Bill Gates’s TerraPower will build an advanced nuclear reactor demonstration project at a retiring coal plant in Wyoming, the state’s governor announced Wednesday, a significant milestone for the budding zero-carbon technology.

“Nuclear power is clearly a part of my all-of-the-above strategy for energy in Wyoming,” Gov. Mark Gordon, a Republican, said when announcing the demonstration project. “This plant will be the first of a new generation of nuclear plants that are smaller, modular in design and are equipped with enhanced safety measures.”