An image of the earth from space in a scene from “Pandora’s Promise.” (Robert Stone)

It has got to be a weird experience, for both environmentalists and supporters of nuclear power alike, to watch “Pandora’s Promise.” Although the documentary ultimately argues in favor of nuclear power, an energy source that’s anathema to many tree huggers, it does so in a way that’s less strenuous than strenuously ambivalent. In the end, its somewhat equivocal message — that nuclear power might just be the lesser of several evils — is more convincing than you’d think.

Despite its pro-nuke slant, environmentalists are the film’s intended audience. After all, as the film points out, most pro-business Republicans are already in love with the idea of more nuclear power plants, and need no convincing.

But left-leaning supporters of green energy aren’t just the film’s target demo. They’re also its main subjects. Gwyneth Cravens, Mark Lynas, Michael Shellenberger and other respected environmental activists, authors and experts appear throughout the film, explaining why they have recently started to reconsider their former staunch opposition to nuclear power. Contrary to the received wisdom of the environmentalist movement, they argue that nuclear power might actually be safer, cleaner and greener than many other energy sources.

The film makes one especially intriguing — and counterintuitive — assertion: that nuclear power is second only to wind turbines in terms of safety. Many more people are killed, for example, by air pollution from burning coal, according to the film. Even the manufacture of solar panels, which are apparently quite toxic to make, are more lethal.

Here, of course, is the sticking point.

Physician and anti-nuclear activist Helen Caldicott also appears in the film, calling the nuclear industry a “death industry” and claiming that fatalities from the 1986 Chernobyl nuclear plant disaster were upward of 1 million people. But several others in the film, citing reports of the World Health Organization and the United Nations, put the number at only around 50 or, if you count some sick people who haven’t yet died, in the low thousands.

That’s a big discrepancy. And no one in the film, least of all Caldicott, appears able to reconcile it. The film, by Robert Stone (“Earth Days”), leaves it hanging.

There are many reasons to be scared of nuclear power, as even those who appear on camera advocating for it admit. “When it goes wrong,” says Lynas, a British journalist and climate change activist who wrote a 2012 article titled “In Defence of Nuclear Power,” “it goes really very wrong indeed.” When Lynas visits the site of the 2011 Fukushima nuclear plant meltdown, even he admits to feeling a “wobble” in his otherwise well-articulated stance in support of nuclear power. His argument, in a nutshell, is that opposition to nuclear power is tantamount to giving up in the fight against global warming.

Another argument the film makes is that radiation itself, while admittedly dangerous, is not the demon it’s been painted as. One recurring leitmotif throughout the film is a shot of a handheld radiation dosimeter showing “normal” background radiation that, in many cases, is much higher than such “contaminated” hotspots as Pripyat, the town next to the Chernobyl plant.

There are good reasons to be skeptical of nuclear power. And to its credit, the film enumerates all of them, including the fact that plutonium, a byproduct of uranium fission, could be used to create weapons. But the example of France, a country that now gets 80 percent of its power from more than 50 clean, quietly humming nuclear plants, is held up as a success story.

Anti-nuclear activists appear in the film calling nuclear power “wicked” and “evil,” but they’re not given much opportunity to rebut the arguments that “Pandora’s Promise” sets forth. That job is given to the film’s unexpected nuclear partisans, a group of card-carrying environmentalists who lay out the concerns with nuclear power and then debunk them, one by one. At times, they sound as surprised to hear their own words as you will be.


Unrated. At Landmark’s E Street Cinema. Contains brief obscenity. 87 minutes.