ORNL: THE FIRST 50 YEARS--CHAPTER 1: WARTIME LABORATORY
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Spreading out along broad valleys cut by the Clinch River and
framed by the foothills of the Appalachian Mountains, Oak Ridge
seems an unlikely setting for events that would change the course
of history.
At the time of the Japanese attack on Pearl Harbor on December 7,
1941, century-old family farms and small crossroads communities
such as Scarborough, Wheat, Robertsville, and Elza occupied what
was about to become the Oak Ridge Reservation. Outsiders considered
the region a quaint reminder of the 19th-century frontier that time
and progress had passed by.
In truth, the area experienced enormous change during the early
20th century. On the up side, it felt the effects of Henry Ford's
automobile and shared, to some extent, the comforts afforded by
electricity; on the down side, it reeled from the aftershocks of
the Great Depression that rocked the economy and exerted additional
pressures on the region's fragile natural resources. Located just
25 miles from the Tennessee Valley Authority's (TVA's) corporate
headquarters at Knoxville and just a few miles below TVA's huge
Norris Dam on the Clinch River, the area was, in fact, a focal
point of one of the nation's boldest experiments in social and
economic engineering. The tiny Wheat community, for example, had
been selected for a TVA-inspired venture in cooperative
agriculture.
Residents of the Oak Ridge area in 1941 did not feel bypassed by
history. But even the advent of the automobile, the introduction of
electricity, the hardships of the Great Depression, and direct
participation in an unprecedented government-sponsored social
experiment did not prepare them for what was about to happen.
In early 1942, the Army Corps of Engineers designated a 59,000-acre
(146,000-hectare) swatch of land between Black Oak Ridge to the
north and the Clinch River to the south as a federal reserve to
serve as one of three sites nationwide for the development of the
atomic bomb. About 3000 residents received court orders to vacate
within weeks the homes that their families had occupied for
generations. Thousands of scientists, engineers, and workers
swarmed into Oak Ridge to build and operate three huge facilities
that would change the history of the region and the world forever.
On the reservation's western edge rose K-25, or the gaseous
diffusion plant, a warehouselike building covering more area than
any structure ever built. Completed at a cost of $500 million and
operated by 12,000 workers, the K-25 Plant separated uranium-235
from uranium-238. On its northern edge grew the workers' city named
Oak Ridge; south of the city rose the Y-12 Plant, where an
electromagnetic method was used to separate uranium-235. Built for
$427 million, the Y-12 Plant employed 22,000 workers. Near the
reservation's southwest corner, about 10 miles from Y-12, was the
third plant, X-10.
Built between February and November 1943 for $12 million and
employing only 1513 people during the war, X-10 was much smaller
than K-25 and Y-12. As a pilot plant for the larger plutonium plant
built at Hanford, Washington, X-10 used neutrons emitted in the
fission of uranium-235 to convert uranium-238 into a new element,
plutonium-239. During the war, X-10 was called Clinton
Laboratories, named after the nearby county seat of rural Anderson
County; in 1948, Clinton Laboratories became Oak Ridge National
Laboratory.
The Laboratory, which celebrates its 50th anniversary in 1993, has
evolved from a war emergency pilot plant operated under the cloak
of secrecy into one of the nation's outstanding centers for energy,
environmental, and basic scientific research and technology
development. It currently employs about 4500 people, including
many scientists recognized internationally as experts in their
fields. Laboratory endeavors range from studies of nuclear
chemistry and physics to inquiries into global warming, energy
conservation, high-temperature superconductivity, and new
materials. Its institutional roots, however, lie with the awesome
power released by the splitting of atoms.
The Laboratory's nuclear roots run deep and nourish much of its
research on improving the safety of commercial nuclear power,
identifying effective methods of managing nuclear waste, and
achieving practical fusion power. The roots are not only deep, they
are broadly international.
Supreme irony marks the Laboratory's history. The institution was
born during war and was propelled by a sense of high-stakes
competition and urgency: if Hitler's scientists had developed the
atomic bomb first, Nazi Germany might have placed the entire world
under a fascist fist. Yet, the Laboratory's present scientific
excellence could not have been achieved without the camaraderie and
sense of collective purpose that propels international science.
Created to build a weapon capable of unprecedented destruction, the
Laboratory became an institution that nurtures the ability of
people to understand and transform their universe for the better.
For this reason and more, its story should be told.
