Doppler radar is a powerful tool for scientists to spot the formation and path of tornadoes.
We don't know what it will cost to build the next nuclear power plant in the U.S.
Greenhouse gas emissions from nuclear power are low by just about any measure.
Radioactive waste is an unavoidable by-product of nuclear power that requires safe storage.
Nuclear power results from radiation, which was discovered around 1900. It took several decades after that for scientists to understand how to harness its energy - for power and for weapons.
Over 400 nuclear reactors are operating today in the world in 30 different countries.
Nuclear power emits much lower greenhouse gas emissions than electricity from coal but there is risk of a reactor accident, unresolved issues with radioactive waste disposal, and weapons.