Gregory Jaczko appeared on Morning Joe to plug his new book, "Confessions of A Rogue Nuclear Regulator," and explains why he wrote the book.

"I saw how the industry was regulated and how it works," he said. "This is a technology that's hazardous. It's a technology that at any moment really could lead to the kind of catastrophic accident we saw at Fukushima. I thought people should understand that. as you said, people are talking about nuclear power as the savior to climate change. That worries me more than the risk of a nuclear power accident because I don't think it can rise to that challenge."

"Your mind, you say, was changed about nuclear power. Tell me about the evolution of that change and how it coincided with your experience as NRC commissioner," Mika said.

"I started in Washington as a physicist, so I looked at every issue based on the facts, made hypotheses and revised as I learned new facts. The biggest fact that changed my mind was this accident in Fukushima. I saw 100,000 people evacuated from their homes, many permanently evacuated. That's the kind of thing you should never see from a source that generates electricity. And moreover, we were promised and the industry pledged that these kinds of accidents were in the past, and here we had one in front of us. I began to realize this is a technology that simply was too hazardous to really be a future technology," he said.

"Walk us through what impact still is found there on the ground in Japan," Jonathan Lemire said.

"There's large areas of the plant still uninhabitable. Most evacuated and can't return to their homes. Lives have been disrupted. in a way we think more with wars than with energy generation. And you have a lot of radioactive water that's being stored at the site that people really don't know what to do with. So it will be decades before -- " he said.

"How likely could something like this happen in the United States?"

"You know, it's so hard to predict," he said. "The plants operate on this precipice of normal operation on one side and catastrophic failure on the other. What we know is accidents will happen. It's just a matter of when and where. It's hard to predict. which is why the industry often touts that everything's fine."

"So for people who are trying to find a counter to fossil fuels in the fight against global warming, having nuclear power, this was the hope, right, that nuclear power could be made safer and it could be the counter in our effort to keep global temperatures from going up," Katy Kay said. "If you weigh the risks of higher global temperatures because of fossil fuel increase usage and nuclear power, you still come down firmly in the favor of non-nuclear power?"

"Yes," Jaczko said. "Because I think that's a false choice."

"The realities are right now in the marketplace are cleaner sun, wind, geothermal. These technologies are actually in some cases cheaper than nuclear and they're getting cheaper much, much faster. I actually think the future's pretty hopeful. What we need to do is let the markets decide and get out of the way of subsidizing reactors to try and keep them around. Because the reason people are doing that is to keep the reactors around. They're not really doing it to deal with climate change. You just have to let the market decide and do things with gas to maybe make gas a little more expensive. If you do that, the things that are going to fill in is really wind, sun, and geothermal. It's not nuclear."