Tripling nuclear energy by 2050 will take a miracle, and miracles don’t happen

The recent COP28 climate conference held in Dubai saw a concerted effort by a few governments to promote expanding nuclear energy as a solution to the climate crisis. Led by the US Department of Energy, a pledge to triple nuclear energy capacity by 2050 attracted a mere 22 countries. The contrast in ambition and global support with an agreement on tripling renewable energy and doubling energy efficiency by 2030—signed by 123 countries, and enshrined in the final outcome document—couldn’t be greater. But even this level of ambition, i.e., tripling capacity by 2050, is inappropriate when it comes to nuclear energy.

Between 1996 and 2022, the proportion of global electricity generated by nuclear reactors has dropped . This decline stands in sharp contrast to the remarkable upward trajectory observed in renewable energy sources, particularly solar and wind power. Over the same period, the share of global electricity produced by modern forms of renewable energy has gone from a mere 1.2 per cent to 14.4 per cent.

The difference is only set to grow. Investment in renewable energy sources is growing rapidly, reaching a record of , constituting 74 per cent of all power generation investments in 2022, while nuclear and coal accounted for only 8 per cent each. Solar photovoltaics, especially when built at large (utility) scale, has become the least costly option for new electricity capacity in recent years; in 2020, the International Energy Agency pronounced that solar is “the new king of the world’s electricity markets”.

As of mid-2023, there were just 407 operable nuclear reactors worldwide, which is 31 below the peak of 438 reactors in 2002, with a combined capacity of 365 gigawatts. These reactors are mostly old ones, built decades ago; the average age of the fleet has grown from 11.3 years in 1990 to 31.4 years in 2023. For nuclear energy to even maintain its current level of electricity production, most of these reactors will have to replaced. As detailed below, any attempt to replace nuclear capacity will be exorbitant. Because of these high costs, and rapid pace of building renewables, nuclear energy can simply not maintain its share of electricity production.

The decline in nuclear capacity is not due to lack of interest from governments. Between 2002 and 2023, there was a so-called nuclear renaissance. In the United States, the Bush administration’s 2005 Energy Policy Act offered numerous incentives, such as loan guarantees, to promote nuclear power. Spurred by these incentives, US electricity companies proposed building more than 30 reactors, many of them expected to start operating by 2021. 

Only four of these reactors proceeded to actual construction but two of these reactors in the state of South Carolina were abandoned after $9 billion was spent because of massive cost increases and time delays. That led the Westinghouse Electric Company, a subsidiary of Japanese company Toshiba and the largest historic builder of nuclear power plants in the world, to file for Chapter 11 bankruptcy protection.

The remaining two reactors were built at the Vogtle site in Georgia. The first of these units began operating in 2023, taking over 10 years from when construction started—well above the “36 months” that the reactor’s designer, the Westinghouse company, had promised. Costs rose from an estimate of $14 billion when construction started to over $35 billion. This is in the United States, the country with historically the largest nuclear fleet.

In France, the country with the most reliance on nuclear energy, the Flamanville-3 nuclear reactor is now estimated to cost around $15 billion—four times what was forecasted when Électricité de France began building it. Historically, both in the United States and France, costs have risen as more reactors were built, and so we might expect future nuclear plants to be more expensive.

The other reason to expect future costs to go up is because of the push for small modular reactors (SMRs) to revive the nuclear industry. Small reactors lose out on economies of scale, and therefore start off with an economic disadvantage. Even if their absolute cost is lower than that of a large nuclear reactor, they are more expensive when compared on the basis of how much electricity they can provide (i.e., on a per megawatt basis).

A project involving six NuScale small modular reactors that was proposed to be built in Idaho was estimated to cost $9.3 billion for just 462 megawatts of power capacity. In comparison to the Vogtle project in Georgia, when that project was at a comparable stage—that is, when it was still on paper—the estimate for the UAMPS project is around 250 per cent more than the initial per megawatt cost of the Vogtle project.

SMRs have also suffered construction delays. In Russia, the first SMR that has been deployed is the KLT-40S, based on the design of reactors used in the small fleet of nuclear-powered icebreakers that Russia has operated for decades. Yet, the KLT-40S, which was expected to take three years to build actually took 13 years. That is even more than the large reactors mentioned above.

These delays also underscore what energy analyst Amory Lovins pointed out: “To protect the climate, we must abate the most carbon at the least cost—and in the least time—so we must pay attention to carbon, cost, and time, not to carbon alone.” Nuclear power fails both the tests of cost and time. Investing further into nuclear technology with its concomitant loss of time will accentuate the unjust and unequal impacts on countries in the Global South, who are already dealing with severe climate impacts because developed countries like the United States have not reduced their carbon emissions in accord with their financial capacities. 

Given these hard economic realities, what explains the pledge put out by the US government? Looking at who signed it and who didn’t suggests that the pledge is out there for geopolitical reasons. Note, for example, that Russia and China are missing from the list of signatories to the declaration: China is the country building the most nuclear reactors domestically and Russia is the country exporting the most reactors. No country from South Asia joined this pledge either.

In his essay about miracles, the 18th century British philosopher David Hume wrote “A wise man…proportions his belief to the evidence”. (Today, we might say, a wise person proportions their belief to the evidence.) The evidence that nuclear energy cannot be scaled up quickly is overwhelming. It is time to abandon the idea that further expanding nuclear technology can help with mitigating climate change. Rather, we need to focus on expanding renewables and associated technologies while implementing stringent efficiency measures to rapidly effect an energy transition.

Farrukh A Chishtie is an atmospheric and earth observation scientist with extensive experience in various experimental and modelling disciplines. He has more than 18 years of research experience, and is presently leading the Peaceful Society, Science and Innovation Foundation, a non-profit organisation dedicated to serving communities afflicted by climate change, wars and pandemics. 

MV Ramana is the Simons Chair in Disarmament, Global and Human Security and Professor at the School of Public Policy and Global Affairs, at the University of British Columbia in Vancouver, Canada. He is the author of The Power of Promise: Examining Nuclear Energy in India (Penguin Books, 2012) and Nuclear is not the Solution: The Folly of Atomic Power in the Age of Climate Change (forthcoming from Verso books) 

Views expressed are the authors’ own and don’t necessarily reflect those of Down To Earth