![Leslie Dewan](https://ideas.time.com/wp-content/uploads/sites/5/2013/12/time-30-under-30-19.jpg?w=260)
Age: 28
About: Transatomic Power
Leslie Dewan’s planned Waste-Annihilating Molten-Salt Reactor,—yes, it reuses waste for fuel—could have a major impact on the energy sector. The innovative design, which she developed with a fellow MIT graduate, mixes nuclear material with molten salt to contain reactions and reduce both waste and the risk of a meltdown.