LABORATORY ROOTS
The history of Oak Ridge National Laboratory begins in three
distinctly different places: Albert Einstein's retreat on Long
Island, New York; the executive offices of the White House in
Washington, D.C.; and university laboratories throughout the nation
and overseas, especially at the University of Chicago.
At its highest level, the scientific community is international in
scope. As fascist dictators seized power in Europe during the
1930s, some of the continent's greatest scientists fled to join
colleagues in Britain and America. Among them were the German,
Albert Einstein; the Italian, Enrico Fermi; and Hungarians, Edward
Teller, Leo Szilard, John von Neumann, and Eugene Wigner.
These brilliant minds joined cooperative international efforts to
develop atomic weapons and, later, nuclear energy, significantly
influencing 20th-century history in general and the history of Oak
Ridge National Laboratory in particular. Eugene Wigner, in fact,
has been called the "patron saint" of the Laboratory.
Eugene Wigner, a pioneering chemical engineer and physicist from
Budapest, may have been the least known of the immigrant
scientists. Completing a chemical engineering degree in Berlin in
1925, Wigner took a job at a Budapest tannery where his father also
worked. Physics was his evening and weekend hobby. His friend John
von Neumann called his attention to mathematical group theory, and
Wigner soon published a series of technical papers that applied
symmetry principles to problems of quantum mechanics. After two
years at the tannery, he accepted an assistantship in theoretical
physics in Berlin at the princely salary of $32 per month.
In Berlin, Wigner established an international reputation as a
physicist, and in 1930 Princeton University hired both him and von
Neumann, each on a half-time basis. For a few years, the two
friends commuted every six months between Berlin and Princeton
until the Nazi government terminated their employment.
Wigner then went to the University of Wisconsin to work. There he
devised a fundamental formula that enabled scientists to understand
a neutron's energy variations when channeled through materials
having different absorption capabilities. At Wisconsin, he also
discovered a university life that reached beyond academic circles
to plain people who grew potatoes and milked cows, and he met
scientists who repaired their cars and made home improvements. He
later said that at Wisconsin he came to love his adopted country.
Returning to Princeton, he studied solid-state physics and
supervised the work of graduate students. His first student,
Frederick Seitz, later became president of the National Academy of
Sciences and of Rockefeller University; his second, John Bardeen,
developed the transistor and twice received the Nobel Prize for
physics.
The increasing strength of fascist governments in Europe troubled
Wigner deeply. As a youngster, he had seen Hungary's enfeebled
monarchy supplanted by brutal communist and then fascist
governments. From personal experience, he developed an implacable
enmity toward totalitarian regimes. When he learned in early 1939
that two German chemists had discovered nuclear fission in uranium,
Wigner recognized that this discovery could lead to both weapons of
mass destruction and abundant energy for mass consumption. Fearing
Nazi Germany would initiate a crash program to develop atomic
weapons, Wigner urged the United States government to support
research on nuclear fission. He found an ally in his fellow
countryman Leo Szilard, who in Hungary had attended the same
schools as Wigner before emigrating to the United States.
Studying nuclear fission with Enrico Fermi at Columbia University
in New York City, Szilard needed additional funds to continue his
experiments with uranium and graphite. Wigner gladly lent his
support to Szilard's efforts. Because other scientists were
lobbying authorities with their own weapon schemes, Wigner and
Szilard found their campaign for nuclear fission research moved so
slowly they seemed to be "swimming in syrup."
Thinking that Washington officials would be more likely to listen
to the famous Albert Einstein, an old acquaintance from Berlin,
Wigner and Szilard sought him out in July 1939. Learning he had
left Princeton to vacation on Long Island, they drove there, found
Einstein's cabin, and explained to him why the United States should
initiate fission research before German scientists developed an
atomic weapon. As Wigner later recalled:
Einstein understood it in half a minute. It was really uncanny how
he dictated a letter in German with enormous readiness. It is not
easy to formulate and phrase things at once in a printable manner.
He did. I translated that into English. Szilard and Teller went
out, and Einstein signed it. Alexander Sachs took it to Washington.
This helped greatly in initiating the uranium project.
In October 1939, President Franklin Roosevelt appointed a committee
of prominent scientists and government administrators to manage
federally funded scientific research. Wigner, Szilard, and Edward
Teller met with the committee and requested $6000 to purchase
graphite for fission experiments. They listened to an Army officer
on the committee expound at length upon his theory that civilian
and troop morale, not experimental weapons, won wars.
