The mushroom cloud from the De Baca balloon-burst test in October 1958, just before a 3-year moratorium began (all Test Site blasts went underground after July 1962).
Chuck Costa, who witnessed the Sedan blast as a Public Health Service worker, went on to a long career assessing nuclear radiation.
Photo by Andrew James
At 10 a.m. on July 6, 1962, scientists detonated a nuclear bomb at the bottom of a 635-foot-deep, 36-inch-wide borehole in the northeast corner of the desolate stretch of desert then called the Nevada Test Site. Slow-motion footage of the blast shows a spike of steam shooting into the sky, followed by an earthen bubble rising from the desert floor as if cameras happened to be rolling when the earth was coughing up a mountain.
Three seconds after the blast, as the bubble reached 290 feet tall, streaks of fire shot into the sky, shattering the round, smooth dome and smothering the view with a roiling cloud of dust, ash and rock. Cameras positioned farther back recorded the bomb heaving 12 million tons of debris into the air, and the formation of a 16,000-foot-tall cloud of dust that drifted slowly to the northeast.
As with all 928 announced nuclear tests at the Nevada Test Site between 1951 and 1992, the shot was given an innocuous name free of religious and political connotations. Bomb builders named their creations after California ghost towns, counties in New Mexico, types of boats, the phonetic alphabet. They called this one “Sedan.”
In the vaguely agricultural vernacular of nuclear testing, Sedan’s “yield” was 104 kilotons, meaning it had the explosive power of 104,000 tons of TNT. In seconds it gouged a hole as deep as a football field is long and as wide as the Stratosphere Tower is tall, the largest nuclear crater in North America. It produced a cloud of radioactive dust that drifted across the Midwest and all the way to the Eastern seaboard within a week at a time when testing had gone underground to minimize pollution and quell public fears. And it was the second test in the Atomic Energy Commission’s ill-fated Operation Plowshare program, a government initiative to remake the world through the peaceful use of nuclear bombs. Under Plowshare, the federal government dreamed of widening the Panama Canal, blasting out a harbor in Alaska, connecting rivers in Mississippi, hollowing out vast underground storage cavities for drinking water and grinding through mountains to build roads.
It sounds like insane science fiction now, but 50 years ago Plowshare held enough promise that a group of Las Vegas businessmen formed the world’s first—and perhaps only—private company in the business of exploring for oil and gas by detonating nuclear bombs. The technology was relatively simple and devastatingly effective. Millions of tons of earth could be moved in a second thanks to the power of the atom. Bombs were the future.
Troy Wade watched the Sedan shot from the Monastery, a Test Site communications shack in the mountains high above Yucca Flat. In 1962, Wade was a young engineer working for the Lawrence Radiation Laboratory in Livermore, Calif., and assembling atomic weapons was his job. He built the Sedan bomb.
“I was 20 miles away [when it went off], but you could see the ground move up and this bubble of earth coming up, holding its shape until all the sudden the fire breaks out,” he recalls.
Construction details are classified to this day, but in layman’s terms the Sedan bomb was a simple device employing proven technology. “It was a combination of high explosives and plutonium, assembled in a way so that when the high explosives lit, the plutonium was compressed and you got a critical mass,” Wade says. “It was a couple feet in diameter and maybe 5 feet long.”
Because it was designed to demonstrate just how efficacious nuclear bombs could be in civil engineering, the Sedan device was as radioactively “clean” as possible. It yielded 70 percent fusion energy, which is low in radioactivity, and 30 percent fission. It took Wade and his crew less than a week to build, working under high security in a lightning-resistant building with parts that shipped in from all over the United States. When it came time to install the heart of the bomb, the plutonium, the crew was down to three or four people.
“It didn’t take a lot,” he recalls.
