Radiant Wins First-Ever DOE OK For Full-Power Microreactor As Nuclear Stocks Crash To Multi-Year Lows

For the first time ever, Washington has signed off on a commercial nuclear microreactor running at full power. On Wall Street, nobody seems to care.

On Thursday, the Department of Energy approved the Documented Safety Analysis (DSA) for LA-based Radiant's Kaleidos, a 1-megawatt, truck-transportable reactor that is now sitting inside the DOME test bed at Idaho National Laboratory. According to the company, it is the only microreactor design to secure DOE safety approval covering operation at power, as opposed to the zero-power criticality tests that every other entrant in the DOE pilot program has run so far.

And yet the stocks most levered to the small modular reactor story are trading like the industry is going out of business: Oklo (OKLO) closed Friday at $25.25, down 86% from its October 2025 peak and at its lowest since April 2025, while NuScale (SMR) is down 89% and sitting at a price last seen in April 2024.

Regular readers know we have been tracking the microreactor buildout since well before it was a meme (and long before it stopped being one), so let's take a closer look at what Radiant actually got, where the rest of the pack stands, and why the market has decided none of it matters, at least for now.

What Radiant Actually Won

The DSA approval is the step that comes after DOE signed off on Radiant's preliminary safety analysis back in February. With it in hand, Radiant moves into DOE's Readiness R