Nuclear’s Winter: Atomic Energy and Our Zero-Carbon Future
In the early days of the COVID-19 pandemic, billionaire co-founder of Netscape and prominent investor Marc Andreessen penned a viral letter titled “It’s Time To Build”. In the piece, Andreessen pins America’s failure to adequately respond to the virus on the country’s inability to build infrastructure in the real world, including hospitals, housing, manufacturing, transportation, and energy. To address climate change, he proposes the construction of a few thousand nuclear power plants around the world. He’s not alone in his ambition. Nuclear energy has a lot of fans in Silicon Valley, drawn to its promises of harnessing the ingenuity of science to produce almost unlimited energy. But is a vast build-out of nuclear energy really the solution to the climate crisis?
There is perhaps no topic more controversial among clean energy advocates than nuclear power. To some, it’s a critical piece of the low carbon puzzle. To others, it’s a dinosaur best relegated to the 20th century, where it emerged from the grim shadows of Hiroshima and Nagasaki.
With Dwight Eisenhower’s famous “Atoms for Peace” speech in 1953 inaugurating the civilian atomic age, nuclear power experienced rapid growth in the United States and around the world. At its peak, in the late 1980s, nuclear energy provided 17% of the world’s electricity needs. However, in the wake of Chernobyl and rising construction costs, new plant builds slowed to a trickle, and nuclear’s share of global electricity has since fallen to a little over 10% as of 2017. Meanwhile, non-hydro renewables (wind, solar, geothermal) have climbed from a non-factor at the time of nuclear’s peak to capturing 6.5% of electricity generation in 2017.
Solar, in particular, has been growing at a blistering pace, averaging double digit growth in each of the years from 2018–2020. With this rapid growth has come drastically lower prices, such that renewable energy is now often the cheapest form of energy available in the grid.
The rise of cheap, scalable renewable energy has cast a long shadow over nuclear’s future. Its advocates and detractors both have arguments worth considering when thinking about the future of our energy system.
The case for nuclear power
James Hansen, the former director of NASA’s Goddard Institute for Space Studies made famous for his research in climatology and 1988 Congressional testimony that seeded climate change in the public consciousness, has, in recent years, become a strong advocate for nuclear power. In a 2015 piece for the Guardian, he and other prominent scientists called for a vast expansion in nuclear power, to the tune of 115 new reactors every year through 2050.
Nuclear power has several advantages. Most notably: (1) it does not emit greenhouse gases while operating (unlike coal, oil, and gas); (2) it does not consume potentially arable land (like solar farms) or blight the landscape (like wind turbines); and (3) it can provide power 24 hours a day, irrespective of cloudy or still conditions. These advantages are explored in greater detail below.
1. Emissions-free
Unlike fossil fuels, nuclear power does not emit greenhouse gases whilst generating electricity. Critics argue that nuclear power nevertheless has a significant carbon footprint due to the volume of concrete required to build a plant and long term storage vessels, as well as emissions generated during the mining and transport of uranium.
While the exact figures vary depending on the source, a meta-analysis of studies trying to quantify the lifecycle emissions of nuclear energy found its emissions much closer to solar, wind, and hydro than to coal and gas. However, this assumes a ready supply of high-grade uranium ore. If we exhaust the supply, as some have predicted could happen within 20–30 years, nuclear’s lifecycle emissions could double to 131gCO2/kWh.
2. Light on the land
According to NEI (a nuclear industry association), a typical nuclear facility needs around 1 square mile to operate, while solar requires 75 times more land to produce an equivalent amount of energy, and wind requires 360 times the land of nuclear. For context, a more holistic, and independent, analysis (figure 3, below) that included mining and other activities estimated less extreme differences between nuclear, solar, and wind.
Regardless, there is no amount of mathematical dexterity that can elide the basic truth that nuclear plants can produce far more energy in a given space than other low emissions technologies. In fact, nuclear is on par with coal and natural gas in terms of land required per megawatt of output. An ironic consequence of society becoming more conscious of the biosphere is that biosphere-sustaining energy sources like wind, solar and especially hydropower may fall under greater scrutiny for their land use impacts.
3. Always-on, scalable power
Unlike other “clean” sources of energy, nuclear is not dependent on local weather conditions to generate energy, and can therefore provide power 24 hours a day. Additionally, as it relies on fuel instead of the elements as its energy source, nuclear can be sited in communities that don’t have enough sunshine, wind, or space to meet local energy demands.
