One problem with nuclear energy is waste storage. This adds to the cost of nuclear energy because it must first be transported and then buried in an area that is geologically "safe". Another cost is when power plants actually are decommissioned and decontaminated, once they have passed the age that they can still operate. All of the radioactive materials must be entombed or stored and the costs are staggering. Another cost is actually mining the uranium in the first place. It is quite expensive. As for social costs, the Chernobyl nuclear disaster in the Ukraine is an example of what can occur with nuclear energy gone wrong. The forests and land all around the area will remain uninhabitable for decades to come. Many people living in the area have developed cancers and other illnesses as a result of exposure to radiation during the meltdown.