The developer of a miniature nuclear reactor said it has successfully demonstrated prototypes of its metallic fuel — a key development for the company and for the U.S. advanced nuclear reactor community, whose years-long timelines to deployment often beget sporadic messaging wins.

Oklo Inc. fabricated fuel prototypes with the Idaho National Laboratory, with multiple prototype fuel elements reaching production specification, for anticipated use in its 1-2 megawatt-electric compact fast reactor, which is intended to generate both process heat and electricity.

The demonstration is “one of the bigger steps on the pathway for us moving towards ultimately submitting a license application and trying our first reactor on,” said Jacob DeWitte, chief executive of the Sunnyvale, Calif.-based company, in an interview ahead of the announcement. The fuel prototype demonstration “ramps well into our plans” to build a commercial unit in the early 2020s, he said.

A very small reactor, DeWitte said, aligns with Oklo’s business model and technology development side. Reactors of Oklo’s size are geared especially toward use in remote areas, such as on islands or in Alaska, that often rely on expensive and emitting diesel fuel for energy.

“I think this can scale up into those markets and even more broadly,” said Zachary Bogue, a co-founder and managing partner with DCVC who sits on Oklo’s board and whose firm invests in the company. “I would like to see this become a major contributor to not only providing industrial heat, but also providing baseload electricity.”