Underground Nuclear Tests
One of the most pervasive—and erroneous—beliefs about the U.S. nuclear testing program is that its radioactive
fallout ended when the Limited Test Ban treaty took effect in 1963. When the nuclear tests went underground,
people assumed the weapons-testing radiation threat disappeared. This comforting notion, carefully nurtured by the
government, is false.
In 1979 the U.S. Government admitted that more than 35 of approximately 330 "underground" nuclear blasts sent
radioactivity outside the boundaries of the Nevada Test Site, during the 1960s and early 1970s.70 And the DOE’s test
site manager, General Mahlon Gates, said that the government still was not sure it had made public all the atomic
tests that occurred in Nevada.71 Prior to that announcement governmental spokespeople were admitting to only half
as many underground test mishaps venting radioactivity off-site. "During 18 weapons tests which accidentally
released radioactivity during the period, 1962-1971, very, very, small releases occurred," DOE media liaison David
Miller said in December 1978.72
While understating the number of underground tests spewing radioactivity beyond site boundaries, officials were
even more determined to belittle the severity of those ventings. "We didn’t believe it was a health hazard then and
don’t believe it is today," Miller insisted.73 But that kind of assurance sounded more than a little familiar. In St.
George, Irma Thomas—who had lived through the atmospheric testing days as a middle-aged woman—told us the
underground nuclear testing continued to infuriate her. "I don’t trust all that stuff about how safe it is," she said.
"We’ve heard that before."74
Across the Arizona border, in the town of Fredonia where the leukemia epidemic killed four people including her
husband, Rose Mackelprang reacted to the underground testing with gentle anger: "I don’t think that we really
should have to have any more radiation, I think we have plenty without adding to it all the time. We have about all
that we need."75
In 1980 we visited the Nevada Test Site, touring the windswept expanse of desert, accompanied by federal
officials. Signs at heavily guarded checkpoints now say "U.S. Department of Energy." As always it is a military
operation.
Amid the ugly pockmarks of the test site, where craters give off the appearance of a moonscape from the air, the
austere yet ecologically intricate desert seemed transmuted, and profoundly violated.
For the record, Nevada Test Site representatives were resolute—speaking of preparedness, national defense, a
strong "military posture." But an old hand at nuclear testing said, after asking us to turn off our tape recorder, "No
head of state, in the world, has ever seen a nuclear bomb explosion. To me, that’s scary." He added: "I don’t think
anyone who has ever seen a nuclear explosion has ever not asked the question—My God, what have we done?"76
When the 1980s began, nuclear detonations under the Nevada desert—ranging up to 150 kilotons each—were
occurring at an average rate of once every three weeks.77 After the Reagan administration gained power in 1981, it
pledged to increase that pace.
A cone-shaped crater, measuring several hundred feet deep and a quarter-mile across, was left by the hydrogen
"device" code-named Sedan. Eighteen years after it was created by the 104-kiloton thermonuclear blast, the
crater—graced with an overlook platform and an explanatory sign—had become a monument to the destructive force
of nuclear weaponry. But when it was detonated, as an experiment in possible excavation uses of nuclear energy,
Sedan sent intense radiation all the way to the Eastern Seaboard. Probably little would have been learned about this
planned disaster had not some University of Utah graduate students and their outspoken professor been visiting a
canyon about twenty miles southeast of Salt Lake City.
On July 7, 1962, radiologist Dr. Robert C. Pendleton was with students on a field trip in Big Cottonwood Canyon.
"We were measuring levels of radioactivity in different environmental situations," Dr. Pendleton remembered. "A
cloud of radioactive material came over and all the measurements began to go nuts. I recognized that we were
getting fallout and took the students off the hill and back down in the valley."78 The fallout had multiplied normal
radiation readings a hundredfold.79
There had been no warning from the government—only "the usual announcements that atomic shots were taking
place," according to Deseret News environmental reporter Joseph Bauman.80 Although the federal government was
content to let the matter rest, Dr. Pendleton was not: "We found radioactive iodine in all of the children, milk and
vegetation that we measured in the whole northern section of the state."81
Pendleton’s determination to analyze impacts of the Sedan fallout caused the Utah Department of Health to divert
thousands of gallons of milk—laced with radioactive iodine 131, a voracious destroyer of human thyroids—that
would have been otherwise consumed by Utah residents.82 The action partially deflected health damage to Utahns
from the Sedan test fallout. But it angered the White House—which "responded by ordering the Public Health
Service to clear its radiation reports through the White House press office," The Deseret News reported seventeen
years later on the basis of newly declassified federal documents.83
As long-secret records came to light, the Salt Lake City newspaper published an interview with Dr. Pendleton
about aftermaths of ostensibly nonatmospheric nuclear testing in July 1962. Radioactive iodine, cesium, and
strontium increased "very markedly" after the Sedan blast, Pendleton recalled. "We told Governor George D. Clyde
there was a risk, but the [U.S.] Public Health Service was telling the State Division of Public Health a different
story." The federal policy of dismissing radiation alarms prevented use of precautions that could have helped guard
people from exposure. As Pendleton observed, "Public relations statements that there was no harm in the fallout
clouds were reprehensible."84
During the 1960s, as Pendleton continued warning of radiation damage from underground nuclear tests, official
hostility toward him grew. The conflict escalated in 1963 with the publication of a Science magazine article on
Utah’s summer 1962 iodine 131 levels.85 Pendleton and two colleagues pointed out that the thyroids of many
thousands of Utah people were seriously threatened by nuclear detonations in Nevada the previous summer—with
children in their first two years of life put at the greatest risk of all.
