Can a nuclear explosion be peaceful? US scientists used to think so.

Fifty-five years ago this month, Milo Nordyke was staring out at the Nevada desert, waiting for a huge explosion to blow a hole in the surface of the earth.

The blast was known as Sedan, and it was one of two dozen nuclear explosions that American scientists set off for non-military purposes. It was 1962, a year when most people feared the destructive power of nuclear bombs.

But Nordyke and his colleagues believed that bombs had the power not only to destroy, but also to create. Let’s say you wanted to build a harbor or pit mine. One nuclear bomb could do the work of hundreds of bulldozers — or millions of sticks of dynamite.

“We were talking about major projects, like a Panama Canal,” Nordyke said. “So we said, ‘Let’s do a 100-kiloton explosion.’” That’s six times the explosive power unleashed in 1945 on Hiroshima, Japan.

Nordyke, who’s now 87, was studying the effects of “peaceful nuclear explosions,” or PNEs, as a physicist at California's Livermore National Laboratory. The project was called “Operation Plowshare,” in reference to an Old Testament passage about turning the weapons of war into the tools of farming.

He remembers staring out at the desert, waiting for the huge blast.

“You saw a tremendous light, a bright light,” he said. “Then you hear the sound wave that’s generated. Boom, boom!”

According to an informational video produced by the Department of Energy, the Sedan explosion created a cloud of dust that rose 12,000 feet into the air. It resulted in the largest man-made crater in America. Apollo astronauts used it to train for moon missions.

Nordyke was proud to be working on such an unusual project. “The only other persons that were doing that were the Russians,” he said. He remembers learning about Soviet tests from satellite photographs. Lake Chagan in modern-day Kazakhstan was created by a peaceful nuclear explosion.

But this was an arms race that neither country won. In the decade after Moscow and Washington banned most types of nuclear testing, in 1963, the public questioned whether nuclear tests were safe. There was even a bizarre film made about a mutant scientist at the Nevada Test Site: “The Beast of Yucca Flats.”

Audra Wolfe, a historian of the Cold War, said the dream of “peaceful nuclear explosions” had a lot to do with wishful thinking.

“If you’re a scientist or engineer who’s dedicated your life to building atomic or nuclear weapons, and you’re looking for some meaning in your life, then it can be really compelling to think that these weapons can be used for good,” Wolfe said.

She added that humans have a bad habit of expecting technology to solve all of our problems. In the end, Operation Plowshare left a legacy of radioactive fallout and waste.

“The people who were planning Plowshare were choosing to ignore those negative consequences,” Wolfe said.

In the 1970s, after 10 years and tens of millions of dollars of spending, Operation Plowshare finally went to seed.

The anti-nuclear movement that helped stop it still hasn’t quit. This week, the United Nations approved a ban on nuclear weapons, which nuclear-armed powers ignored but could become international law.

As for Milo Nordyke, he ended up learning Russian — which he used to help negotiate treaties that further restricted the use of nuclear bombs.