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Nuclear Power

Can nuclear power help save us from climate change?

The technology’s slide must be reversed, the International Energy Agency says, but significant barriers exist

by Jeff Johnson, special to C&EN
September 23, 2019 | A version of this story appeared in Volume 97, Issue 37


Globally, nuclear power is on the skids. Its contribution to electricity generation is in a free fall, dropping from a mid-1990s peak of about 18% of worldwide electricity capacity to 10% today, according to the International Energy Agency (IEA). The agency expects the downward spiral to continue, hitting 5% by 2040 unless governments around the world intervene.

The driver for that intervention would be nuclear reactors’ ability to generate energy with low greenhouse gas emission. To meet the world’s energy needs and avoid the worst effects of climate change, low-carbon electricity generation must increase from providing 36% of the world’s energy today to 85% by 2040, the IEA says.

Electricity sources

The share of electricity generated globally from low-carbon sources has been relatively flat since it peaked in the mid-1990s.
Source: International Energy Agency, “Nuclear Power in a Clean Energy System.”

“Without an important contribution from nuclear power, the global energy transition will be that much harder,” IEA executive director Fatih Birol says in a statement accompanying an IEA nuclear power report. “Alongside renewables, energy efficiency and other innovative technologies, nuclear can make a significant contribution to achieving sustainable energy goals and enhancing energy security.”

But steep barriers to a nuclear energy renaissance exist, among them aging reactors, high costs to build new ones, safety concerns, and questions about how much nuclear is needed in the world’s energy mix.

Historically, nuclear power has played its biggest role in advanced economies, where it makes up 18% of total electricity generation today. France is the most dependent on nuclear energy, with 70% of its electricity generated from nuclear reactors. By number of operating reactors, the US leads with 98 power plants capable of generating 105 GW; France is second with 58 reactors generating 66 GW of electricity.

However, many of those reactors are old. In the US, the European Union, and Russia, plants average 35 years or more in age, nearing their designed lifetimes of 40 years.

Building new nuclear power plants based on traditional designs will be nearly impossible in developed economies, IEA analysts say. The challenges include high costs and long construction times, as well as time needed to recoup costs once plants start running, plus ongoing issues with radioactive waste disposal. In addition, the competitive electricity marketplace in the US makes it hard to sell nuclear energy against that generated more cheaply through natural gas, wind, or solar. Right now, only 11 nuclear plants are under construction in developed economies—4 in South Korea and 1 each in seven other countries.

There is more potential for nuclear energy expansion in developing nations with state-controlled, centralized economies. China is the world’s third-largest nuclear generator, with 45 reactors capable of producing 46 GW of electricity. China also has the biggest plans for new power plants, with 11 at various stages of construction, the IEA says. India is building 7; Russia, 6; and the United Arab Emirates, 4, with a sprinkling of other new plants coming throughout the rest of the world. All will be state owned, the IEA says.

The nuclear industry’s main hope for future expansion lies in a new generation of small, modular reactors that generate less than 300 MW each and are amenable to assembly-line construction. These are still under development, however, with none licensed or under construction.

A middle path between new plants and no plants is lifetime extensions for existing reactors. The IEA estimates the costs for maintenance and improvements needed to continue operating an existing nuclear reactor for an additional 10–20 years would be $500 million–$1.1 billion per gigawatt, an amount the IEA says is comparable to constructing a renewable—solar or wind—system of the same size. The result would be effectively 1 GW of new, low-carbon electricity without the delays involved in siting and building a new solar field or wind farm.

In the US, the Nuclear Regulatory Commission (NRC) has already renewed and extended the operating licenses from 40 to 60 years for 90 of the 98 operating reactors. The industry is now focusing on renewals to operate for up to 80 years. Similarly, other countries are considering extending existing reactor operations but for shorter periods, the IEA reports.

These extensions present what the Union of Concerned Scientists (UCS) terms a “nuclear power dilemma.” The nonprofit organization, which advocates scientific solutions to global problems, has been a frequent nuclear industry critic.

Aging nuclear plants

Many nuclear power plants in the US, the European Union, and Russia are reaching the end of their design lifetime, while those elsewhere in Asia are much younger.
Source: International Energy Agency, “Nuclear Power in a Clean Energy System.”