Nuclear actually has the highest uptime of any energy source, owing to its relatively minimal maintenance needs and the multi-year life of its fuel stock. Hansen and his co-writers argue that scenarios where energy is provided by 100% renewables downplay the impacts of intermittency or rely on large amounts of biomass and hydropower to match nuclear’s uptime and continuous output, with deleterious environmental consequences. However, collapsing prices of lithium ion batteries (a fall of 80% in the last five years) and the deployment of high voltage direct current (HVDC) transmission lines may enable renewable energy to approximate nuclear’s 24 hour uptime.
The case against nuclear power
Critics of plans like those proposed by Hansen argue that their ambitions do not align with reality. Most of these critics contend nuclear’s waning popularity has to do with three key factors: (1) it’s expensive both to build and operate; (2) its plants take too long to build given our race against the climate clock and (3) it’s dangerous, bringing the possibility of (a) meltdowns, (b) weapons proliferation, and (c) long-lived radioactive waste.
1. Cost
Nuclear power is already expensive, and its costs are only increasing. Despite promises over the years of imminent technological breakthroughs, nuclear exhibits the rare “un-learning” curve, becoming more expensive to build over time. Whereas in 2002 a plant could be built for $2 billion USD, by 2008 the price tag had jumped to $9 billion USD. Cost increases are due to ever-escalating safety standards (due to new human and technical failure-points discovered while operating existing plants) and enhanced technological capabilities essentially wiping out traditional cost improvement opportunities. This makes the cost per kWh of energy uncompetitive not only with fossil fuels, but with renewables, which have experienced dramatic price drops in the last decade.
Nuclear now lags all major energy sources in levelized cost of energy (LCOE), an industry standard for illustrating the lifetime cost of an energy source, inclusive of capital costs and operations.
In addition to build costs being high, they’re also unpredictable. Modern nuclear plants routinely deliver over-budget, with one example being Westinghouse’s plant in Georgia, originally costed at $14B, eventually delivering for well over $20B.
New builds aside, it is often cheaper to add new wind and solar capacity than to keep existing nuclear plants running. Other analyses have found that if operating costs saved from closing aging nuclear power plants were reinvested in energy efficiency, 2–3kWh would be saved for every kWh not generated by the plant.
2. Time
As noted in a previous article, humanity is racing against the clock to stem the worst impacts of climate change. In this context, nuclear’s notoriously drawn-out planning to operation (PTO) time is a serious concern. It’s common for the PTO time for new nuclear plants to range between 10–19 years. Even in China, famous for the speed at which it built out its high speed rail network, and, more recently, an entire hospital in Wuhan in the span of a week, nuclear plants generally take around seven years to build. Nuclear plants regularly come in over-budget and behind schedule, like in France, where an attempt to build a next generation plant delivered six years late.
France is often hailed by nuclear advocates as a success story, having switched a majority of its energy generation to nuclear within 20 years. Within that success story, however, is a warning. France built 58 reactors over that period, a rate of 3 reactors per year. James Hansen’s nuclear ambitions call for the construction of 115 new reactors, every year, for 35 years. Current plans see 48 reactors being built, worldwide, over the next seven years. That is under seven reactors per year.
With such a long lead time, investing in nuclear carries an opportunity cost, tying up billions of dollars over 10–20 years that could have been invested in renewable projects that tend to deliver within 2–5 years. It adds up to an irreversible strain on the global carbon budget.
3. Danger
Nuclear energy carries three distinct risks: (a) meltdowns, (b) proliferation, and (c) long term storage of waste.
(a) Meltdowns: There have been three major nuclear accidents since the introduction of the technology: Three Mile Island (1979), Chernobyl (1986), and Fukushima (2011). Each accident started with a loss of coolant. In Fukushima, the reactors automatically shutdown during an earthquake, but a subsequent tsunami knocked out the diesel cooling systems, leading to unmanaged decay heat in the reactor core and meltdowns. An accident like Chernobyl is unlikely with modern plants as most use water as both the coolant and moderator (the element which enables the energy-producing fission reaction), meaning when there is a loss of coolant, the resulting high temperatures boil off the water, stopping the fission reaction. The plant in Chernobyl used graphite as its moderator, therefore when there was a loss of coolant, the fission reaction continued unabated, leading to uncontrollable high temperatures and the reactor melting through its containment structure.
