Has Kronos built a reactor yet?

No — and Kronos says so plainly. What exists today is a design, a reproducible simulation, and an open data record. The honesty about that is part of the point.

Built a reactor?

No

Exists today

Design, reproducible code, two open deposits, live sim

Next physical step

A confinement testbed (the G1 program)

Prototype target

~2030 · commercial fleet ~2036+

Kronos is a design-stage company. The 2026 publications are two papers backed by two open deposits whose code you can run yourself in the live simulation. No plasma has been lit and no reactor has been built.

The roadmap is staged and stated openly: a confinement testbed first, a breeder prototype around 2030, then — funded by the breeder and gated honestly on helium-3 supply — a commercial burner fleet in the mid-2030s. Claiming more than a design at this stage would be dishonest, so Kronos doesn't.