Oklo, the publicly traded small-modular-reactor startup backed by OpenAI chief Sam Altman, has split its first atoms in a test reactor, Canary Media reports. The event marks an early technical milestone for one of the most visible companies working on next-generation nuclear energy.

The company has built a reputation as a retail investor favorite since its stock market debut two years ago. This test-reactor achievement adds a concrete data point to its high-profile status, though it remains one step among many in commercializing advanced nuclear technology.

This account draws on a single source, so there are no differing reports to compare. The Canary Media article frames the atom-splitting event as significant but does not indicate that Oklo has completed a full commercial reactor or produced power for the grid.