Sean Duffy wants to fast-track putting a 100kw nuclear reactor on the moon, according to a directive he sent out Thursday. It would help win the "space race."

Nuclear reactors on the moon work in much the same way as reactors on Earth, according to Bhavya Lal, a former associate administrator for technology, policy and strategy at NASA. A controlled nuclear reaction in uranium fuel is used to generate heat that in turn can be used to make electricity.