Szilard later recalled that "suddenly Wigner, the most polite of
us, interrupted him. He said in his high-pitched voice that it was
very interesting for him to hear this, and if this is correct,
perhaps one should take a second look at the budget of the Army,
and maybe the budget should be cut." The officer glared in silence
at Wigner, and the committee agreed to provide funds for the
experiment.
This first $6000 of federal funding for nuclear energy research
launched a vast, multibillion-dollar program that has continued
unabated under the successive management of the U.S. Army, Atomic
Energy Commission, Energy Research and Development Administration,
and Department of Energy. The program has had direct and lasting
ties to atomic research, development, and production sites across
the United States, including Oak Ridge.
The initial funds for the uranium and graphite experiments,
however, were not released until late 1940. Wigner became
increasingly exasperated as the irreplaceable months passed. After
the war, he contended that the delay, largely the result of
bureaucratic footdragging, cost many lives and billions of dollars.
American scientists, nevertheless, made vital advances in the
interim. At Columbia University, in March 1940, John Dunning and
his colleagues demonstrated that fission occurred more readily in
the isotope uranium-235 than in uranium-238, but only one of 140
uranium atoms was the 235 isotope.
Using cyclotrons at the University of California, in 1940 Edwin
McMillan and Philip Abelson discovered element 93, the first
element heavier than uranium, atomic number 92. They named thns and
energy thus were opened for future exploration: uranium-235 could
be separated from uranium-238 for weapons use, and uranium-238
could be bombarded with neutrons--in a nuclear pile or reactor--to
produce plutonium that could then be chemically extracted for
weapons production.omic weapons and energy thus were opened for
future exploration: uranium-235 could be separated from uranium-238
for weapons use, and uranium-238 could be bombarded with
neutrons--in a nuclear pile or reactor--to produce plutonium that
could then be chemically extracted for weapons production.
METALLURGICAL LABORATORY
The day after the Japanese attacked Pearl Harbor, Arthur Compton,
a Nobel laureate at the University of Chicago, contacted Eugene
Wigner to discuss the possibility of consolidating nationwide
plutonium research efforts in Chicago. At meetings in January 1942,
Compton brought together scientists experimenting with nuclear
chain reactions at Princeton and Columbia universities with those
investigating plutonium chemistry at the University of California
to outline the plutonium project's objectives. Compton's schedule
called for determining the feasibility of a nuclear chain reaction
by July 1942, achieving the first self-sustaining chain reaction by
January 1943, extracting the first plutonium from irradiated
uranium-238 by January 1944, and producing the first atomic bomb by
January 1945. In the end, all these deadlines were met except the
last, which occurred six months later than planned.
To accomplish these objectives, Compton formed a "Metallurgical
Laboratory" as cover at the University of Chicago and brought
scientists from the east and west coasts to this central location
to develop chain-reacting "piles" for plutonium production, devise
methods for extracting plutonium from the irradiated uranium, and
design a weapon. Remaining in charge of the overall project,
Compton selected Richard Doan as director of the Metallurgical
Laboratory. An Indiana native, Doan had earned a physics degree
from the University of Chicago in 1926 and had been a researcher
for Western Electric and Phillips Petroleum before the war.
Compton also placed Glenn Seaborg in charge of the research on
plutonium chemistry and assigned him the task of devising methods
to separate plutonium from irradiated uranium in quantities
sufficient for bomb production. To coordinate the theoretical and
experimental phases of research associated with a chain reaction,
Compton chose Eugene Wigner, Enrico Fermi, and Samuel Allison.
Fermi continued his experiments with ever-larger piles of uranium
and graphite, while Samuel Allison directed a cyclotron group,
including Canadian Arthur Snell, who assessed nuclear activities in
uranium and graphite piles. Wigner and Snell later joined the X-10
staff.
Eugene Wigner headed the theoretical physics group crowded into
Eckart Hall on the University of Chicago campus. His "brain trust"
of 20 scientists studied the arrangement, or lattice, of uranium
and control materials for achieving a chain reaction and planned
the design of nuclear reactors. Among Wigner's group were Gale
Young, Kay Way, and Alvin Weinberg, all of whom later moved to Oak
Ridge.
Having a chemical engineering background, Wigner also offered
advice to Glenn Seaborg and his staff of University of California
chemists, who were seeking to separate traces of plutonium from
uranium irradiated in cyclotrons. This task was particularly
challenging because to that point no one had isolated even a
visible speck of plutonium. By September 1942, the team had
obtained a few micrograms of plutonium for experimentation, but
they needed much more for additional analysis.
