They used their connections to Secretary of Energy Chris Wright to get priority access at LANL, who provided nuclear engineering services and an existing critical facility (including building, safeguards, instrumentation, controls, rigging hardware).

LANL operated the facility to bring it to cold critical.

This is a cool milestone for sure, but bringing legacy enriched uranium critical isn't really interesting from an engineering perspective. I think they just wanted to claim to be the first VC to do a critical assembly.

I like that Valar is trying to move fast. It's true that you can't really learn much about your reactor until you have a commercially-relevant prototype, and they're trying to get to that point really fast. Respect for that. This little criticality experiment is more of a stunt though, for sure.

BTW TerraPower, a VC-backed nuclear startup, was splitting far more atoms, at high temperature and power, in the Advanced Test Reactor 5 years ago testing new fuel they designed themselves. So while it may be true that this is the first VC-backed criticality experiment, it's not the first time VC-backed companies split the atom (which is how the Valar founder announced it).

Los Alamos National Laboratory and Valar Atomics Announce Project NOVA Criticality Milestone in Nevada

https://www.valaratomics.com/docs/Project-Nova

Non-paywall coverage:

https://thebreakthrough.org/press/valar-atomics-achieves-fir...

Ps. More Tolkien company names...