What are the biggest problems produced by nuclear power generation?

Uranium Mining

Extraction of fissionable uranium from ore deposits can cause serious, long-term damage to the local ecology. The main extract, Uranium-238 naturally decays into several dangerous products, including Polonium-210, Lead-210, Thorium-230, and Radium-226. When the unrefined ore is brought to the surface, the non-Uranium material is separated and stockpiled on the ground, where it emits Radon gas.

Nuclear Waste

Though about 97% of the products of the nuclear fission reaction are recycled to produce additional energy, the remaining 3% consists of highly radioactive waste that must be isolated. Plutonium in the waste is of particular concern. To date the only method to handle this waste is to seal it in radiation-absorbing containers and bury them underground and away from groundwater sources so that the radioactive does not affect the surface environment.

Reactor Operation and Safety

The reaction process in the nuclear powerplants must be closely monitored to ensure the prevention of a possible meltdown, in which the heat produced in the reactor core is not adequately contained, resulting in a explosion of radioactive material into the environment surrounding the reactor. This constant monitoring requires vigilant and competent workers to quickly recognize problems and regular inspections in order to assess the safety of the reactors.