In 1942, Compton brought Martin Whitaker, a North Carolinian who
chaired New York University's physics department, to Chicago to
help Enrico Fermi and Walter Zinn build subcritical uranium and
graphite piles. He later put Whitaker in charge of a laboratory
under construction in the Argonne forest preserve on Chicago's
southwest side. It was here that Compton initially planned to bring
the first nuclear pile to critical mass. A strike by construction
workers, however, prevented the laboratory's timely completion. As
a result, Compton and Fermi decided to build a graphite pile housed
in a squash court under the stands of the University of Chicago's
stadium.
Leo Szilard and later Norman Hilberry were placed in charge of
supplying materials for the pile experiments. They obtained
impurity-free graphite from the National Carbon Company in
Cleveland, Ohio, and the purest uranium metal available from Frank
Spedding's research team at Ames, Iowa. George Boyd and chemists at
Chicago analyzed the materials to ensure the absence of impurities
that might interfere with a nuclear reaction, and Fermi and his
colleagues put the materials into a series of subcritical uranium
and graphite piles built in what was to become the world's most
famous squash court. Fermi called them piles because, as the name
implies, they were stacks or piles of graphite blocks with lumps of
uranium interspersed between them in specific lattice arrangements.
Uranium formed the "core," or source of neutrons, and graphite
served as a "moderator," slowing the neutrons to facilitate nuclear
fission. In truth, the piles were small, subcritical nuclear
reactors cooled by air, but the name reactor did not replace pile
until 1952. Fermi gradually built larger subcritical piles,
carefully measuring and recording neutron activity within them,
edging toward the point at which the pile would reach "critical
mass" and the reaction would be self-sustaining.
On December 2, 1942, Fermi, Whitaker, and Zinn piled tons of
graphite and uranium on the squash court to demonstrate a
controlled nuclear reaction for visiting dignitaries standing on a
balcony. Controlling the reaction with a rod coated with cadmium,
a neutron-absorbing material, Fermi directed the phased withdrawal
of the rod, carefully monitoring the increased neutron flux within
the pile. The pile went "critical," achieving self-sustaining
status at 3:20 p.m., an event later hailed as the dawerial, Fermi
directed the phased withdrawal of the rod, carefully monitoring the
increased neutron flux within the pile. The pile went "critical,"
achieving self-sustaining status at 3:20 p.m., an event later
hailed as the dawn of the Atomic Age. Having no shield to prevent
a release of radiation, Fermi briefly operated this Chicago Pile 1,
disassembled it, and in 1943 rebuilt it with concrete
radiation-protecting shielding as Chicago Pile 2 at the Argonne
laboratory.alled, "with a piece of cotton clothesline over a pulley
and two lead weights to make it `fail-safe' and return to its zero
position when released." Once the experiment succeeded and his
concern that the clothesline would slip off the pulley proved
unfounded, Fox recalled his elation: "It was as though we had
discovered fire!"
After the dignitaries departed, Wigner brought out a bottle of
Italian Chianti in honor of Fermi's achievement and shared toasts
with the workers. He had carried the bottle from Princeton and
later claimed it had taken more foresight to anticipate that the
war would make Chianti a rare wine than to predict that Fermi's
chain reaction would succeed. Among the celebrants were Richard Fox
and Ernest Wollan, who had monitored and recorded the radiation
emitted by the reaction. Both left Chicago for Oak Ridge in 1943.
Wollan conducted neutron diffraction experiments, and Fox applied
his talents in the Instrumentation and Controls Division, where he
worked for half a century.
Producing sufficient plutonium for weapons required the
construction of large reactors operating at high power levels and
releasing large amounts of heat and radiation. Metallurgical
Laboratory engineers Thomas Moore and Miles Leverett, both
recruited from the Humble Oil Company, began an intensive
investigation of potentially larger reactor designs. Scaling up
Fermi's pile would not do, because extracting plutonium from the
uranium would require tearing the pile apart each time and then
reassembling it--a risky, time-consuming exercise. Moore and
Leverett developed a new design that used helium gas under pressure
as the coolant to remove heat from the pile during a nuclear
reaction. To extract the uranium without disassembling the graphite
moderator, they designed holes or channels that extended through
the graphite to allow the insertion of uranium rods. The rods could
then be removed after they had been irradiated.
