Spring hasn’t been a particularly kind season for the nuclear industry.

Take 1977. That April 30th, 1,800 protesters occupied the construction site for the Seabrook, N.H., power plant. More than 1,400 of them were arrested, and one of the plant’s two reactors eventually was built. But the protests focused public anxiety on costs — not just safety — which, in turn, undermined government support for Seabrook’s financing.

Seabrook’s main owner, the Public Service Company of New Hampshire, filed for bankruptcy. The plant itself, which finally went online in 1990, became the second-to-last nuclear reactor to be completed in the United States.

Or take the spring of 1979. That's when a reactor core at the Three Mile Island nuclear plant in Pennsylvania suffered a partial meltdown. Nuclear proponents point out that nobody died at Three Mile Island, and emissions exposed nearby residents to less than a single X-ray’s dose of radiation. But Three Mile Island’s Reactor 2 came perilously close to a far larger disaster.

Then came the spring of 1986. A steam explosion blew the top off a horribly designed reactor in the Ukraine called Chernobyl. Fewer than 100 people were killed by the disaster, but the World Health Organization estimates that it caused 4,000 additional cancer deaths over two decades. More than 300,000 people had to be permanently resettled. To this day, the land surrounding the plant remains off-limits because of radiation.

This has not been that kind of spring for the American nuclear industry. In fact, for the folks who split atoms for a living, things have been going quite swimmingly since last fall. Talk of a nuclear resurgence in the United States is shifting into action.

In February, President Obama announced that the Department of Energy would make $8.3 billion in loan guarantees available to the Southern Co., an electric utility that wants to add two reactors to its existing nuclear Plant Vogtle. By last week the New York Times was running photos of bulldozers clearing land at the Vogtle site in Georgia.

That’s likely to be the leading edge of a lot of nuclear action. Specialized parts manufacturers are brushing off the cobwebs along their supply lines. Regulators are suddenly hearing the dings of their desk bells, slapped by utilities that suddenly want permits.

One factor that’s driving the excitement is President Obama’s push for an additional $55 billion in loan guarantees for nuclear plants. While loan guarantees aren’t the same as handing the industry money, they do have the effect of lowering borrowing costs. And when interest expenses start getting close to a billion dollars, well, pretty soon you’re talking about real money.

Somewhere deep in the heart of the Nuclear Energy Institute, it must be gratifying to see former opponents — politicians like Sen. John Kerry and environmentalists like Greenpeace co-founder Patrick Moore — come over to the pro-nuke side.

Why are they switching? In many cases, the very same people who were worried about nuclear power in the 1970s are the ones who are most desperate to combat climate change today. And nuclear power, unlike coal or petroleum, isn’t a substantial emitter of greenhouse gases.

The most striking turnaround may be by U.S. Rep. John Hall, (D-N.Y.), who in his previous career was the lead singer and writer for the soft rock group Orleans. In the midst of his musical success, Hall was one of the protesters at Seabrook. After the Three Mile Island accident, he joined other activist singers, including Bonnie Raitt and Jackson Brown, in raising money for the cresting anti-nuclear movement.

Hall even wrote Power, the song that became the anthem of the anti-nuke movement, as this 1979 concert with Brown and others attests.

But even Hall has made his Hobson’s choice. In Congress, he’s holding his nose and voting for nuclear plant subsidies when it seems the best move to get support for solar and other renewable energy passed.

There surely are better ways to reduce carbon output — at least in the United States. A McKinsey & Co. report last year found that simple efficiency measures could cut non-transportation energy use by 23 percent while still qualifying as a cost-effective investment for businesses. Shoot — it’s hard to imagine what the solar industry couldn’t do with $55 billion in loan guarantees. Meanwhile, no matter how safe nuclear plants become, there are those nagging worries — terrorism, disposal, the problems that come along with mining uranium — that make the industry line that it qualifies as “clean energy” a bit problematic.

The sad truth is, however, that efficiency and solar power don’t have the full political muscle of the nation’s electric utilities behind them. It’s a lot more difficult for large power companies — used to selling electricity from huge, centralized production facilities — to imagine making as much money if the grid were switched over to the “small is beautiful” model of decentralized power envisioned by idealists like John Hall since the 1970s. The political reality is that efforts to fight climate change aren’t likely to gain traction in Congress without a large heap of support for nuclear power.

Backing nukes as a way to fight climate change is out of the question for many environmentalists. At times, their opposition to nuclear plants comes across more as a core belief rather than a clear-eyed evaluation of the policy options, however. Generating energy by splitting atoms is inherently evil, by that way of thinking, and there is no arguing about it.

But such beliefs don’t carry the day in policy debates. Any honest discussion over the merits and demerits of nuclear power must recognize that the calculus of risk in energy decision-making has changed. The somewhat remote and almost certainly localized risk of a nuclear plant disaster must be weighed against the global risks posed by climate change, which are more ambiguous than those posed by nuclear power.

Environmentalists undermine their own standing to the extent that they don’t come to terms with that.

Journalist Ken Edelstein writes the Planet Pundit column for the Mother Nature Network. From various coffee shops in Atlanta, he publishes an environmental news site at MyGreenATL.com.