Converting Coal Power Plants to Nuclear Gains Steam

A U.S. Department of Energy report identifies over 300 coal plants that could be swapped over

3 min read
illustration of a building concept

This illustration shows TerraPower’s Wyoming project, which aims to retrofit an existing coal plant with a sodium fast reactor.


On a planet aspiring to become carbon neutral, the once-stalwart coal power plant is an emerging anachronism.

It is true that, in much of the developing world, coal-fired capacity continues to grow. But in every corner of the globe, political and financial pressures are mounting to bury coal in the past. In the United States, coal’s share of electricity generation has plummeted since its early 2000s peak; 28 percent of U.S. coal plants are planned to shutter by 2035.

As coal plants close, they leave behind empty building shells and scores of lost jobs. Some analysts have proposed a solution that, on the surface, seems almost too elegant: turning old coal plants into nuclear power plants.

On 13 September, the U.S. Department of Energy (DOE) released a report suggesting that, in theory, over 300 former and present coal power plants could be converted to nuclear. Such a conversion has never been done, but the report is another sign that the idea is gaining momentum—if with the slow steps of a baby needing decades to learn to walk.

“A lot of communities that may have not traditionally been looking at advanced nuclear, or nuclear energy in general, are now being incentivized to look at it,” says Victor Ibarra Jr., an analyst at the Nuclear Innovation Alliance think tank, who wasn’t involved with the DOE study.

Conversion backers say the process has benefits for everybody involved. Plant operators might save on costs, with transmission lines, cooling towers, office buildings, and roads already in place. Once-coal-dependent communities might gain jobs and far better air quality.

“I think it’s something that people have been talking about for a while,” says Patrick White, project manager at the Nuclear Innovation Alliance.

DOE analysts screened 349 retired and 273 still-operating coal-plant sites across the United States. They filtered out sites that were retired earlier than 2012, sites that weren’t operated by utilities, and sites deemed unsuitable for nuclear reactors (such as plants in disaster-prone or high-population-density areas). That left 157 recently retired and 237 operating sites that could—in theory—house nuclear reactors.

Not all of these remaining coal plants are perfect fits, however. Most nuclear plants around the world today are large light-water reactors, with capacities well over a gigawatt—quite a bit more than typical coal plants. Large reactors need consistent and prolific water sources to cool themselves, something not every old coal plant can provide. DOE analysts flagged only 35 recently retired and 96 operating coal sites that could house a large light-water reactor within half a mile.

But in the future, not all reactors might be so large. Many still-speculative small modular reactor designs might deliver just a few hundred megawatts. (In Hainan, China, Linglong One—the world’s first small modular reactor plant—is now under construction.) Depending on the design, these could be cooled with less water or even air, making them far more feasible fits for coal sites. DOE analysts found 125 recently retired and 190 operating sites that could house such small reactors.

Either option will be an uphill battle. In the United States, any new reactor must gain the blessing of the federal Nuclear Regulatory Commission (NRC), a process that can take up to five years and drive up costs in a sector already facing rising prices. Only one nuclear power plant is currently under construction in the United States, in eastern Georgia.

A specific challenge would-be-conversions must face is that the NRC’s standards—both for atmospheric pollution and for the amount of radiological material a reactor can release—are much tighter than federal standards for coal plants.

On the state level, no fewer than 12—California, Connecticut, Hawaii, Illinois, Maine, Massachusetts, Minnesota, New Jersey, New York, Oregon, Rhode Island, and Vermont—all have their own conditions restricting new nuclear construction.

Even if regulations didn’t stand in the way, coal-to-nuclear conversion has never been done. However, there is one project that has made some headway.

In Kemmerer, Wyo., nestled in the foothills of the Rocky Mountains, the nuclear energy firm TerraPower plans to retrofit an existing coal plant with a sodium fast reactor. The firm is planning to start building its reactor around 2026, hoping to deliver power by decade’s end. Even so, it hasn’t attained regulatory approval just yet.