The health impacts of these accidents is highly contentious due to, among other things, difficulties assigning causality between radiation and cancer deaths years later. Officially, only 31 people died from injuries sustained during the Chernobyl meltdown. Similarly, there were no immediate deaths reported from the Fukushima meltdowns. Estimates of total deaths linked to these two events range from the low thousands to the high tens of thousands.
Deaths are also an imperfect measure of the harm caused by a nuclear reactor meltdown. Studies have shown an uptick in mental health issues including suicide and anxiety, learning disabilities, and non-fatal health issues stemming from these events.
Still, it is fair to argue that the relative lethality of nuclear energy is vastly overstated in the public imagination, given the 5 million deaths per year attributable to air pollution caused in part by fossil fuels and biomass, not to mention any future harm caused by climate change, which nuclear energy can help abate.
The economic damage, conversely, is probably under-appreciated by the general public. The earthquake and tsunami that led to the Fukushima meltdowns is estimated to have caused $500B in damages. The dislocation, contamination, and output loss caused by the meltdowns is thought to have added an additional $460B to $640B in damages.
(b) Nuclear proliferation: Given how close the world has come to nuclear war in the past, the risk of nuclear weapons proliferation should be taken seriously.
The vulnerability of traditional nuclear plants to theft of nuclear material by non-state actors is low. In the standard once through fuel cycle, there’s no step where fuel could be stolen or diverted, because there is no way to separate the plutonium from the highly radioactive fission products. However, countries such as France reuse their spent fuel, a process which carries a risk of plutonium theft.
The real proliferation risk lies in states continuing to enrich uranium from the 2–3% required for energy to the 80–90% that could be used to make a bomb. India, Pakistan, North Korea, and South Africa have all developed nuclear weapons by secretly enriching fuel at their civilian power plants. A broad expansion in states with nuclear reactors could drastically increase the number of nuclear-armed countries, many with less stable governments than today’s nuclear powers.
(c) Nuclear waste: Spent fuel rods remain deadly to humans for tens of thousands of years. Given nuclear energy has been around for over 70 years, one would be forgiven for thinking we had devised a permanent, safe method for storing radioactive waste without risks of it seeping into the ground water, or being stolen by radicals. In fact, nearly all radioactive waste is stored on-site at nuclear power plants, either in pools or “dry cask” storage, where the spent fuel is immersed in an inert gas inside a steel cylinder, that itself is encased in 100 tons of concrete. These fuel rods are still so potent that they manage to heat the outside of the concrete casing to 30 degrees celsius.
Centralized storage would bring benefits, including drastically reducing the number of sites that need to be protected from potential attacks and natural disasters, as well as making it easier to retrieve spent fuel for use in reprocessing fuel cycles. However, only one country, Finland, is close to implementing permanent underground storage.
A number of startups are piloting deep horizontal storage wells, using techniques pioneered in the fracking industry. These trials have shown promise, but, as with other aspects of next generation nuclear, have yet to bear fruit.
The great unresolved question at the heart of the storage debate is simple: as Allison Macfarlane, President Obama’s head of the Nuclear Regulatory Commission noted, no one can guarantee that any solution will stand the test of geologic time, over which spent fuel rods will remain dangerous to humans and all other life on earth.
Nuclear’s uncertain future
The (long awaited) next generation
For as long as nuclear power has existed there have been promises of technological breakthroughs right around the corner that would render the above criticisms moot. Chief among these promised innovations are advancements like nuclear fusion, fast breeder reactors, and small modular reactors.
Nuclear fusion promises to harness the same process used by the sun to generate heat to produce three to four times the energy density of the traditional fission process. The process does not create long-lived radioactive waste, does not utilize materials that could be fashioned into a bomb, and does not pose a meltdown risk. Alas, investment into research and development has stalled, with significant technological and financial hurdles yet to clear. Even the most optimistic projections don’t see fusion becoming a commercial player until well into the second half of the century.
The conventional once through fuel cycle leaves spent fuel rods with 96% of their energy potential still untapped. Fast breeder reactors (FBRs) aim to reuse the spent fuel until it is consumed, thereby resolving the issue of radioactive waste and proliferation. However, doubts remain about the viability of the technology, with $100B invested over 60 years into fast breeder R&D and no operating plants to show for it. Additionally, while FBRs can help eliminate waste stockpiles which pose environmental and proliferation risks, the process itself, in which plutonium is extracted from spent fuel for reprocessing, creates an opportunity for theft and proliferation risks of its own.
