First — it was modular furniture.
Today, we have modular homes — absolute game-changers when it comes to buying real
estate.
Could Modular Nuclear Reactors have the same revolutionary impact in the clean energy market?
Their low-cost, flexible designs make them powerful contenders in the world of clean
energy.
So are we going to see things like nuclear powered airplanes, and cars in the near future?
What about little tiny modular reactors powering our homes?
We thought these questions and this very interesting technology deserved a deeper dive today on
Two Bit Da Vinci.
For some, the mere mention of nuclear power conjures up nightmares of mushroom clouds
and three-eyed fish.
But nuclear energy has proven vital in the quest for carbon-free energy production.
Since emerging in the 1950s, Nuclear energy has increased by over 2,000%.
(World Nuclear Association, 2021).
In the US alone, over 90 nuclear power stations contribute one-fifth of the Nation’s electricity.
Globally, Nuclear reactors accounted for over 10% of electricity generation in 2019.
(Ferrell, 2020), (Silverstein, 2021)
Best of all, nuclear power is virtually carbon-free.
One study even suggests that the nuclear reactors in Illinois can produce more carbon-free energy
than all of the windmills in California!
Those sound like fighting words!
(Silverstein, 2021)
Nuclear energy, unlike other green energy, isn’t susceptible to intermittency, weather
patterns, or changes in the amount of sunlight, making it a reliable baseload power source.
(Silverstein, 2021)
And yet... nuclear energy production has been steadily declining since the mid-90s. (Ferrell,
2020)
The rise of wind and solar has partly contributed.
But nuclear reactors are big and expensive — a new nuclear power plant in the US can
cost up to $6,000/ kW, trailing behind its arch-rival, natural gas, which costs less
than a grand per kW.
(Schlissel, 2008) Plus, not every region on the planet has the
infrastructure to build those massive, hour-glass-shaped towers.
We can’t all be Springfield, wherever you are!
But — what if there was a way to have all the benefits of nuclear power without the
cost and size?
Introducing the Small, Modular Reactor!
We made a video about a modular housing company called Boxabl, which we’ll link here, and
how their ability to automate, and create walls and homes on an assembly line can really
drive down costs.
Sure there are challenges, like with all things, but what if, instead of building massive onsite
nuclear power plants, we could crank them out smaller on an assembly line?
So, when we say “small,” how small are we talking?
The International Atomic Energy Agency defines a “small” reactor as one that produces
300 MW of electricity or less.
These systems, called SMRs are also designed and built inside factories using modular technology.
Some reactors can produce as little as 15 MW.
(World Nuclear Association, 2021)
Like their larger siblings, small modular reactors use Nuclear Fission to split atoms,
heating water, producing steam, and turning generators to make electricity.
(Michaels, 2021)
We’ve actually done a whole video on a different type of reactor that uses nuclear fusion if
you’re interested in checking that out.
This is the holy grail of energy generation, but alas it’s not quite ready for prime-time
just yet.
There are four main varieties of SMRs.
These are the condensed versions, BUT if you want us to dive deeper into any of these topics,
let us know in the comments!
So, the four types of SMRs are...
Light Water reactors — which use normal water, as opposed to heavy water (deuterium
oxide D2O), as both its coolant and neutron moderator.
Fast-neutron reactors in which the fission chain reaction is sustained by fast neutrons
(carrying energies above 0.5 MeV or greater), as opposed to thermal neutrons used in thermal-neutron
reactors.
There are graphite-moderated high-temperature reactors.
And finally, reactors that use various kinds of non-light water coolants such as gas, liquid
metal, or molten salt reactors (MSRs).
(World Nuclear Association, 2021) (Department of Energy, 2021)
With the average nuclear plant producing between 600 MW and 1.5 gigawatts of power, SMRs are
indeed pretty small.
Which begs the question…
What's the point?
(Department of Energy, 2021)
Well — what these reactors lack in size they make up for in a few key areas.
A 1,000-megawatt facility needs about 1 square mile of space.
They also need to be built on-site, which can lead to delays due to things like bad
weather, which inflate budgets.
(Department of Energy, 2021) (Conca, 2018)
Georgia's Vogtle nuclear plant expansion has already fallen years behind schedule, spilling
billions over budget — and it’s facing even more delays as we speak.
(Spector, 2019)
SMRs on the other hand have a much smaller footprint.
And best of all, they’re built entirely within a controlled factory setting and installed
piece by piece.
Think of it like high-stakes, nuclear legos.
Factory construction avoids things like weather delays — allowing faster build times.
Factory settings also allow for better oversight, improving construction quality and efficiency.
(World Nuclear Association, 2021)
Deciding where to build a massive reactor can pose challenges.
Acreage, access to water, grid requirements, the list goes on.
For smaller, isolated regions, massive power stations aren’t always practical.
Because SMRs are built in factories and then shipped, they can bring carbon-free energy
to regions that otherwise wouldn’t have that option.
(Silverstein, 2021) (Department of Energy, 2021)
Estonia, for example, was kept reluctantly behind the Iron Curtain for five decades before
gaining independence in 1991.
Today, they still remain gripped by Moscow’s energy grid.
Kalev Kallemets, chief executive of Fermi Energia, an Estonian startup, sees SMR designs
as a means to energy independence.
