Since the NRC has the sole responsibility for regulating nuclear safety, the legislature of the state of Vermont had to judge Vermont Yankee on some other grounds. They chose "reliability." Is the plant reliable? States are generally able to license or not-license power plants on the basis of their cost and reliability.
Since Vermont Yankee has one of the highest capacity factors among its sister plants nationwide, and was doing a 530 day breaker-to-breaker run at the time, the legislature was kind of in a quandary. How to shut down a reliable plant on the basis of reliability?
Wink-wink, nod-nod. I have sat in many hearings where the legislators talk in fearful terms about tritium leaks, soil near a leak containing strontium (which will attack the bones of our children), a cooling tower collapse. None of these incidents caused the plant to go off-line. None of these were reliability issues.
The legislators would then turn to the audience and said: "Of course, we can't use the s-word (safety)." After a smile and a nod to the audience (they actually didn't wink), the legislators would go right back to why the plant had to be shut down for the safety of Vermont residents.
All the issues they were talking about did not affect the reliability of the plant, and the NRC assessed them as posing no danger to the public (safety). Note: The strontium-contaminated soil near the leak was taken to a radiological waste disposal site. It was about two pick-up truck loads worth of soil, according to plant spokesmen at the time.
The Pre-Emption Issue
The issue of Vermont's pre-emption of the NRC obligation to regulate plant and regulatory safety is a major contention of the Entergy lawsuit. I wrote a blog post about State's Rights and the NRC: it was posted at the ANS Nuclear Cafe site today. The ANS site gets high volumes of traffic, compared to my own blog. Please visit!