The controversial future of nuclear energy – a crash course
It’s the answer to the energy crisis to some, or just as bad if not worse than fossil fuels to others. Certainly, nuclear meltdowns like Chernobyl and Fukushima aren’t anything to cheer for, so why are opinions on this matter so divided? Is it really the best option we’ve got for CO2-free energy production? At what costs does it come?
In preparation for our upcoming GreenDocs event on the 28th of February, this blogpost will give you some basic knowledge on the topic to make parttaking in the discussion easier.
You can sign up for the event by clicking here!
What is nuclear power?
Nuclear power is generated by splitting atoms to release the energy held at the core, or nucleus, of those atoms. This process, nuclear fission, generates heat that is directed to a cooling agent – usually water, but liquid metal or molten salt can also be used. The resulting steam spins a turbine connected to a generator, producing electricity. During this process, more neutrons are released colliding with more atoms, creating a chain reaction of nuclear fission.
Currently, about 450 nuclear reactors provide about 11% of the world’s electricity.
Types of nuclear reactors
Most of the reactors in the U.S. are either boiling water reactors, in which the water is heated to the boiling point to release steam, or pressurized water reactors, in which the pressurized water does not boil but funnels heat to a secondary water supply for steam generation. Other types of nuclear power reactors in use include gas-cooled reactors, which use carbon dioxide as the cooling agent and are used in the U.K., and fast neutron reactors, which are cooled by liquid sodium.
But that is not all. National Geographic explorer Leslie Dewan, for example, wants to resurrect the molten salt reactor, which uses liquid uranium dissolved in molten salt as fuel, arguing it to be safer and less costly than reactors in use today.
While current nuclear plants continue to age, and newer ones fail to compete on price with natural gas and renewable sources such as wind and solar, scholars are researching and developing innovations such as smaller, modular reactors which could be portable and easier to build – aimed at saving this industry in crisis.
The holy grail for the future of nuclear power however, involves nuclear fusion, which generates energy when two nuclei smash together to form a single, heavier nucleus. Fusion could deliver more energy more safely and with far less harmful radioactive waste than fission, but just a small amount of people have manager to build working nuclear fusion reactors – under which a 14-year-old from Arkansas. Organizations such as the French ITER and German Max Planck Institute are working on commercially viable versions, which so far remain elusive.
The process of nuclear fission of course has to be fueled. The most common fuel is uranium, an abundant metal found throughout the world. To be used by a nuclear reactor however, it must be processed into an enriched version called U-235, which splits apart more easily. Although uranium is about 100 times more common than silver, U-235 is relatively rare at just over 0.7% of natural uranium. A byproduct of nuclear fission, plutonium, can also be used as nuclear fuel.
Since nuclear fuel can also be used to create nuclear weapons, only nations that are part of the ‘Nuclear Non-Proliferation Treaty (NPT)’ are allowed to import uranium or plutonium. The treaty promotes the peaceful use of nuclear fuel, as well as limiting the spread of nuclear weapons.
Typically, a nuclear reactor uses about up to 30 tons of uranium every year. In comparison, a coal power station of equivalent size requires more than 2,5 million tons of coal to produce as much electricity. Source.
There are two ways to mine uranium, by in-situ leaching (57% of world production) or by conventional underground or open-pit mining of ores (43%). During in-situ mining, a leaching solution is pumped down into uranium ore, where it dissolves the minerals. The uranium-rich fluid is then pumped back to the surface and processed to extract the uranium compounds. In conventional mining, ores are processed by grinding the ore materials and extracting the uranium by chemical leaching. After collecting the uranium, it is processed in conversion and enrichment facilities, increasing the level of U-235 to 3%-5%.
The annual worldwide production of uranium resides around 50,000 tonnes. Kazakhstan, Canada and Australia are, respectively, the top three uranium producers, and account for 68% of world production.
Notable is the fact that uranium production has been limited in recent years, mainly due to a sluggish market according to Vinneth Bajaj, from GlobalData. This was further impacted by the COVID-19 pandemic; production at Canada’s Cameco’s Cigar Lake, which accounts for 12-13 percent of global production, was suspended in March 2020 to contain the coronavirus outbreak, remaining for almost a year with a short hiatus of three months in between. In April 2020, Kazakhstan also reduced activities for nearly four months at all of its uranium mines.
Nonetheless, global uranium production is expected to grow at a compound annual growth rate of 6.2 percent over the period of 2021-2025, reaching 65,2 kt in 2025, Bajaj said.
Since a nuclear reactor typically uses around 30 tonnes of uranium on a year basis, the current annual production rates aren’t really that promising. According to the Nuclear Energy Agency, identified uranium resources total 5,5 million metric tons, and an additional 10,5 million metric tons remain undiscovered. This would be equal to a rough 230-year supply at today’s consumption rate.
Meanwhile, further exploration and improvements in extraction technology are likely to at least double this estimate over time. Taking steps such as using more enrichment work and separating plutonium and uranium from spent ‘low-enriched uranium’ and using them to make fresh fuel could reduce uranium requirements by another 60%.
