From theory to reality

Recently, I spent an afternoon at Kairos Power's Hermes construction site in Oak Ridge, Tenn. What I saw there was not a rendering, not a licensing presentation, not another panel about the future of advanced nuclear. I saw dozens of pilings built to NQA-1 standards. I saw seismic isolators ready for installation. I saw heavy equipment moving dirt and crews preparing concrete and steel.

I also saw a company doing genuinely innovative work with precast concrete techniques that could materially improve how we construct reactors in the future. None of it looked theoretical. It looked industrial.

Further west, in Kemmerer Wyo., TerraPower officially has begun construction on its Natrium power plant after receiving the first Nuclear Regulatory Commission construction permit for a commercial Gen IV advanced reactor in the United States. That milestone alone would have seemed improbable a decade ago.

Meanwhile, over at Idaho National Laboratory, Aalo Atomics recently completed construction of its Critical Test Reactor Building-part of the Department of Energy's Reactor Pilot Program-and as I write this, the company is finalizing assembly of its test reactor, with the goal of achieving criticality by July 4.

Each of these projects differs in scale, technology, regulatory pathway, and business model. But together, they represent something much larger than any individual reactor design.

They represent a new phase of the nuclear resurgence.

For years, the conversation around advanced nuclear has centered on designs, simulations, licensing pathways, and PowerPoint presentations. Those things mattered enormously-and they still do. But now, the conversation increasingly includes rebar, concrete pours, fabrication schedules, and construction sequencing. It includes supply chains, weld inspections, and shift work. It includes people in hard hats.

This transition also matters. An old colleague of mine liked to say that when you are climbing a mountain, you should turn around every so often to enjoy the view. The progress made by the nuclear community over the last decade is undeniable. The industry has moved from a period defined largely by aspiration to one increasingly defined by execution.

Of course, major questions remain. When will the next gigawatt-scale light water reactor be announced? How quickly will the industry move from microreactor prototypes to commercially manufactured fleets? Can we build quickly enough to meet the enormous electricity demand emerging from AI and industrial growth? How will the nuclear fuel industry keep pace with demand?

These are important questions for which the answers aren't necessarily clear today. But in the meantime, it is worth pausing to appreciate this moment, this transition from aspiration to perspiration, from promising innovations existing only on a hard drive or in the cloud to real steel, real concrete, and real projects rising from the ground. We've come a long way.