In 1964 a follow-up article in Science made clear that the country as a whole remained in jeopardy from ventings
of underground nuclear tests.86 Dr. Edward A. Martell, formerly employed by the U.S. Government to monitor
fallout, documented findings that underground nuclear blasts were responsible for significant levels of iodine 131 in
milk from the Pacific Northwest and the Midwest to the southeastern United States.
"Even underground tests which are largely contained below ground with only a limited release of radioactive
gases and vapors cannot be overlooked as sources of Iodine-131," Martell wrote. He added: "Control of Iodine-131
fallout will be more effective if we control its sources rather than the distribution and consumption of fresh dairy
products. . . . The high frequency of venting of radioactive products from previous underground tests suggests that
either there was no serious attempt to contain them, or that containment is difficult and uncertain."87
To a casual observer the scientific debate over iodine 131 from underground testing might have seemed somewhat
academic. But in a community like Pleasant Grove—located near Provo, Utah, in the fallout path of Sedan and other
tests several years earlier—the issue appeared much less abstract. During the late 1960s seven children in that town
of about five thousand people died from leukemia88—a rate more than ten times higher than the national average.89
Pendleton found himself faced with cuts in federal research funds because he was coming up with Utah radiation
readings deemed "too high."90 Some of the most ominous nuclear tests were being executed under the category of
Plowshare explosions to develop nuclear technology for functions like excavation. "Surely each person to be
showered with radioactive dust from engineering tests should be fully informed of this possible hazard, and should
be given a chance to decide whether the risk is justified," Pendleton told a Science Digest interviewer in 1967. He
went on, "While we are making such strong efforts all over the nation to clear up the air and remove pollution, we
have an agency proposing to release massive quantities of radioactive air pollution to drift down over the inhabitants
of the country without even asking a by-your-leave as to whether they may do so."91
In 1981 we asked Robert Pendleton to comment on his two-decade altercation with nuclear weapons testing
authorities. Continuing his research as director of the Radiological Health Department at the University of Utah, Dr.
Pendleton seemed weary of the struggle. He declined to discuss past cover-ups and coercion directed against him.92
70. U.S. Congress, House Committee on Interstate and Foreign Commerce, Subcommittee on Oversight and Investigations, Testimony of General Mahlon Gates,
U.S. DOE manager of the Nevada Test Site, and Richard E. Stanley, acting director of the U.S. Environmental Monitoring and Support Laboratory," Las
Vegas, Nevada, April 23, 1979, unpublished transcript.
71. Ibid.
72. Washington County News (Utah), December 14, 1978.
73. Ibid.
74. Irma Thomas, interview, February 1980.
75. Rose Mackelprang, speech to National Conference for a Comprehensive Test Ban, University of Utah, Salt Lake City, December 12, 1980.
76. DOE official, who requested anonymity, during tour of Nevada Test Site, interview, February 1980.
77. David Jackson, DOE spokesman, interview, September 1980.
78. Deseret News, May 23, 1979.
79. The Tribune (Salt Lake), May 17, 1980.
80. Deseret News, May 23, 1979.
81. Ibid.
82. The Tribune, (Salt Lake), May 17, 1980.
83. Deseret News, April 24, 1979.
84. Deseret News, January 27, 1979.
85. Robert C. Pendleton, et al., "Iodine-131 in Utah During July and August 1962," Science, August 16, 1963, pp. 640-642.
86. E. A. Martell, "Iodine-131 Fallout from Underground Tests," Science, January 10, 1964, pp. 126-129.
87. Ibid., p. 129.
88. The Tribune (Salt Lake), May 17, 1980.
89. Heath, "Subject: Leukemia."
90. Deseret News, January 27, 1979.
91. Nelson Wadsworth, "Underground A-Tests May Be Making Us Radioactive," Science Digest, September 1967, pp. 15, 17.
92. Robert Pendleton to authors, January 19, 1981.