Scientists agreed that thick shells of concrete could contain the
radiation from reactors, but they disagreed about methods for
removing the heat. Fermi wanted an air-cooled reactor, with fans
forcing air through channels alongside the uranium rods. Moore and
Leverett preferred using helium gas under pressure. Szilard favored
a liquid bismuth metal coolant, similar to the system he and
Einstein had patented for refrigerators. And Wigner preferred plain
river water, with uranium rods encased in aluminum to protect them
against water corrosion. Wigner's water-cooling plan eventually was
adopted for use in large reactors, but not before the decision to
build Fermi's air-cooled graphite and uranium pilot reactor at Oak
Ridge had been made.
The proposed pilot reactor would test control and operations
procedures and provide the larger quantities of plutonium required
by the project's chemists. In mid-1942, Glenn Seaborg's group had
used a lanthanum fluoride carrier process to separate micrograms of
plutonium from uranium irradiated in cyclotrons; they now sought a
means to achieve the separation on an industrial scale. In
addition, Isadore Perlman, Charles Coryell, Milton Burton, George
Boyd, and James Franck headed teams investigating the chemical and
radiation novelties of plutonium, radiation, and fission products
created during nuclear reactions.
Among the various methods investigated for separating plutonium
were the ion-exchange and solvent-extraction processes. Although
not adopted in 1943, these studies provided foundations for the
postwar separation of radioisotopes and the widely used
solvent-extraction methods for recovering uranium and plutonium
from spent nuclear fuel. In 1943, Seaborg and Du Pont chemist
Charles Cooper settled on a small pilot plant using the lanthanum
fluoride carrier built on the Chicago campus and another pilot
plant using a bismuth phosphate carrier planned for Oak Ridge. In
both cases, the separation would have to be conducted by remote
control in "hot cells" encased in thick concrete to protect the
chemists from radiation.
TO THE HILLS
As the Metallurgical Laboratory's research continued, studies began
of potential sites for the planned industrial-scale uranium
separation plants and pilot plutonium production and separation
facilities. An isolated inland site with plenty of water and
abundant electric power was desired.
At the recommendation of the War Production Board, Compton's chief
of engineering, Thomas Moore, and two consulting engineers visited
East Tennessee in April 1942. They found a desirable site bordering
the Clinch River between the small towns of Clinton and Kingston
that was served by two railroads and Tennessee Valley Authority
electric power. Arthur Compton then inspected the site, approved
it, and visited David Lilienthal, chairman of the TVA, to describe
the unfolding plans to purchase the land.
Lilienthal was dismayed by news that land near Clinton would be
taken. He objected that the site included land selected for an
agricultural improvement program and proposed instead that Compton
choose a site in western Kentucky near Paducah.
Compton refused to consider Lilienthal's proposal and advised him
that the land in East Tennessee would be taken through court action
for immediate use. He urged Lilienthal not to question his judgment
or inquire into the reasons for the purchase. "It was a bad
precedent," Lilienthal later complained. "That particular site was
not essential; another involving far less disruption in people's
lives would have served as well, but arbitrary bureaucracy, made
doubly powerful by military secrecy, had its way."
In June 1942, President Roosevelt assigned to the Army the
management of uranium and plutonium plant construction and nuclear
weapons production. High-ranking Army officials, in turn, delegated
this duty to Colonel James Marshall, commander of the Manhattan
Engineer District headquartered initially in New York City and
later relocated to Oak Ridge. Because Fermi had not yet achieved a
self-sustaining chain reaction, Marshall and Army authorities
postponed their efforts to acquire the land. The delay disturbed
some scientists anxious not to lose ground to the Germans. It also
perturbed the hard-driving deputy chief of the U.S. Army Corps of
Engineers, Brigadier General Leslie Groves.
Given command of the Manhattan Project in September 1942, Groves
ordered the immediate purchase of the reservation, first given the
code name Kingston Demolition Range after the town south of the
reservation and later renamed Clinton Engineering Works after the
town to the north. The Army sent an affable Kentuckian, Fred
Morgan, to open a real estate office near the site and purchase the
land through court condemnation, thereby securing clear title for
its immediate use. About 1000 families on the reservation were paid
for their land and forced to relocate. Existing structures were
demolished or converted to other, war-related uses. New Bethel
Baptist Church at the X-10 site, for example, was used for storage,
meetings, and experiments.
