This Knoxville News Sentinel / AP story suggests candidate Dean was soft on nuclear plant safety while Governor of Vermont. Read it here, and here's a taste:

Presidential hopeful Howard Dean, who accuses President Bush of being weak on homeland security, was warned repeatedly as Vermont governor about security lapses at his state's nuclear power plant and was told that the state was ill-prepared for a disaster at its most attractive terrorist target.

The warnings, according to documents obtained by The Associated Press, began in 1991 when a group of students was brought into a secure area of the Vermont Yankee nuclear plant without proper screening. On at least two occasions, a gun or mock terrorists passed undetected into the plant during security tests.

During Dean's final year in office in 2002, an audit concluded that despite a decade of repeated warnings of poor safety at Vermont Yankee, Dean's administration was poorly prepared for a nuclear disaster ...

... Environmental groups sent Dean repeated letters about the plant's security and safety. During a 1998 federal security test, mock terrorists sneaked a fake gun past security and six times scaled, undetected, the plant's security perimeter fence.

The 1998 test was alarming because seven years earlier, protesters had managed to breach the same security by scaling the fence or rafting down an adjacent river. The 2001 security test again penetrated Vermont Yankee's security.