A Bit of History: Uranium Milling and the Church Rock Disaster
- Uranium Milling and the Church Rock Disaster
Church Rock, New Mexico, would seem an improbable spot for a nuclear
disaster. A dusty cluster of industrial machinery set in the arid
mesas of the great Southwest, its most distinguishing feature might be
considered a large pond of murky liquid, unusual in such dry terrain.
Church Rock also hosts a series of underground uranium mine shafts, a
mill, and a scattered community of Navajo families who survive by
herding cattle, goats, and sheep.
A deep gully leads from the mine site into the Rio Puerco, which
once flowed only when fed by spring rains. Now it is wet year round,
bolstered by water pumped from the mine shafts to keep them from
flooding. That water flowing from the mine is laced with radioactive
isotopes. And the pond hides a burden of contaminated waste.
The 350 families who water livestock in the Rio Puerco rely on their
small herds to eke out a meager existence. Many are members of the
Dine--Navajo--Nation, with incomes in the range of two thousand
dollars per year. During the hot days of the desert summer local
children would play in the stream as their parents tended the goats,
sheep, and cattle.
A Wall of Radioactive Water
In the early morning hours of July 16, 1979--fourteen weeks after
the accident at Three Mile Island--all of that changed. The dam at
Church Rock burst sending eleven hundred tons of radioactive mill
wastes and ninety million gallons of contaminated liquid pouring
toward Arizona. The wall of water backed up sewers and lifted manhole
covers in Gallup, twenty miles downstream, and caught people all along
the river unawares. "There were no clouds, but all of a sudden the
water came," remembered Herbert Morgan of Manuelito, New Mexico. "I
was wondering where it came from. Not for a few days were we
No one was killed in the actual flood. But along the way it left
residues of radioactive uranium, thorium, radium, and polonium, as
well as traces of metals such as cadmium, aluminum, magnesium,
manganese, molybdenum, nickel, selenium, sodium, vanadium, zinc, iron,
lead and high concentrations of sulfates. The spill degraded the
western Rio Puerco as a water source. It carried toxic metals already
detectable at least seventy miles downstream. And it raised the
specter that uranium mining in the Colorado River Basin may be
endangering Arizona's Lake Mead, and with it the drinking water of Las
Vegas, Los Angeles, and much of Arizona.
Except for the bomb tests, Church Rock was probably the biggest
single release of radioactive poisons on American soil. Ironically it
occurred thirty-four years to the day after the first atomic test
explosion at Trinity, New Mexico, not far away.
The source of the catastrophe was uranium mill wastes. Usable
uranium is extracted from the sandstone in which it is usually found
by grinding it fine and leaching it with sulfuric acid. The acid
carries off the desired isotopes. But the leftover waste
sands--"tailings"--still contain 85 percent of the ore's original
radioactivity, and 99.9 percent of its original volume. There are now
some 140 million tons of them scattered around the West. NRC
commissioner Victor Gilinsky and others consider them "the dominant
contribution to radiation exposure" of the entire nuclear fuel
cycle. The acid milling liquids--called "liquor"--also dissolve
dangerous traces of thorium 230, radium 222, lead 210, and other
isotopes. Because of their high radioactivity the tailings and liquor
both must be isolated from the environment--but nobody has yet
demonstrated a method with any long-term success.
At Church Rock several hundred million gallons of the liquor were
being held in a large pond so the liquids could evaporate off and the
solid tailings be stored. The whole complex was owned by the United
Nuclear Corporation (UNC), a Virginia-based firm with assets in the
hundreds of millions of dollars and influence in the New Mexico state
government. Its dam and pond at Church Rock were opened with the
understanding that they would operate just eighteen months; twenty-five
months later, at the time of the accident, no alternative sites
were being developed.
The UNC dam wall was an earthen structure with a clay core, twenty-five
feet high and thirty feet wide. On the morning of the accident a
twenty-foot-wide section of it gave way, wreaking havoc downstream.
In the desert, water is synonymous with life. In contaminating the
Rio Puerco, UNC had threatened the basis of existence for all of the
people who lived downstream. For the first time they confronted the
terrors of radioactivity. "Our hearts have been broken," said Bodie
McCray of Tsayotah. "We don't sleep worrying about it. I worry about
our children and their children."
Indeed the hundreds of families living near the spill now had to
live with the same kinds of uncertainties just beginning to plague the
people of central Pennsylvania. "Ever since the accident we've been
wanting the truth," said Kee Bennally, a silversmith playing a lead
role in the multimillion-dollar lawsuit against UNC. "They say it's
not dangerous and in a couple of days they say it is dangerous. It's
been really confusing, especially for the old people. They don't know
anything about this, the contamination, the radiation. . . ."
What made the Church Rock disaster especially tragic was that it
could have been avoided. Soon after the spill an angry U.S.
representative Morris Udall (D-Ariz.) told a congressional hearing
that "at least three and possibly more Federal and state regulatory
agencies had ample opportunity to conclude that such an accident was
likely to occur." Even before the dam had been licensed "the
company's own consultant predicted that the soil under this dam was
susceptible to extreme settling which was likely to cause [its]
cracking and subsequent failure."