Only later, as he moved up the ranks at the Nevada Test Site did Wade, now 78 and still in Las Vegas, fully understand his old job. “It wasn’t until many years later as I moved out of hands-on stuff and moved over to the Atomic Energy Commission and became the senior test manager—the guy who figuratively has his finger on the button—that I thought, ‘My God, I used to put those things together.’”
The government may have been squeamish about invoking the almighty when it came to naming individual bombs, but it had no such reservations about the program that would use them to reshape the world.
The name “Plowshare” comes from Isaiah 2:4: “… and they shall beat their swords into plowshares, and their spears into pruning hooks: Nation shall not lift up sword against nation, neither shall they learn war any more.” The program’s philosophical outlook, if it had one, can be credited to atomic pioneer and chemist Frederick Soddy, who in 1908, decades before the atom was first split, spoke of radioactivity as a force that could “transform a desert continent, thaw the frozen poles and make the whole world one smiling Garden of Eden.”
Plowshare unofficially began in February 1957, with a secret meeting of scientists from the three laboratories—Lawrence Radiation Laboratory, Los Alamos and Sandia National Laboratory—working feverishly to stay ahead of the Soviets in the arms race. It was the brainchild of Edward Teller, the charismatic head of Lawrence Livermore who is said to be the inspiration for Dr. Strangelove in the 1964 movie of the same name. Teller, a Hungarian immigrant who worked on the Manhattan Project, was a lifelong nuclear hawk who never missed an opportunity to pitch nuclear energy, rail against test bans and advocate for huge stockpiles of nuclear weapons. For Teller, Plowshare was an extension of an unwavering belief in the power of the atom.
The 1950s were a time of frenetic testing, with bombs dropped from planes, detonated on towers or, in the case of the test shot Grable in 1953, fired from a cannon. Plowshare officially began in June 1958 with an announcement from the Atomic Energy Commission. Earlier that year, the Soviets had called for a testing moratorium; in August the U.S. responded with its own call for one, and by October both sides of the Cold War divide had halted testing. The fragile moratorium held while the United States, Great Britain and the Soviet Union tried to negotiate a permanent treaty, but was strained in May 1960 when the Soviets shot down an American U-2 spy plane over their airspace, and ultimately fractured when the Soviets resumed testing in September 1961. The United States began underground nuclear testing two weeks later.
During the moratorium, Plowshare scientists had spent their time devising elaborate civil-engineering plans using nuclear bombs, including building a second canal in Central America should the first one fall into the hands of the communists, and creating a new seaport in Alaska. When the moratorium ended, Plowshare scientists were on the button three months later with a test called Gnome, a 3-kiloton bomb set off in an underground salt dome near Carlsbad, N.M., designed to produce new isotopes and gauge how much heat a nuclear bomb generates.
Nuclear testing went underground for good in 1963 when the Soviet Union, Great Britain and the United States agreed to the Limited Test Ban Treaty prohibiting bombs in the sea, air and space.
Peggy Hallerberg watched Sedan from a trailer at the control point just below the Monastery. In 1962, Hallerberg was a 21-year-old secretary for the man who ran the Test Site’s radiation-safety department. The connection was good enough to get her a front-row seat.
“He was always a member of the test panel, and every time there was a shot he’d go out to the control point,” Hallerberg recalled in an interview for UNLV’s Nevada Test Site Oral History Project. “We were young secretaries and we would sort of pester him and say, ‘We would like to go to a shot.’ … He’d sort of just brush us off and so forth. And then one day we all came to work and he said, ‘Tomorrow we’ll all go to see a shot. We have a little shot tomorrow.’ We said, ‘Oh good.’ So we went out to the control point and that shot was Sedan, which was a phenomenal shot to see. … And the power that is so evident is pretty overwhelming.”
For Hal Aronson, a man who would later become Hallerberg’s boss, the power was transformative. Aronson, now 82 and living in San Diego, saw bombs like Sedan as more than a means to make big holes in the ground. “For oil and gas stimulation, it was a great idea,” he says. “And it still is.”
