Best estimates for when nuclear can begin to make a significant contribution to the US grid are still in the mid-2030s.
Nevertheless, there are a number of projects underway, each of which could be a puzzle piece.
The most consequential current developments are the restarts of existing, 50 year old plants, which could begin significant generation near term.
The other builds skew on the “demonstration” and “research” side, and have longer time lines.
There persists this unfounded view, even among some very smart people, that somewhere, an evil cabal of blue haired, green-addled hippies are preventing the massive rollout of the nuclear plants that will save us. The biggest obstacles to nuclear are today what they have always been – financial.
For added context, see my posts here and here.
Nuclear Hazelnut (Jenifer Avellaneda) on X:
Did you know there are actually 5 nuclear reactors under construction in the United States right now?
And that doesn’t even include major reactor restarts… Let’s break them down..
Hermes – @KairosPower
Oak Ridge, Tennessee • 35 MW test reactor • Fluoride salt–cooled high-temp reactor • Uses TRISO fuel • NRC construction permit issued in 2023 • First advanced non-light-water reactor under construction in the U.S. in decades Goal: Demonstrate tech before commercial deployment.
Fun fact: It’s being built near the birthplace of the Manhattan Project.
Hermes 2 – Kairos Power
- Two additional test reactors
- Same 35 MW design
- Approved in 2024
- Designed to accelerate learning before commercial rollout
MSR-1 – Natura Resources
Abilene Christian University, Texas • Molten Salt Reactor • ~1 MW • NRC construction permit issued in 2024 • Research + demonstration reactor Fun fact: This is one of the 1st university-associated advanced reactor builds in modern U.S. history!!
Aalo-X – @AaloAtomics
Idaho • 10 MW modular reactor • DOE Reactor Pilot Program participant • Experimental demonstration unit • Groundbreaking completed Designed as a factory-manufactured microreactor platform. Fun fact: The company is targeting first criticality around 2026!!!
atrium – @TerraPower
Kemmerer, Wyoming (at a retiring coal plant site) • Sodium-cooled fast reactor • 345 MWe • Integrated molten salt energy storage • Non-nuclear construction underway •
Target early 2030s
Fun fact: It can ramp output to 500 MWe using thermal storage.
Palisades Nuclear Plant –@holtecintl (Michigan)
~800 MWe PWR • Shut down in 2022 • Now undergoing refurbishment for potential restart in 2026 This would be the first restart of a fully closed commercial nuclear reactor in U.S. history!! Fun fact: It’s receiving federal support because policymakers now see nuclear as essential for grid reliability & clean energy goals
Crane Clean Energy Center –
@CEGCleanEnergy (Pennsylvania)
~837 MWe PWR • Closed in 2019 • Restart effort underway to serve growing electricity demand, including data centers Yes, formerly known as Three Mile Island.
Same Unit 1 that operated safely for decades. One of the most symbolic nuclear comebacks in U.S. history
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Worth noting: Here is Kelly Trice, President of Holtec International, who is supervising the Palisades rebuild, talking about the subsidies that have been crucial to getting that project to pencil out.
Virtually all nuclear energy promoters, are in line with the vast majority of Earth’s other 8.25+ billion humans, who continue to assume that we still have at least 20 years left to turn this ‘Titanic’ around using their favorite nuclear technology. They have become masterful in excluding the following warning from their consciousness.
UN chief: World has less than 2 years to avoid ‘runaway climate change’ (TheHill)
* This statement was made 7.4 years ago.
And thee is in the line that there is one and only one way. Things are not mutely exclusive, and nukes are often, usually, the only option to provide non polluting backup. Should have started years ago. Median build time in China, 41/2 years. Korea built 3 over 13 years. It can, CAN, be done. Apart from dumping on nukes, your post is correct.
Besides being unacceptable in soooo many ways, and impossible for democratic countries to build in anything less than years past too-long deadline and billions over too-big budget, nukes are uniquely UNsuited for providing backup.
Peter, I love that you subtly, sardonically, dump on nukes.
I get it that they build things faster in China and Korea. It’s concerning that the approaches being taken in the US don’t seem to be accelerating anything. Bill Gates has been trying to get this done for most of 20 years, no shortage of funding, and he’s still not there.
The US’s perverse private funding hodge-podge (with investors seeking taxpayer or ratepayer coverage for cost overruns) means is cannot replicate what China is doing.
This is not a technical issue, but a socioeconomic one.
One thing I don’t know: What’s the carbon payback period for China’s nukes?
The idea of nuclear power is great on paper, but in practical experience, we have had many challenges in the USA, most importantly in project execution and economics. I am quite well informed on the history of this.
What bugs me is the all too glib assertions of those who say “Why don’t we just build nuclear power?” as if it was as easy as going down the street to the nuclear plant store and buying a nuclear plant.
I posted on this a few weeks ago, and the money quote is:
““This is the greatest capitalist system in the history of mankind,” said Mike Scott, founder of private-equity firm Pelican Energy Partners. “We have so many greedy people who want to make money, and if they could make money today building a nuclear plant, they’d be doing it.””
https://thinc.blog/2026/01/29/trump-official-nuclear-industry-greedy/
As the world cooks, let us consider what is needed, not just what we want.
Sorry, but that really comes across as a deepity.
Whatever a ‘deepity’ is, my concern is for the ecosphere and what lives it. Not hippi dippy wishful thinking.
Right back atcha. I consider nothing else. Nukes are—face it—slow to build, expensive, a security risk, centralized power that is nothing but a hindrance to the effort to prevent catastrophic warming.
They can’t be safely built near people; building them far away takes up forestland we should be cutting down for solar farms so the anti-renewable fanatics have something truthful to whine about for a change. They can’t be built away from water but disastrously heat up streams and rivers. After Fukushima they can’t be built near oceans and I hear there’s no water on the moon. Plus, Amazon is out of extension cords that long. No place on Earth, no place anywhere else.