Cracks had developed in the dam the year it opened, said Udall.
Aerial photographs revealed that liquor, which was supposed to be kept
away from the dam face, was lapping against it. State-required
seepage devices and monitoring wells had never been built or inspected
UNC's chief operating officer, J. David Hann, countered Udall by
blaming the accident on "a unique rock point, beneath the breach."
Because the dam had been built partly on bedrock and partly on softer
ground, that rock point "served as a fulcrum, resulting in transverse
cracking." The breach was "like many things you undertake," Hann told
the congressional hearing. "They have a risk, and we undertook this.
There was a circumstance that was not foreseen at the time."
But coming in the wake of Three Mile Island, and in light of
considerable evidence of impending disaster, Hann's arguments seemed
to carry little weight. In a special report the U.S. Army Corps of
Engineers charged that if the dam had been built to legal
specifications, according to approved design, "it is possible that the
failure would not have occurred." And a spokesman from the New
Mexico State Engineer's Office added that a "consensus" of engineers
who reviewed the accident agreed that "had the drain zone been
constructed according to the approved plans and specifications, and
had the tailings beach been in place as recommended by [UNC's]
engineers, it is likely that failure would not have occurred."
At the time of the disaster the dam was carrying a load of tailings
liquor at least two feet higher than allowed for in its designs. The
company had also failed to tell the state that cracking had been
observed. "There were significant warnings appearing before the dam
broke," said William Dircks, director of the NRC's Office of Nuclear
Material Safety and Safeguards. "I think that is the troubling part
Ultimately, for the company, the accident would mean a loss of some
revenue and bad publicity. For the people downstream life itself was
at stake. "Somehow," complained Frank Paul, vice-president of the
Navajo Tribal Council, "United Nuclear Corporation was permitted to
locate a tailings pond and a dam on an unstable geologic formation.
Somehow UNC was allowed to design an unsafe tailings dam not in
conformance to its own design criteria. Somehow UNC was permitted to
inadequately deal with warning cracks that had appeared over two years
prior to the date the dam failed. Somehow UNC was permitted to
continue a temporary dam for six months beyond its design life.
Somehow UNC was permitted to have a tailings dam without either an
adequate contingency plan or sufficient men and material in place to
deal with a spill. Somehow UNC was permitted to deal with the spill
by doing almost nothing."
Ironically the Church Rock dam was a "state-of-the-art" structure.
Paul Robinson, an Albuquerque-based expert on mining issues, warned
the Udall hearings that "UNC-Church Rock was the most recently built
and the most carefully engineered tailings dam in the state." Similar
dams owned by Anaconda, Kerr-McGee, UNC-Homestake Partners, and Sohio
were "disasters waiting to happen."
1. Kathie Saltzstein, "Navajos Ask $12.5 Million in UNC Suits," Gallup
Independent, August 14, 1980 (hereafter cited as "Navajos"); for a
general analysis of the relationship between Indians and uranium
development, see Joseph G. Jorgenson, et al., "Native Americans and
Energy Development" (Cambridge, Ma.: Anthropology Resources Center,
1978); for a broad range of information on the issue of uranium mining
and milling, contact the Black Hills Alliance, Box 2508, Rapid City, SD
2. Edwin K. Swanson, "Water Quality Problems in the Puerco River," paper
presented at the American Water Resources Association Symposium, Water
Quality Monitoring and Management, Tucson, Arizona, October 24, 1980.
3. Edwin K. Swanson, interview, May 1981.
4. Victor Gilinsky, "The Problem of Uranium Mill Tailings," paper
presented at the Pacific Southwest Minerals and Energy Conference,
Anaheim, California, May 2, 1978 (Washington, D.C.: NRC Office of
Public Affairs), No. S-78-3, p. 3 (hereafter cited as "Problem"). See
also, EPA, Environmental Analysis of the Uranium Fuel Cycle, Part
I--Fuel Supply, EPA-520/9-73-003-B, Washington, D.C: EPA Office of
Radiation Programs, 1973, p. 26.
5. Chris Shuey, "Calamity at Church Rock, New Mexico," Saturday Magazine,
Scottsdale Daily Progress, Part 1, February 14, 1981, p. 3 (hereafter
cited as "Calamity").
6. U.S. Congress, House Committee on Interior and Insular Affairs,
Subcommittee on Energy and the Environment, Mill Tailings Dam Break at
Church Rock, New Mexico, 96th Congress, October 22, 1979, pp. 1-4
(hereafter cited as Church Rock Hearings).
8. Ibid., p. 120.
9. Ibid., p. 3.
10. Ibid., p. 42.
11. Ibid., p. 39.
12. Ibid., p. 8.
13. Ibid., pp. 225-232.
Harvey Wasserman and Norman Soloman. "Uranium Mining and the Church Rock Disaster." in Killing Our Own: The Disaster of America's Experience with Atomic Radiation.
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