How Safe Are America's Aging Nuclear Power Plants?

America's nuclear power plants are aging. The anticipated lifetime originally was about 40 years, but the Nuclear Regulatory Commission is allowing them to be re-licensed for 20 more. Now a year-long investigation by the Associated Press reports that the NRC works with the industry to weaken safety standards, or fail to enforce them, in order to keep the plants running. Accidents at nuclear plants may be extremely rare, but when they happen, they're devastating. Are regulators in the US doing all that it takes to prevent another Fukushima-type incident from happening here?