TerraPower, the nuclear technology company founded by Bill Gates, has marked with a ceremony the start of construction for its demonstration Natrium advanced nuclear plant complex near a retiring coal plant at Kemmerer, Wyoming.

A spokesperson for TerraPower told NucNet that the inaugural dig, attended by Gates, who is also company chairman, chief executive Chris Levesque and Wyoming governor Mark Gordon, was for the non-nuclear part of the plant, the first part of which will be a sodium test and fill facility.