What are some problems associated with the use of nuclear fission to supply energy needs?

Many people are scared of nuclear power due to the few, although very significant, accidents that have taken place over the years.
and while nuclear energy operates with little pollution to the environment, it certainly isn’t without its environmental impacts.
possibly the biggest concern among nuclear energy advocates is the environmental impact of uranium as a fuel source.
spent nuclear fuel takes hundreds of years to decompose before it reaches adequate levels of safety.