“We are very cognizant of this climate challenge and the need to act quickly to cut greenhouse gas emissions,” says Rachel Cleetus, the UCS’s climate and energy policy director. The UCS’s solution for providing energy in a warming world is to tax and cap carbon dioxide emissions and introduce a low-carbon electricity standard for all energy sources. Such measures would drive the construction and development of low-carbon energy facilities and technologies, the UCS says.

For nuclear energy in particular, the organization endorses temporary financial support for the extension of some plants, conditioned on rate protection for consumers, safety requirements, and greater investments in renewables and energy efficiency. “We can’t just give them lots of money and blanket life extensions,” Cleetus says. Scenarios and mathematical models run by the UCS show nuclear is very unlikely to grow beyond providing at most 16% of the world’s electricity generation capacity by 2050 even with aid, far short of the 85% or more of the low- or noncarbon generation needed to address global warming.

Underlying the debates about power plant costs and operating lifetimes are questions of safety and risks—real and perceived—of nuclear reactors and radioactivity. These concerns have made nuclear power unpopular in the US, Germany, Japan, and elsewhere.

The San Onofre Nuclear Generating Station (SONGS), resting on the US West Coast north of San Diego, provides an example of why. Seven million people live within 80 km of the plant.

A stormy relationship between SONGS and its surrounding community goes back decades. Most recently, the facility was completely shut down in 2013 after two nearly new steam generators failed. The replacements were part of a $670 million overhaul that was supposed to provide 20 more years of life for the plant.

Then, while transferring used fuel into a storage vault last year, contractor Holtec International mishandled and nearly dropped a 50-metric-ton spent fuel canister. The NRC subsequently cited plant owner Southern California Edison for failing to properly report the incident, as well as conditions that led to it. The public learned about the slipup from a whistle-blower speaking at a community meeting. The event halted fuel transfer operations, which are just now restarting.

“Repairs and replacements could be done properly at nuclear plants,” says L. R. “Len” Hering Sr., a retired rear admiral of the US Navy who lives near SONGS and is cochair of a task force established by Rep. Mike Levin (D-CA) to address community safety concerns at the facility.

Hering bases that assessment on his navy experience. “Ships are designed to last roughly 30 years, and when the navy goes through a process of life extension, we do extensive testing and evaluation,” he says. “We make certain all components are up to snuff. In the navy, repairs are made by a focused group of individuals separate from the ship’s operators, and it is not about cost.”

He has not seen a similar level of attention and rigor at SONGS. Once a nuclear advocate, he has cooled on nuclear power because of concerns over management and regulation. “I don’t believe the NRC has the capacity to properly inspect and oversee operations or maintenance,” he says.

Meanwhile, some of the groups advocating for strong action to address climate change question whether more nuclear energy is necessary. Over the past 20 years, as nuclear power generation has declined, renewable sources have expanded by some 580 GW—more than the output of all the world’s nuclear power plants—to make up the difference. Consequently, the overall share of low-carbon electricity sources—hydropower, nuclear, solar, and wind—has stayed even at about 36%.

The IEA applauds the growth of renewables but says that it is unprecedented and not sustainable. Hence the agency’s support for nuclear power.

However, energy researchers at the World Resources Institute and the UCS, speaking at a recent US congressional hearing, say renewable sources will continue to expand, and major increases in energy efficiency are on the horizon. In addition, the researchers expect that as more renewable energy facilities come on line, new technologies will be developed to address the challenge of variable output from renewable energy sources, such as with solar on an overcast day.

Overreliance on nuclear might in fact stall development and installation of technologies needed for a transition to a low-carbon future, Cleetus argues. Her modeling shows that capital investment needed for renewable energy development—building high-voltage power lines, advanced batteries and other storage systems, and of course, renewable resources themselves—could be funneled off to build and retrofit more nuclear power plants. And then there are those who question whether nuclear energy can even be called low carbon if greenhouse gas emissions are considered for the full energy cycle, including plant construction, uranium mining and enrichment, fuel processing, plant decommissioning, and radioactive waste deposition.

Ultimately, the future of nuclear power will turn on the world’s need for energy security and how it weighs the costs of action and inaction in the face of growing impacts of climate change.

Jeff Johnson is a freelance writer based in Washington, DC.


This story was revised on Sept. 26, 2019, to correct and clarify what happened after a spent fuel canister was nearly dropped at the San Onofre Nuclear Generating Station in 2018. The plant did not yet have a permit to be decommissioned, but spent fuel was being moved into storage. Also, the Nuclear Regulatory Commission was notified of the incident, but neither formally nor within the required time window for such reports.


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