From the Union of Concerned Scientists:
History has shown—most recently with the Fukushima disaster in Japan—that accidents happen. But those responsible for U.S. nuclear power safety and security—Congress, the White House, the Nuclear Regulatory Commission, and the nuclear industry—continue to offer overly optimistic assurances that everything is fine and everyone is safe.
In fact, they could and should be doing much more to protect Americans from a nuclear accident, and their failure to address known threats is a recipe for disaster. For example:
Radioactive fuel rods are stored in hazardous conditions at all 104 U.S. nuclear reactors
More than 40 of the 104 reactors fail to meet basic fire safety standards that have been in place for years
A dozen plants have not even fully implemented terrorism prevention requirements—10 years after 9/11
Nuclear reactors currently supply nearly 20 percent of America's electricity needs, and that won't change anytime soon. What has to change is the attitude of the people entrusted with keeping Americans safe.