If Wyoming will be the first, there are signs that it won’t be the last. In neighboring Montana, state legislators recently approved a study for converting one coal plant to nuclear. That plant, situated in the coal mining town of Colstrip, currently faces its imminent end as nearby Oregon and Washington plan to ban coal power by 2025.

In West Virginia, once coal’s citadel, the state government eliminated its old ban on nuclear power plants. Nationally, the recently enacted Inflation Reduction Act offers tax credits for nuclear projects in communities with retiring coal plants—something that will certainly increase interest in conversions.

“Are all of these sites going to get nuclear power plants? Probably not,” says White. “But is this a really good way for people to start the conversation on what are potential next steps, and where are potential sites to look at it? I think that’s a really cool opportunity.”

The Conversation (8)
Christopher Aoki
Christopher Aoki03 Oct, 2022

Rod Adams asks, “Given the time it takes to grow trees, are biomass

burning plants really carbon-neutral?”. Excellent question; here's an

example to illustrate the issue.

BBC posted a story today about using biomass-burning power plants

as a nuclear-free, 100% renewable energy source. As the BBC story

points out, the "renewability" of trees fueling such plants is a huge

distortion when the trees are logged from old-growth forests and

shipped to mills for conversion to sawdust for export as “renewable


Source: BBC News (03 Oct 2022)

Article: Drax: UK power station owner cuts down primary forests in Canada

Authors: Joe Crowley and Tim Robinson, BBC


See also:

Panorama's The Green Energy Scandal Exposed is on BBC One at 20:00 on Monday 3rd October and on iPlayer afterwards

Christopher Aoki
Christopher Aoki29 Sep, 2022

Thanks Rod Adams for setting the record straight on SMR development and deployment.

There's more on the subject of coal=>nuclear plant decarbonation in "Atomic Insights"

a blog maintained by Rod and business partner Valerie Gardner:

Article: A Path from Coal to Nuclear is Being Blazed in Wyoming

Source: Atomic Insights

Author: Valerie Gardner


The blog mentions this additional item of interest:

In December, 2020, Staffan Qvist, Paweł Gładysz, Łukasz Bartela and Anna Sowizdzał published a study that looked at the issue of retrofitting coal power plants for decarbonization in Poland.  They published their findings in Retrofit Decarbonization of Coal Power Plants—a Case Study for Poland, showing that decarbonization retrofits worked best using high-temperature small modular reactors to replace coal boilers.


Both the blog article and the paper from Polish scientists are worth checking out!

Maury Markowitz
Maury Markowitz28 Sep, 2022

I find it difficult to believe there are any savings in re-using existing coal sites. It seems less difficult to believe it is cheaper to abandon them and re-build.Turbogeneration machinery tends to be relatively customized to the plant layout. Rerunning the plumbing for a new "boiler" (of any form) is a non-trivial prospect, and given the price of the entire generation side is perhaps 15% of the total capex, it seems highly unlikely those costs are less than simply building new machinery. It is also the case that such systems wear out and become increasingly expensive to maintain, and as the plants in question are generally decades old, it is almost certainly the case that a new plant's opex will offset any possible savings in capex. And the other savings, decades-old buildings, roads and control systems? Hmmm, these do not strike me as adding up to anything beyond a rounding error.

There's the possibility that siting requirements are eased, but I'm sceptical of that as well. Siting requirements for coal vs. nuclear are different, but even if one assumes that these could be harmonized (which I'm sure they'll get to Real Soon Now) it is also the case that they have changed in the decades since the plants were originally built. I'd be surprised if a portion of the sites are no longer available to build even a coal plant on given new regulations and/or changes in city layout.

If there was any potential savings in building a new plant on existing hardware, one would expect to see such examples in the past 50 years. I cannot think of any. In contrast, I can think of any number of plants, say Douglas Point, which were left intact while entirely new facilities were built beside it.

It all sounds nice, but seems to be extremely unlikely given that the part they propose to save is the cheap part and the part they propose to add would be better off with new kit.