To gasoline the insatiable vitality urge for food of synthetic intelligence, tech corporations are going massive on small nuclear reactors.
Final week, each Google and Amazon introduced agreements with corporations which are growing small modular reactors. These reactors would produce much less energy than present reactors, and lots of designs embody various kinds of gasoline or coolants, plus further security options.
The bulletins have amplified the thrill round small modular reactors, which have attracted rising consideration lately, given the necessity for clear vitality that gained’t contribute to local weather change. A wide range of corporations have sprung as much as meet the necessity, producing a cornucopia of proposed designs for small modular reactors.
“When you mix the necessity for resilient energy with the necessity for clear energy and the rising availability of those designs, you get an awesome upswing in curiosity,” says nuclear engineer Kathryn Huff of the College of Illinois Urbana-Champaign.
In the meantime, the U.S. authorities has been supporting the event of small modular reactors, additional feeding curiosity.
So what’s on the horizon for this potential new nuclear era? We break down the massive questions on how and why nuclear reactors are going small.
What are small modular reactors?
Business reactors in america usually produce round a billion watts {of electrical} energy. Small modular reactors would produce lower than a 3rd of that.
Conventional nuclear crops require large funding up entrance, a hurdle that has stalled the constructing of latest reactors in america for many years. The primary newly constructed reactors constructed within the nation in 30 years — two in Waynesboro, Ga., that switched on in 2023 and 2024 — price round $30 billion. The development was years delayed and billions over finances.
By pivoting to smaller reactors, corporations and coverage makers purpose to propel the proliferation of nuclear energy, which is touted as a supply of dependable vitality free from greenhouse fuel emissions.
Plus, since smaller reactors produce much less energy, much less residual warmth must be eliminated to soundly shut down the reactor within the occasion of an accident, simplifying security programs.
With smaller reactors, Huff says, it’s simpler to construct elements offsite in a manufacturing facility and ship them the place they should go, somewhat than customized constructing them from uncooked supplies on website. “The extra you’ll be able to construct these reactors like airplanes somewhat than airports, the cheaper it’s typically going to be.”
What’s fueling curiosity in these reactors?
In america, nuclear energy presently boasts assist from each Democrats and Republicans, an uncommon state of affairs that has allowed the sector to thrive, whilst political powers shift. “Previously 10 years, it’s been fairly constant and rising assist, and I believe it’s a giant deal,” says nuclear engineer Todd Allen of the College of Michigan. Nuclear vitality is a pillar of the Biden administration’s plan to realize local weather objectives.
In the meantime, AI’s insatiable want for vitality has created an issue for tech corporations that don’t need to be seen as local weather change baddies (SN: 12/11/23). Google introduced October 14 that it could buy vitality from small modular reactors to be constructed by Kairos Energy, which goals to have reactors beginning up within the 2030s. And on October 16, Amazon introduced an funding in the corporate X-energy and agreements with utility corporations in Virginia and Washington state to determine small modular reactors.
And it’s not simply massive tech that’s . A 2023 settlement between X-energy and the chemical firm Dow introduced a small modular reactor to be constructed at one in all Dow’s websites.
The U.S. Division of Power has been funding growth of small modular reactors. On October 16, the DOE introduced $900 million in funding for deployment of small modular reactors. And each X-energy and the Invoice Gates–backed TerraPower are constructing demonstration initiatives with DOE assist.
Conventional nuclear crops nonetheless play a task for the foreseeable future. On September 20, Microsoft introduced a deal to restart the Three Mile Island energy plant close to Middletown, Pa., which shut down in 2019. (Sure, that Three Mile Island. After the notorious partial meltdown in 1979, one other reactor on the plant continued working (SN: 4/7/79).)
“Firms that historically shied away from mentioning nuclear vitality as a part of their portfolio, as a result of they had been involved about public perceptions and potential coverage blowback, are coming ahead and embracing it,” says nuclear engineer Koroush Shirvan of MIT.
How is the expertise completely different from present reactors?
Business nuclear reactors in america typically use the identical sort of uranium gasoline and are cooled by water. However many small modular reactor designs break that mildew.
The uranium utilized in reactors is enriched to incorporate extra of the related selection, or isotope, of uranium, U-235. Present reactors use uranium enriched to a couple p.c U-235. Many small modular reactors would use uranium enriched as much as 20 p.c U-235, generally known as high-assay low-enriched uranium, or HALEU (SN: 7/3/24). The gasoline permits small modular reactors to run extra effectively than a reactor with typical gasoline. The USA doesn’t produce HALEU commercially in important portions, however efforts have begun to rev up, in anticipation of the necessity.
Some reactors use gasoline that’s completely different in additional apparent methods, too. X-energy and Kairos, for instance, will use TRISO gasoline: encapsulated, poppy seed–sized pellets of uranium contained inside bigger spheres of fabric, every the dimensions of a tennis ball. The gasoline is “extraordinarily strong to very excessive temperatures for very lengthy instances,” Huff says. “It provides you this further layer of protection.”
The coolant, the medium used to switch warmth from the reactor to the ability era portion of the plant, is an important selection as properly. TerraPower makes use of liquid sodium, Kairos makes use of molten fluoride salt, and X-energy makes use of helium fuel. Totally different coolants can have benefits corresponding to an elevated effectivity of warmth switch, or eliminating the necessity for pressurized vessels.
The designs additionally incorporate security options that don’t require human intervention to kick in, serving to to make sure the reactor can shut down safely in an emergency. They harness easy physics, for instance, counting on gravity, stress variations or the pure convection of liquid coolant, to chill the core.
What’s subsequent?
The idea of small modular reactors has been round for a few years, however earlier makes an attempt haven’t panned out. Even latest efforts have stumbled. The reactor firm NuScale was set to supply the primary business small modular reactors in america, as a part of a challenge in Idaho, however the challenge was cancelled in 2023 after prices ballooned.
Now, with massive tech corporations throwing themselves into the combo, proponents are hopeful that small modular reactors can be getting off the bottom quickly.
“You’ll be able to see the momentum constructing,” Allen says. “It doesn’t imply you’re going to have a brand new business model this yr, however it’s additionally far more stuff occurring that feels actual than we’ve seen in nuclear for a really very long time.”
