But nuclear’s recent history has been beset by cost overruns and delays. The fresh crop of nuclear startups were largely founded to overcome those hurdles by modularizing and mass producing reactor components. If all goes as planned, the approach could speed approvals and construction of new nuclear plants.

Elon Musk weighed in on one of the first business investment unveilings by President Donald Trump Wednesday, in a move that could suggest friction at the heart of the new administration's focus on America's leadership in the global technology race.