The former chair of the U.S. Nuclear Regulatory Commission says the country’s nuclear industry should be banned, after concluding that the dangers of climate change no longer outweigh the risk of catastrophic reactor accidents.

“This tech is no longer a viable strategy for dealing with climate change, nor is it a competitive source of power,” writes Greg Jaczko in an opinion piece for the Washington Post.

Nuclear “is hazardous, expensive, and unreliable, and abandoning it wouldn’t bring on climate doom,” he adds. “The real choice now is between saving the planet and saving the dying nuclear industry,” and “I vote for the planet.”

Jaczko, who chaired the NRC from 2009 to 2012 before going on to start a wind energy company, hasn’t always felt this way. “Nuclear power was supposed to save the planet,” he recalls, and around the turn of the century, “the risks from human-caused global warming seemed to outweigh the dangers of nuclear power, which hadn’t had an accident since Chernobyl, 13 years earlier.”

But his views began to change after four years of nuclear policy work in the U.S., during which he says he “witnessed the influence of the industry on the political process”. Then on March 11, 2011, two years after President Barack Obama appointed him NRC chair, a tsunami and earthquake destroyed the four Fukushima Daiichi reactors in Japan, and after months reassuring citizens that the U.S. industry was safer, Jaczko began having his doubts.

“Before the accident, it was easier to accept the industry’s potential risks, because nuclear power plants had kept many coal and gas plants from spewing air pollutants and greenhouse gases into the air,” he writes. “Afterward, the falling cost of renewable power changed the calculus. Despite working in the industry for more than a decade, I now believe that nuclear power’s benefits are no longer enough to risk the welfare of people living near these plants. I became so convinced that, years after departing office, I’ve now made alternative energy development my new career, leaving nuclear power behind. The current and potential costs—in lives and dollars—are just too high.”

Jaczko traces the severe health, safety, and economic impacts the meltdown produced in Japan, the “obvious ramifications for the entire industry”, the new safety measures NRC staff recommended to avert similar fire, earthquake, and flooding risks in the U.S., and relentless, successful lobbying by the nuclear industry and its political allies to hobble those reforms. Ultimately, he says, the high cost of the two new reactors leading the U.S. nuclear “renaissance”—US$14 and $28 billion, and rising—took nuclear of the table as a viable carbon reduction option.

“For years, my concerns about nuclear energy’s cost and safety were always tempered by a growing fear of climate catastrophe,” he writes. And “Fukushima provided a good test of just how important nuclear power was to slowing climate change: In the months after the accident, all nuclear reactors in Japan were shuttered indefinitely, eliminating production of almost all of the country’s carbon-free electricity and about 30% of its total electricity production. Naturally, carbon emissions rose, and future emissions reduction targets were slashed.”

But things sorted out over time: Eight years after the Fukushima disaster, “fewer than 10 of Japan’s 50 reactors have resumed operations, yet the country’s carbon emissions have dropped below their levels before the accident. How? Japan has made significant gains in energy efficiency and solar power. It turns out that relying on nuclear energy is actually a bad strategy for combating climate change: One accident wiped out Japan’s carbon gains. Only a turn to renewables and conservation brought the country back on target.”