To speed production of weapons materials, Groves selected
experienced industrial contractors to build and operate the plants.
In January 1943, he persuaded Du Pont to initiate construction of
both the pilot facilities at X-10 in Oak Ridge and the full-scale
reactors to be built later in Hanford, Washington. Involved in too
many military projects and reluctant to undertake the work at X-10,
Du Pont executives were persuaded to accept Groves' request partly
through appeals to their patriotism. The contract stipulated that
Du Pont would withdraw from the job at war's end, accept no
work-related patents, and receive no payment other than their costs
plus a $1 profit. After the war, Groves reported with amusement that
government auditors allowed Du Pont a profit of only 66› because
the company had finished its job ahead of schedule.
Groves called on the University of Chicago to operate the pilot
plutonium plant planned at X-10. Scientists at the Metallurgical
Laboratory in Chicago expressed initial dissatisfaction with this
proposal. Wigner and others had wanted to design and construct the
plants, and they were not interested in operating them after Du
Pont had been given the jobs they had sought. Also, university
scientists and administrators preferred building the pilot plant in
the Argonne forest convenient to Chicago; the prospect of operating
industrial facilities 500 miles from their campus in the remote
hills of Tennessee did not elicit much enthusiasm.
Groves and the Army again used appeals to patriotism to help
persuade the university to accept the challenge. The compromise
called for Chicago to supply the managers and scientists needed for
the operations and for Du Pont to mobilize construction and support
personnel.
X-10 CONSTRUCTION
On February 1, 1943, Du Pont started clearing the X-10 site,
installing utility systems, and building the first temporary
buildings, mostly wooden barracks. In March, construction of six
hot cells for plutonium and fission product separation began. The
cells had thick concrete walls with removable slab tops for
equipment replacement. The cell nearest the nuclear reactor housed
a tank for dissolving uranium brought from the reactor through an
underground canal; four other cells housed equipment for successive
chemical treatment of the uranium--precipitation, oxidation,
reduction; a sixth cell stored contaminated equipment removed from
the other cells. An adjoining frame structure housed the remote
operating gallery and offices.
Other structures rising at X-10 housed chemistry, physics, and
health physics laboratories; machine and instrument shops;
warehouses; and administration buildings. Because construction of
the Y-12 and K-25 plants on the reservation also began in 1943, Du
Pont had difficulty finding enough workers. It remedied the
shortage by dispatching recruiters throughout the region.
Including the smallest structures, about 150 buildings were
completed that summer by 3000 construction workers, at an initial
cost of $12 million. Construction materials included 30,000 cubic
yards of concrete, 4 million board feet of lumber, 4500 gallons of
paint, and 1716 kegs of nails. Buildings went up rapidly, but needs
so outran accommodations that a workers' cafeteria operated in a
striped circus tent and an old schoolhouse served as office space
and a dormitory.
Foundation excavations for the Graphite Reactor began in late April
1943; the reactor's 2-meter- (7-foot)-thick concrete front face was
in place by June, and the side and rear walls were constructed in
July. The National Carbon Company delivered graphite of the
required purity to X-10, where Du Pont built a fabrication shop to
machine graphite blocks to the desired dimensions. In September, a
crew stacked the first of 73 layers of graphite blocks within the
concrete shield to form a cube 7.3 meters (24 feet) on a side and
at month's end installed steel trusses to support the concrete lid
capping the reactor. Under government contract, the Aluminum
Company of America began encasing 60,000 uranium slugs in aluminum
for the reactor. Mounted in a building near the reactor, two of the
world's largest fans sucked outside air through the reactor and
then up a stack. The stack and the black building that housed the
reactor (called the "black barn") were prominent features everyone
noticed when arriving at X-10 during the war.ater-cooled reactors.
Instead, Du Pont officials viewed the hot cells of the separations
building adjacent to the X-10 reactor as a pilot plant for similar
facilities to be built at Hanford, and they considered development
of chemical separations processes the most daunting mission at
X-10.
The need for safe plutonium separation challenged chemical
engineers to design, fabricate, and test equipment for remotely
transferring and evaporating liquids, dissolving and separating
solids, and handling toxic gases. Instrumentation was needed for
remote measurements of volumes, densities, and temperatures in a
hazardous environment. Techniques to separate microscopic amounts
of radioactive elements from volumes of liquid thousands of times
larger had to be invented. The unknown effects of intense radiation
on the solvents had to be identified and handled. Disposal of
contaminated equipment and unprecedented volumes of radioactive
wastes had to be addressed. These were a few of the difficulties
facing Clinton Laboratories personnel as work progressed at X-10
during the autumn of 1943.
