heat, they can be paired with a more efficient high temperature electrolysis process, resulting in cheaper and more reliable hydrogen production. Further, its far smaller geographic footprint allows nuclear to produce the immense amounts of hydrogen that will be needed to reach net-zero goals.
One thing everyone seems to agree on is that Europe needs to decarbonise now. Nuclear is a safe and a practical solution to climate change that complements renewables and which can be deployed immediately.
Will we make this decision using our hearts, or our heads?
This article first appeared in ‘The European’ on June 1, 2021.