Substitute “hydraulic fluid” for “nuclear bombs,” and the idea could be ripped out of recent headlines: drill into rock formations in which oil and gas are trapped, lower a fairly small nuclear bomb to the bottom of it and light the fuse. The explosion would fracture, or “frack,” the rock, freeing the trapped oil or gas for recovery. Hydraulic fracturing was first used commercially in 1949, and is the method that has unlocked vast natural gas fields in the Upper Midwest. But nuclear bombs were once considered a better way.
In 1962, Aronson was an engineer for one of the primary contractors at the Test Site. Two years later, with partners also drawn from the ranks of Test Site contractors, he formed CER Geonuclear Corp. The firm’s offices were on Flamingo Road just east of Las Vegas Boulevard.
Aronson hired Hallerberg away from the Test Site with the promise of an exciting career in a burgeoning field. “He was just an incredible salesman,” says Hallerberg, now 71. “Hal could make you believe in anything.” She rose to the position of vice president before leaving the company in 1992, long after it dropped the “Geonuclear” from its name.
Nuclear bombs would be “a standard accepted practice within a few years,” according to a paper Aronson co-authored with other CER executives in 1967. “The broken-up rock resulting from the explosion becomes the new well bore, with a production rate of six to 12 times that of a normally completed well. … The only major foreseeable problem is the seismic shock wave.”
CER put its business plan to the test in the Grand Valley and Rifle, Colo., farming and mining areas close to Grand Junction. The first experiment was dubbed Rulison, and it took place in 1969. The second was called Rio Blanco in 1973, a series of three nuclear explosions in the same hole.
The shots were a success, of sorts. They unlocked millions of cubic feet of natural gas. Unfortunately, it was too radioactive to be sold commercially. And the blasts drew protesters, college kids and “little old ladies in tennis shoes” recalls Aronson, who thought using nuclear bombs to recover natural gas was almost as bad an idea as the Vietnam War. “When Plowshare got wiped out by the emotions of the protesters and the public, the only thing left was to look into other ways to find oil and gas,” he says. “All those hippies out there. You had a lot of that ingrained in that whole area.”
Chuck Costa was on the side of Highway 25, now state Route 375, near what would eventually become the not-exactly-burgeoning town of Rachel when Sedan was fired. Costa, now 73, was fresh out of the University of Massachusetts and six months into his job monitoring air quality in and around the Test Site with the U.S. Public Health Service. He was trained as a civil engineer and knew little about nuclear science when he arrived in Nevada. “Radiation was the least of my desires,” he said in an interview for the UNLV oral history project. “In fact, I don’t know that I even knew how to spell the word ‘radioactivity’ in those days.”
On routine days, Costa monitored a far-flung network of environmental sampling stations, driving his government-issued truck around the state. For the ranchers living in the remote valleys of Southern Nevada, he was the face of the federal government, and considered it part of his job to know them and keep them informed about what was happening at the Test Site. He had relations to mend. The era of atmospheric testing left a legacy of ill will between the government and people living adjacent to the Test Site; ranchers in Southern Nevada claimed their livestock were poisoned and burned by fallout from the Upshot-Knothole tests in 1953, and that the government refused to compensate them. Many felt they weren’t told the truth about possible health effects, and that they were being sacrificed for the sake of the Cold War. “Unlike some of the folks who preceded us [who worked at the Atomic Energy Commission],” Costa said in a recent interview, “the Public Health Service believed in interacting with people on a routine basis. We’d tell them when testing was scheduled and ask where they’d be and what they’d be doing.”
For shot days, Costa would station himself downwind to monitor fallout. On July 6, 1962, he was right in the path of the 16,000-foot cloud of radioactive dust that rose above the newly created Sedan Crater and drifted to the northeast. It smothered Highway 25 as it passed overhead, cutting visibility to nearly zero and forcing police to close the road. “All I could see from the highway was the top of the debris cloud as it came up and over the area,” he recalls. It was like a dust storm in that alluvium.”
