Oklo's Groves reactor went critical 11 months after groundbreaking.

DOE confirmed first criticality on August 5 for the Groves Isotope Test Reactor in Texas, 229 days of substantial construction, which management calls the fastest greenfield-to-criticality for a full-scale privately funded and privately sited reactor ever. First reactor under the program to go critical on private land. Q2 slides pair it with $3B liquidity and a ~50% jump in construction spend; Aurora-INL targets commercial operations in 2028. Chairman Sam Altman congratulated the team publicly, which tells you which industry this is actually for.