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Honey, I Shrunk the Nuclear Reactor! (3 years later)

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Matt Chester's picture
Energy Analyst, Chester Energy and Policy

Official Energy Central Community Manager of Generation and Energy Management Networks. Matt is an energy analyst in Orlando FL (by way of Washington DC) working as an independent energy...

  • Member since 2018
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  • Feb 16, 2022

What follows below is an article I shared into the Energy Central community three full years ago (where does the time go?), which can be read here

I'm republishing the text of this below because it generated some terrific conversation in the community back in 2019 and I'm curious to see how the reaction and conversation regarding this topic has changed in those three years. What updates to the path this technology has taken should be accounted for? Where were there hopes or expectations that started to fall short? Is your opinion different than it was three years ago?


Honey, I Shrunk the Nuclear Reactor!

I immediately apologize for that lame title, but I wanted to take a moment to talk about the ability that the R&D into increasingly smaller nuclear reactors might have in the future of a decarbonized energy mix. 

The U.S. Department of Energy has been touting their efforts into Advanced Small Modular Reactors (SMRs) as a key part of the future of clean and affordable energy. 

NuScale Reactor Building

According to DOE:

Advanced SMRs offer many advantages, such as relatively small size, reduced capital investment, ability to be sited in locations not possible for larger nuclear plants, and provisions for incremental power additions. SMRs also offer distinct safeguards, security and nonproliferation advantages.

The Department has long recognized the transformational value that advanced SMRs can provide to the Nation’s economic, energy security, and environmental outlook. Accordingly, the Department has provided substantial support to the development of light water-cooled SMRs, which are under licensing review by the Nuclear Regulatory Commission (NRC) and will likely be deployed in the next 10-15 years. The Department is also interested in the development of SMRs that use non-traditional coolants such as liquid metals, salts, and helium because of the safety, operational, and economic benefits they offer.

What's excited me about these SMRs is that the economics can flip around and make nuclear more accessible and reasonable as a solution. The battle that's been going on over Vogtle, the only nuclear construction project in the United States that's been inundated with delays and a ballooning budget, have demonstrated that the prospect of building new nuclear plants at current sizes seems farfetched. While the economics of keeping existing nuclear going can compete with and often beat building new renewable energy, without the ability to build new nuclear there's an inherent (and declining) ceiling on how much nuclear can contribute to the future decarbonized grid. BUT, these SMRs offer the ability to overcome those economics, while presenting increased safety (since they are smaller and don't need as extensive protections as their larger cousins) and might help overcome a lot of the knee jerk reaction people have to nuclear.

While these SMRs have been discussed for a while now, what prompted me to post this topic was a new effort I recently came across: "Nuke on a truck." The idea is similar-- dropping down the size of nuclear plants in great steps, to the point they could fit on the bed of a truck and function as a nuclear battery. Some choice quotes from this article include:

Picture this: a remote Army base in frigid Alaska, some 150 miles from the Arctic Circle.

Taking risk is necessary for growth. This series profiles the region's entrepreneurs, policymakers, scientists and others who have embraced challenges and incorporated new ideas – sometimes the kind that seem a little crazy – into their plans. 

“Most of the year there’s no sunshine,” said Yasir Arafat (his real name), Westinghouse’s technical lead for eVinci. “Wind turbines would ice up. The only thing that works there is diesel.”

The diesel must be replenished every six months. The fuel trips command resources and have national security implications.

The eVinci idea would function like a nuclear battery. “Once it’s plugged in, it will work for 10 years straight,” Mr. Arafat said.


Microreactors will have to prove that they are not just a scaled down version of a large nuclear reactor — either in design or in deployment.

To think up the eVinci model, Westinghouse drew inspiration from nuclear reactors that power space ships, as those are “probably the only nuclear reactor concept that run autonomously, without any operators,” Mr. Arafat said.

The concept also requires more advanced materials to withstand temperatures up to 600 degrees Celsius, nearly twice the heat inside an AP1000 reactor vessel.

The cost and timetable would have to be selling points for microreactors.

Commercial operations of these units wouldn't begin until 2024, but again the idea that nuclear reactors-- if done correctly-- could fit into a DER type model and be located close to where they're needed, while providing the baseload generation needed to pair with renewables until storage technology can fill in those gaps, greatly excites me. 


What do you think?

Bob Meinetz's picture
Bob Meinetz on Feb 16, 2022
Joe Deely's picture
Joe Deely on Feb 17, 2022

Where were there hopes or expectations that started to fall short? Is your opinion different than it was three years ago?

Yep time flies... In the intervening three years we have seen: 

 - 28 GW of coal has retired since 2019 

 - CO2 in electric sector dropped from 1,764 MMT in 2018 to about 1,600 MMT in 2021

 - Wind and solar generation grew by 170 TWh

 - further confirmation from Vogtle  that "large nuclear" just won't work in the US. 

- 5 more large nuclear units retire

- a significant pushback in the timeframe when first of these reactors might be deployed in US. You mentioned 2024 in your article.

NuScale’s SMR is a mature technology and we will be ready to provide modules to clients by 2027. We are not in the conceptual stage of development, but rather finalizing the design to prepare for the manufacture and construction of our first VOYGR power plant in the United States. By the end of this decade, a NuScale VOYGR power plant will become part of the Carbon Free Power Project (CFPP), an initiative spearheaded by the public power consortium Utah Associated Municipal Power Systems (UAMPS). The first module will be operational by mid-2029 with remaining modules coming online for full plant operation by 2030.

A lot more retirements are going to happen this decade before the first of these units is fully operational.

    - 48 GW of planned coal retirements - actual number will be much higher.

    - 19GW of planned NG retirements

    - 3 more nuclear units have planned retirements

So my updated take is:

  1. A lot of work needs to be done between now and 2030 to continue to reduce the CO2 associated with electric generation in the US. SMRs will provide no assistance in this time frame.
  2. Hopefully, SMRs will ramp up quickly after initial deployment and we will see them help replace the remaining few coal units in the US by the mid 30s and helping to start replace NG by the late 30s.
Michael Keller's picture
Michael Keller on Feb 21, 2022

Unless the SMR’s are heavily subsidized like green energy, competitive economics do not favor small reactors. The historical route to more cost effective power plants lies with larger output and greater efficiency. The SMR’s fail on both counts.

Perhaps a more serious problem for SMR’s is the immense financial risk associated with licensing the facilities. There is no compelling reason to believe the severe cost/schedule problems of large reactors will not also be present with their smaller cousins. These problems are directly tied to the stunning complexity of the licensing process that extends deeply into design, manufacturing, construction, and operation of US nuclear plants. 

Audra Drazga's picture
Audra Drazga on Feb 18, 2022

This was one of our most popular posts a few years back - so glad to see it back!  I am looking forward to reading any new insights that are added by community members on this topic. 

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