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.