Small modular reactors (SMRs) are exactly what they sound like — miniaturized reactors, generally with a maximum capacity of 300MW, compared to the 1000MW+ behemoths currently in operation. Their size lends them a number of benefits, namely: they can be passively safe, meaning they don’t have enough fuel to melt their containment chambers in the event of an accident, and they have fewer pumps and pipes that could fail. Their prefabrication according to a standard design means that SMRs can be deployed to remote locations, and cost less to build, train people on, and secure. However, they still have many of the same issues as traditional nuclear: radioactive waste products, safety concerns, and lack of cost competitiveness with renewables. A number of firms have tried and failed to develop and deploy SMRs in the recent past, so there is cause to greet new projects with skepticism.
Moving on too soon in Germany and America
In recent years Germany and the United States have embarked on a nuclear decommissioning spree. In Germany, a popular anti-nuclear movement spurred by the Chernobyl disaster was reanimated by the Fukushima meltdowns, leading to a commitment to end the country’s reliance on nuclear power. 11 plants have been closed over the last decade, with the remaining six slated to shutter by 2022.
In the United States, where the abundance of cheap natural gas has decimated nuclear’s already shaky profitability, a number of plants have closed in recent years, eliminating 40 terawatts of emissions-free energy. All told, 15 to 20 US nuclear plants are at risk of closure over the next 10 years.
While public opposition and profitability are both valid reasons for moving on from nuclear energy, from a climate change perspective, the moves have been disastrous. Clean nuclear capacity has been replaced by the incumbent fossil fuels — coal and natural gas. At a time when countries have committed to drastically cutting emissions, Germany’s plant closures are estimated to have increased its annual emissions by 5%. Given we need to stay within a 570 gigaton CO2 budget over the next 30 years if we are to have a chance of averting climate change’s worst impacts, these losses of emissions-free energy, regardless of the valid reasons behind them, make the climate challenge that much harder.
Cautious optimism in Canada
There has not been the same public opposition to nuclear energy in Canada. 15% of the country’s energy comes from nuclear power. The majority of the country’s nuclear reactors are located in Ontario, my home province, where they supply 53% of the jurisdiction’s electricity. While new plant builds are highly unlikely, Ontario has committed to a multi-billion dollar refurbishment plan for the province’s reactors, extending their life well into the 2060s.
A number of Canada’s provinces recently came together to pen a small modular reactor roadmap, which calls for the commercialization of SMRs to meet energy needs in mines and rural communities, where they can replace diesel-powered generators. Seattle-based Ultra Safe Nuclear Corp has put forward a plan to have a SMR operational northwest of Ottawa by 2023. It is an ambitious timeline given the nuclear industry’s spotty track record of timely delivery, but would mark an important milestone worldwide for the next generation technology.
Nuclear energy is the ultimate science project, harnessing the fundamentals of physics to create nearly unlimited energy from the collision of single atoms. It’s an incredible achievement, and yet its future is cloudy. As discussed above, nuclear power has its benefits: it is emissions-free while operating; it does not take up valuable land where animals or humans can live or plants can grow; and it produces energy round the clock. And yet, the downsides prompt serious consideration: expensive and lengthy builds at a time when we need clean energy delivered cheaply and quickly; and the triple threat of meltdowns, weapons proliferation, and harmful long-lasting waste products.
So what’s the prescription for nuclear power? Do we move on, or do we do as scientists like James Hansen, and more recently, prominent venture capitalists like Marc Andreessen, have proposed, and begin a massive scale up of nuclear energy?
Based on my review of the arguments on both sides of the question, I’d advocate a middle path. Where it is practical and safe, we should keep existing nuclear power plants running, until their production can be backfilled by renewables rather than coal or gas. We should continue to invest in the research and development of new technologies like fusion and small modular reactors. Could the money be wasted? Sure. But it’s better to prepare for contingencies for our clean energy future, if solar, wind, and storage hit unforeseen roadblocks on their current trajectory of grid dominance. Where possible, though, investment in new energy generation should be allocated to rapid deployment of solar, wind, and storage. The climate math is daunting, and the time we have to avert catastrophic impacts grows shorter by the day. Committing to further build outs of traditional nuclear power plants will mean at minimum 10–20 additional years of coal-fired power. New technologies show promise, but it will also be decades before they bear fruit. Time, unfortunately, is not on our side.