Nuclear power and climate change
Modern society is becoming more and more dependent on electricity. Whilst electricity is clean at the point of use, its generation currently produces over 40% of all energy-related carbon emissions. Decarbonising the electricity supply, whilst providing affordable and reliable electricity to a growing global population, must be central to any climate change strategy.
Key in this shift towards a sustainable energy industry is of course the use of renewable energy. The problem with this is the fact that they are intermittent or ‘variable’ sources of energy, meaning they are often limited by a lack of fuel (i.e. wind, sun or water). As a result, they need backup power sources such as large-scale storage or nuclear energy.
Considering the dependency on mined, finite resources, nuclear power can’t be seen as renewable energy, but since reactors barely emit any greenhouse gasses, proponents argue it’s a climate change solution, or at the very least, something we could use until we’re able to develop comprehensive alternatives.
Nuclear energy has shown to have the potential to be the catalyst for delivering sustainable energy transitions long before climate change was on the agenda. In France, for example, nuclear played a minor role in the electricity system, until it became an agenda point in the 80s. Since then, even though the total demand for electricity has only been growing, their use of fossil energy has only been decreasing. Nuclear has quickly grown out to be their main source of energy; making up for 70% of France’s electricity.
The risks and downsides
Opponents of nuclear energy often point to the problems of long-lived nuclear waste as well as the rare but devastating nuclear accidents, such as those at Chernobyl and Fukushima. The Chernobyl disaster happened when flawed reactor design and human error caused a power surge and explosion at one of the reactors. In the case of Fukushima Dai-ichi, the aftermath of the Tohoku earthquake and tsunami caused the plant’s catastrophic failures. Another incident happened at the Three Mile Island plant in the U.S., which began with failures in the non-nuclear secondary system leading to a chain reaction of failures, causing a partial meltdown of the power plant. Such incidents are great contributors to the decline of nuclear power and the caused the rise of anti-nuclear safety movements.
We’ve learned that although nuclear power plants and nuclear waste have a fairly low probability of failure, they do have extremely high consequences. It is very hard for even scientifically-trained, rational people to agree on how such situations should be treated. In the U.S. for example, private insurers will not issue insurances for nuclear reactors, despite the low probability. For this reason, all U.S. nuclear plants are insured by the taxpayers; if they have accidents, the American society as a whole pays for them.
Nuclear waste also presents difficult problems, mostly regarding long-term technical storage, even though it is considerably less than many other poisons and toxins that we regularly produce and discharge. The technical difficulties of the storage process itself, combined with the political ones (which make it more or less an impossible problem to solve) make it increasingly unclear that nations will do anything sensible with its waste with regards to the long term. Currently, most nuclear waste is stored on-site at the plants. Improperly or unsafely storing said waste could create many problems, increasing the probability and consequences of failures. The storage problem is an immensely long-term issue, of the sort that human beings are notoriously bad for planning for.
Another reason to oppose nuclear power plants is the fact that they are non-linear systems: the entire system runs in one direction, from ‘A’ to ‘Z’ so to say. Nuclear plants have numerous flows with complicated processes going in them, making both the cause as well as the results of a single failure point hard to predict or trace back. It also means that keeping total knowledge of the system is very difficult. Sociologist Charles Perrow has pointed out that this makes them prone to what he calles ‘normal accidents’, which are theoretically rare failures of multiple parts of the system, in unpredictable ways. This is exactly what happened at Three Mile Island, where a single malfunctioning valve started a chain reaction of technical and human errors, leading to an extremely dangerous situation that fortunately resolved itself safely.
At the same time, the economics for nuclear are not especially good; it’s an expensive power source with very high capital costs. In some economies it can be cheaper than fossil fuels, but in most it is not. This is a reason why nuclear power was foundering in the U.S. well before the Three Mile Island accident, but after the oil crisis ended, it just wasn’t economically competitive. Making the existing plants competitive involved cutting very close efficiency margins and running them for very, very long times. This incentive for cutting corners and smoothing over issues that could lead to plant downtime – expecting them to run for several decades over their original projected lifetime – has led to many people distrusting the nuclear industry, and to certain patterns of cover-ups and shoddy practices in many countries where the free-market economic model on nuclear holds.
Whether nuclear will be more competitive than fossil fuels in the future is an open question given the apparent plentifulness of said fuels. There are, of course, non-free-market mechanisms to make it more competitive (e.g. subsidies or carbon taxes), but it won’t provide us with any economic advantages whatsoever anytime soon.
If we want to realistically reduce our global carbon footprint in the amount of time necessary to avert or mitigate the impending disasters of climate change, nuclear will need to be part of that solution. Considering the nuclear industry as it currently exists and the economic situation of it, prudent operation and regulation, along with subsidization of research and development of nuclear power are essential to fully justify its use.
Looking at the current economic development of nuclear in the U.S. (the leading country regarding nuclear power plants), renewables are on an upward trajectory, while nuclear is the lowest agenda point.