But beyond safety, the size and complexity of nuclear plants is intimidating and cumbersome. Think how the cooling towers of the Springfield Nuclear Power Plant loom over the town and it’s owner, Mr. Burns, is so rich he can block out the sun. (Don’t worry, more Simpsons references on the way).

We’re talking about custom-built, $10B+ megaprojects, layered with decades of regulatory oversight, all feeding into massive centralized power grids. These plants are expensive, slow to build, and politically fraught. In recent years, they’ve also been competing with large-scale renewable projects (wind, solar, hydro, etc.) for funding, approvals, and public goodwill.

The result? Tons of misinformation, increasing utility costs for consumers, slow energy innovation, and unlikely political alliances in the U.S.

And yet, nuclear is quietly coming back into vogue. One of the main reasons is the rise of microreactors.

Without diving deep into the physics, microreactors work on the same basic principle as traditional nuclear power (splitting atoms to release heat) but at a much smaller scale. Inside the reactor, nuclear fuel slowly undergoes fission, producing heat that’s carried away by gas, metal heat pipes, or solid materials rather than water. That heat is then converted into electricity using familiar systems like turbines or generators.

What makes microreactors different is how they’re engineered precisely to avoid the pitfalls of conventional nuclear.

A different kind of fuel.
Many microreactors rely on TRISO fuel, one of the biggest enablers of this category. Instead of long metal fuel rods (like the ones Maggie Simpson plays with), TRISO fuel is made up of millions of tiny particles, each about the size of a poppy seed. At the center of each particle is a kernel of uranium fuel, wrapped in multiple protective layers, including a ceramic shell that traps radioactivity and withstands extreme heat. Each particle is essentially its own miniature containment system, meaning the fuel remains stable even if the reactor is damaged.

Passive cooling.
Microreactors are designed so heat naturally dissipates through physics - not pumps or rapid human intervention. In most designs, it’s effectively impossible for a traditional meltdown to occur. They’re built to pass the “walk-away” test: if everything shuts down, the reactor still stays cool and safe on its own.

Factory-built, not one-off.
Conventional nuclear plants are custom projects built on site by massive crews, often constructing the first and only reactor of their careers. Microreactors instead are built to a common specification in factories, concentrating expertise, quality control, and expertise in one place. Think riding in a Toyota versus a go-kart your neighbor welded together.

Portable and dependable.
Because microreactors can be transported by truck or plane, they can be deployed exactly where power is needed: off-grid communities, AI data centers, hospitals that lost power in a hurricane, or Mars.

Safer because they’re small.
Even setting design features aside, size matters. Microreactors contain far less fuel and generate far less decay heat than gigawatt-scale plants. In a true worst-case scenario, there simply isn’t enough energy or radioactive material to produce a Chernobyl- or Fukushima-scale disaster. You can’t scale down risk perfectly, but you dramatically limit the downside.

Also, unlike the tropical, futuristic micro-hostel-meets-reactor image at the top of this article (Dan… told you it was confusing), many designs are intended to be installed underground, further reducing exposure pathways.

Radiant Nuclear’ Kaleidos is a high-temperature, gas-cooled microreactor that produces 1.2 MW of electricity and heat. Packaged inside a single shipping container, it’s designed to run five years without refueling. Each container replaces a diesel generator that would consume roughly 1,200 liters of fuel per day.

In late 2025, Radiant raised $300 million and announced plans to open a factory with the goal of producing 50 reactors per year by 2028. Their early customers are exactly who you’d expect: military bases, disaster-response agencies, and remote industrial sites.

Radiant’s origin story is cool too. Founder Doug Bernauer, then an engineer at SpaceX, was thinking about how humans might power a permanent presence on Mars. Solar alone wouldn’t cut it. Nuclear kept emerging as the only viable option. As he dug deeper, Bernauer had a second realization: if compact, resilient nuclear systems were essential for space, they might be just as transformative here on Earth. So, he left SpaceX in 2020 to start Radiant.

For all the excitement, it’s important to be clear about where this industry actually is.

Today, there are a handful of operational reactors and none that are supplying electricity to civilian customers. A number of designs are scheduled to reach first operation in the next few years - mostly through government pilot programs. Seems like we’re past scientific viability, and now face challenges around execution and deployment:

Also, as history has shown us, many things that have been said to be fail-safe in the past might come with unforeseen consequences. But this is the first new nuclear design approved in decades, which is clearly an important achievement and it might be a long time before humans have another window of opportunity to deploy similarly innovative energy tech. We, along with many others, believe microreactors should be fast-laned with the appropriate and thorough checks for safety. The good news is that they’re getting a lot of support. As Dr. Hossenfelder says, “small modular reactors might not yet produce electricity, but they’re generating a measurable field of political enthusiasm.”

In many ways, microreactors land squarely in the Hell Yeah sweet spot: moonshot technology, sustainability, Mars, etc. Also, there’s legitimate concern about long-term risk and if costs will ever come down to be competitive.

But what really gets our atoms splittin’ about microreactors is something simple: we need more power to do all the cool shit we want to do. Like a lot more power than we’re able to produce. Microreactors as a product might be able to help. But also, the smaller size and achievable financing opportunities enables more entrepreneurs to come into the energy space and figure it out.

For decades, energy debates have revolved around massive projects and ten billion dollar tradeoffs. Microreactors can change the question to be about logistics and deployment, which feels more tractable and solveable. Groups like Radiant show that awesome entrepreneurs are attacking the problem head-on in ways that rethink the problem from the ground up. They are breaking through regulatory, financial, and public opinion barriers via “in the box” creative thinking.

So yeah. We’re watching this one closely. Hell yeah!

Radiant Nuclear Homepage

Radiant Nuclear YouTube

NASA and DOE to Develop Lunar Reactor by 2030

ScienceDirect Microreactor Overview

Yahoo! Finance Article on Microreactors