The organization of Clinton Laboratories was in constant flux
during the war. Scientists and technicians moved from Chicago to
Oak Ridge to Hanford and Los Alamos as if they were in a revolving
door. Many members of the original Oak Ridge research staff came
from Chicago. The Du Pont Company brought its construction and
operations personnel to Oak Ridge for training, then moved them to
Hanford. Most Du Pont personnel came to X-10 from ordnance plants
the company had constructed before 1943. Wartime employment at
Clinton Laboratories leveled off in 1944 at 1513 scientists,
technicians, and operating personnel, including 113 soldiers from
the Army's Special Engineering Detachment assigned to the Manhattan
Project.
Organization of the Laboratory proceeded in 1943, with Martin
Whitaker as its director and Richard Doan as its associate director
for research. Reporting directly to Whitaker were research manager
Doan, Simeon Cantril (and later John Wirth) of the Health Division,
and plant manager S. W. Pratt, who brought many Du Pont personnel
to Oak Ridge. When its initial organization took shape, Clinton
Laboratories had units oween in 1943, when Du Pont had completed
the final engineering of the Graphite Reactor, Whitaker brought
Compton and Fermi from Chicago to witness its first operation.
Three days later, workers began to insert thousands of uranium
slugs into the reactor. The sequence involved loading a ton or two,
withdrawing control rods to measure the increase in neutron flux,
reinserting the rods into the pile, loading another batch of
uranium, then stopping again to assess activity, each time
attempting to estimate when the reactor would achieve a
self-sustaining chain reaction. A second shift continued this
tedious procedure into the night, with Henry Newsom and George Weil
plotting the flux curve. Weil had manipulated the control rod when
Fermi brought Chicago Pile 1 to criticality the previous December,
and he had come from Chicago to help achieve the same result in Oak
Ridge.when Fermi brought Chicago Pile 1 to criticality the previous
December, and he had come from Chicago to help achieve the same
result in Oak Ridge.
The day shift loaded nearly 10 tons of slugs, and the night shift
set out to beat this record, working at both ends of the scaffold
elevator at the reactor's face under the supervision of Kent Wyatt.
In the middle of the night, Newsom and Weil, in the plotting room,
recognized that one more batch of slugs would bring the reactor to
the critical point, and they stopped the loading. Before dawn on
November 4, Louis Slotin drove to the Guest House to awaken the two
Nobel laureates, Compton and Fermi, known by the aliases Holley and
Farmer in Oak Ridge. In the dark, they raced down Bethel Valley
Road to witness the reactor going critical at 5:00 a.m. Scientists
aware that the world's first powerful nuclear reactor had gone
critical that morning were thrilled. John Gillette, a Du Pont
engineer on the graveyard shift that had loaded the last 20 tons of
uranium slugs, was "too pooped to care."
Arthur Rupp of the Engineering Division had been dubious of
Wigner's theoretical calculations of the amount of heat that
uranium would emit during fission. To test the computations, he and
his colleagues calibrated the air flow through the reactor and
installed temperature, humidity, and barometric instruments. They
then compared the uranium fission rate with the amount of heat
released. When the experimental value proved nearly the same as the
theoretical prediction, Rupp's skepticism ended. "I knew then," he
said, "the atomic bomb was going to work!"
As Wigner and Alvin Weinberg at Chicago had predicted during the
design phase, the reactor had gone critical when about half its
1248 channels were loaded. Initially called the X-10 or Clinton
Pile, it became known as the Graphite Reactor. Noted for its
reliability, it worked with few operational difficulties throughout
20 years of service. Near the end of November 1943, it discharged
the first uranium slugs for chemical separation. By year's end, the
chemists had successfully extracted 1.54 milligrams of plutonium
from the slugs and dispatched them to Chicago, by secret courier,
in a container resembling a penlight. Blocking empty channels in
the graphite (to concentrate the cooling air) allowed an increase
in the reactor's thermal power to 1800 kilowatts in early 1944.
Subsequent air-flow modification, plus the installation of larger
fans for cooling, permitted its operation at more than 4000
kilowatts, nearly four times the original design capacity, with
corresponding increases in plutonium production.
