On Tuesday, the US Department of Energy (DOE) launched an application for interested parties to apply for access to a maximum of 19 metric tonnes — a little under 42,000 pounds — of weapons-grade plutonium, which has long been a key resource undergirding the US nuclear arsenal.

One of the companies anticipated to receive shipments of the fissile isotope from the DOE is Oklo, a “nuclear startup” backed — and formerly chaired — by OpenAI CEO Sam Altman. Earlier in October, Oklo was one of four US companies chosen by the DOE to join a new pilot program meant to rush the testing and approval of experimental reactor designs.