The cloud was radioactive, he says, but the levels were low. He advised residents of a nearby ranch to stay indoors until the dust passed, he monitored the air quality from outside without protective clothing or a respirator.
For an underground test—albeit a shallow one—Sedan made quite a mess. It released high levels of iodine-131 fallout along a path east of the Nevada Test Site, reaching all the way to the Atlantic Ocean eight days after the blast. Iodine-131 enters humans through milk produced by cows that have eaten contaminated grass, and it’s linked to thyroid cancer.
A study by the National Cancer Institute found evidence of iodine-131 traceable to the Nevada Test Site almost everywhere in the country, with the highest doses in the Southwest, particularly in areas “downwind” of the Test Site. In the late 1960s, research by a doctor with the U.S. Public Health Service showed an increase in leukemia deaths in southern Utah. The Public Health Service recommended more studies, but the Atomic Energy Commission quashed the idea, fearing bad publicity and lawsuits. “Downwinders,” as they came to be known, were vindicated in a 1984 ruling in federal district court that found the federal government negligent in the way it conducted atmospheric testing: It had failed to adequately warn people nearby of the dangers, and, in the race to build bigger and better bombs, it hadn’t taken people’s safety into account. Atmospheric testing in particular, the judge ruled, had a “contributory” role in causing 10 cases of cancer in St. George, Utah—nine of them fatal—and he awarded $2.6 million in compensation to families of the victims. The ruling was overturned on appeal, but in 1990 Congress passed the Radiation Exposure Compensation Act for people who lived downwind of the Test Site and had gotten sick because of it.
After almost two decades and 27 tests, Plowshare succeeded only in proving that it is cheaper to dig holes the old-fashioned way, unless you want very big holes. (In 1965, the Soviets created Lake Chagan in Kazakhstan with a bomb modeled on the Sedan shot. The lake is almost identical in size to the Sedan Crater.) True, nuclear bombs would have been efficacious fracking tools for unlocking reserves of oil and natural gas—Las Vegas’ CER was on to something—but by the 1970s the downside of the atomic genie was well understood, the environmental movement was growing and the public had little appetite for the peaceful application of such a potentially deadly technology. The last Plowshare shot was the 1973 Rio Blanco gas-stimulation nuclear test in Colorado under the auspices of CER. In 1975, Congress defunded Plowshare.
Today the Sedan Crater is a relic; a desolate-yet-popular tourist attraction tucked away in the northeast corner of the Nevada National Security Site. The Department of Energy runs a busload of visitors monthly from its state headquarters in North Las Vegas to the crater, and the free tour is usually booked far in advance.
Removed from the frenzy of the Cold War and the unquestioning optimism of Plowshare, Sedan is just a big hole. In comparison with the vast sweep of the empty desert and the surrounding volcanic mountains, it isn’t particularly impressive. Its smooth, sandy sides slope too evenly to invoke a sense of majesty, its shape is too symmetrical to mimic the hand of nature. It’s not even particularly dangerous any longer. If you pitched a tent on the crater rim and stayed for a year, you’d receive a 130-millirem dose of radiation. The average person gets 300 millirems annually by walking in the sunshine occasionally, being near rocks or flying in airplanes.
Only in historical context does the importance of Sedan snap into focus. The crater is a reverse time capsule in which the hubris of the past isn’t buried, but fully exposed. It is the physical manifestation of a belief that if we can reshape the earth, we should. It is a portal to a modernist past when it seemed that all we needed to “make the whole world a smiling Garden of Eden” was faith in technology, trust in authority and the unwavering conviction that the power of the atom could be safely harnessed.
It’s still an enticing dream, but one tempered with the reality of Three Mile Island, Chernobyl and Fukushima. From that perspective, the Sedan Crater is among the most important places in the world.