According to the Nuclear Energy Institute (NEI), nuclear energy produces more clean-air energy than any other source. It produces 62 percent of all emission-free electricity in the United States.

2. High energy efficiency:
A relatively small amount of uranium can be used to fuel a 1000 Megawatts electric plant, providing enough electricity to power a city of about half a million people.

Renewable sources, such as solar and wind, provide only enough power to meet residential or office needs. They don’t yet have the capacity of nuclear to handle large-scale power needs, especially in the manufacturing world.

When the energy demand is ever-rising with increased level of industrialization and living standard of people. Energy is crucial to a country's economy, e.g. to make cosmetics, while more private cars bought with rising purchasing power also raises the demand for energy sources. Fossil fuels are unevenly distributed, hence many countries which have insufficient fossil fuel resources will easily be controlled by other nations which are rich in oil.
Therefore, when the energy supply cannot reach its demand, nuclear power is needed to solve the current energy crisis.