(Michaels, 2021)
For anyone who hasn’t been to Estonia, trust me, you got to add it to your travel list.
Winter or summer, Old Town Tallinn is one of my favorite places!
While individual SMR reactors produce up to 300 MW, they’re designed to work in parallel.
Start small with just one unit, keeping costs low, and only add more if or when your needs
increase.
(Department of Energy, 2021) (World Nuclear Association, 2021).
Plus, if one module goes down, the rest keep plugging away while the defective one is repaired
or replaced.
(Silverstein, 2021)
They can also be linked to energy sources like wind or solar.
The nuclear reactions that take place also create lots of cool residual benefits like
turning water into hydrogen for fuel, or even creating potable drinking water.
(Silverstein, 2021)
The ever-increasing cost of building and maintaining conventional reactors has stifled the growth
and development of new nuclear plants since the 1980s.
Not to mention winning the hearts and minds of the local public, and conforming to ever
stricter regulations.
A 2011 report by the University of Chicago Energy Policy Institute suggested that small
reactors could significantly offset the financial risk associated with full‐scale plants.
Smaller size, lower construction cost, passive safety systems (more on those in a minute)
— all of these factors lead to easier financing compared to larger plants (World Nuclear Association,
2021)
A huge bonus is that these reactors can easily be retrofitted into brownfield sites in place
of decommissioned coal-fired plants (World Nuclear Association, 2021).
One key component of lowering the cost for SMRs is what’s called “economy of series
production,” or “economy of sequence.”
Basically, the more dialed in the system for producing SMRs becomes, the more units can
be built in a smaller amount of time, with cost-saving measures at every step of the
process, bringing down the overall cost.
This is in contrast to “economy of scale,” which some see as potential roadblocks for
SMRs, but we’ll dive into that in a bit.
Because of their compact size, SMRs can operate safely with reduced need for thick shielding,
complex safety systems, and intensive maintenance regimens.
(Michaels, 2021) A 2010 report by the American Nuclear Society
showed that many safety provisions in large reactors are not necessary for the small designs
because of their higher surface area to volume (and core heat) ratio.
(World Nuclear Association, 2021)
SMRs are also built below grade — underground or underwater — reducing vulnerabilities
to human-made sabotage and natural phenomena like earthquakes or tsunamis.
(Department of Energy, 2021) (World Nuclear Association, 2021)
They use passive as opposed to active safety systems — like electrical pumps and AC power
grids.
Some systems will simply involve the core resting in a pool of water — hence Light
Water SMRs.
Other systems will use different solvents, like molten salt, similar to solar arrays.
These run hotter than water reactors but with less pressure and no pipes or pumps.
A number of government agencies and private companies have already devoted millions of
dollars to SMR development
In fall of 2020, the US Department of Energy awarded $210 million to 10 projects to develop
SMR technology.
(Michaels, 2021)
Leading the charge is the Oregon-based NuScale, whose feisty 60 MW reactor requires only 1%
of the space required by conventional reactors (Levitan, 2020)
NuScale plans to install 12 MW SMRs to build a 720 MW nuclear power plant that’ll run
roughly 20% cheaper per megawatt than larger competitors.
(Ferrell, 2020)
Other top US SMR companies include GE, which has two current projects in development — a
slimmed-down water-cooled reactor, as well as the Natrium Project developed in collaboration
with the Bill Gates-backed startup TerraPower LLC, which uses molten salt.
(Silverstein, 2021) (Michaels, 2021)
So at this point, you might be thinking — “sounds great.
But…
What are the potential drawbacks?”
As with all tech, SMRs aren’t entirely flawless.
While SMRs tote lower costs and greater efficiency, some opponents question these potential outcomes,
in particular, because of what's known as “economies of scale.”
Basically , a large reactor that produces three times as much power as an SMR does not
need three times as much steel or three times as many workers — so it costs less in the
long run (Makhijani, 2021)
Advocates for SMRs argue that modularity and factory manufacture would compensate.
But for SMRs to truly be worth it, their price per kilowatt would need to compete with larger
reactors or other types of energy — namely that old rival, Natural Gas.
There’s also concern over the design of pressurized water reactors.
The massive heat exchangers that convert water into steam are prone to premature breakdowns.
In the last decade, such problems led to the permanent shutdown of two reactors at San
Onofre, right here in San Diego, and one reactor at Crystal River, in Florida.
(Makhijani, 2021)
Then, of course, there’s the concern that looms over all nuclear energy — Radioactive
Waste — which can have half-lives of tens of thousands of years!
So if your mind was conjuring a new wave of nuclear-powered cars, that only needed to
be filled up every 20 years, well I have some bad news.
While SMRs have dramatically reduced the size and complexity of nuclear reactors, there
is still a certain size required to maintain the nuclear chain reaction, and even be worth
building.
Maybe in the future, we’ll have airships that fly around for years running on nuclear
power, but for now, this new wave of SMRs are still squarely positioned to compete with
stationary grid energy.
With that said, there are dozens of SMR projects currently underway all over the world.
If they can truly make good on their potential, we could see a new wave of carbon-free power
bringing energy to places throughout the world that might not have the option otherwise.
But what do you think?
Are small, modular, reactors the way forward for Nuclear power?
Sound off in the comments section.