PLUTONIUM PRODUCTION
In February 1944, the first plutonium shipment went from Oak Ridge
to Los Alamos. By spring, the chemists had improved the bismuth
phosphate separation process to the point that 90% of the plutonium
in the slugs was recovered. In early 1945, when plutonium
separation ceased at X-10, the Graphite Reactor and separations
plant had produced a total of 326.4 grams of plutonium, a
substantial contribution to nuclear research and ultimately to
weapons development.
In early 1945, Robert Oppenheimer urgently asked Clinton
Laboratories to supply Los Alamos with large quantities of pure
radioactive lanthanum, called "RaLa," the decay product of
radioactive barium-140. Clinton's chemists separated the first
quantity of this isotope from the reactor's fission products in
glass equipment in the chemistry laboratory. To obtain larger
amounts safely, Martin Whitaker assigned Miles Leverett the job of
designing, constructing, and operating a barium-140 production
facility. With support from the Chemistry Division, Leverett,
Charles Coryell, and Henri Levy met the schedule and Oppenheimer's
requirements. "I believe," Leverett later speculated, "that this
was the first production of a radioisotope on a large scale."
To assist with the design of Hanford's plutonium production
reactors, many experiments were performed at the Graphite Reactor
during 1944. One test involved laminated steel and masonite
radiation shields designed for Hanford. The shield samples were set
in an opening in the Graphite Reactor to study the interactions
between the samples and radiation. Brass, neoprene, bakelite,
rubber, and ordinary construction materials to be used at Hanford
also were exposed to radiation in the Graphite Reactor to analyze
their performance. Because the Hanford reactors were to be water
cooled, tubes were installed in the Graphite Reactor to circulate
water and observe its cooling and corrosive effects.
The conventional relationship between pilot plant and production
plant existed between the Clinton Laboratories' hot cells and
similar concrete structures built at Hanford. George Boyd, John
Swartout, and other chemists from Chicago moved to Oak Ridge in
October 1943, where they continued their investigations of
plutonium separation processes and the properties of plutonium. The
Clinton experience indicated the bismuth phosphate carrier process
was not entirely suitable for the plutonium separation process, but
Seaborg's other process, using lanthanum fluoride, worked well.
This process was incorporated into Hanford's separation facilities.
So was the experience of hundreds of personnel trained at Clinton
Laboratories.
Physicist John Wheeler worried that unwanted isotopes capable of
stopping chain reactions would be found in the irradiated uranium.
Like the boron and cadmium used in reactor control rods, the
isotopes would have a large neutron-capture cross section--that is,
they might absorb enough neutrons to kill a nuclear chain reaction.
This problem occurred at the first Hanford reactor during its trial
run, a nasty surprise to Fermi and all concerned. After the chain
reaction became self-ction--that is, they might absorb enough
neutrons to kill a nuclear chain reaction. This problem occurred at
the first Hanford reactor during its trial run, a nasty surprise to
Fermi and all concerned. After the chain reaction became
self-sustaining, the reactor stalled. A few hours later, the
reactor, for unexplained reasons, started again. Fermi and Wheeler
suspected that the isotope xenon-135 was the culprit because the
time required for this short-lived isotope to decay was roughly
equal to the duration of the reactor's shutdown.les in the Graphite
Reactor, and obtain rough estimates of its ability to capture
neutrons, an ability measured in "barns" (from the folk idiom "big
as the broad side of a barn").
They measured xenon-135 at four million barns; that is, tiny
amounts of xenon could shut down large reactors, which would start
again after the xenon decayed.
Clinton Laboratories was criticized for not detecting xenon's
effects during earlier Graphite Reactor operations. A decline of
reactivity resulting from xenon poisoning had occurred in the
Graphite Reactor, but the reactor's conservative design had
overcome the poisoning effects. The reactor did not shut down, and
the staff did not notice its decline in reactivity.
Fortunately, at Hanford the DuPont engineers had designed reactors
larger than necessary. This overdesign allowed the insertion of
sufficient uranium fuel to overcome xenon's poisoning effects and
to continue production of the plutonium later used in the "Trinity"
test in July 1945 and ied reactors larger than necessary. This
overdesign allowed the insertion of sufficient uranium fuel to
overcome xenon's poisoning effects and to continue production of
the plutonium later used in the "Trinity" test in July 1945 and in
the bomb that devastated Nagasaki, Japan, on August 9. se calutrons
for the separation of stable isotopes needed for industrial and
medical purposes.
BATTLE OF THE LABORATORIES
Announcing the bombing of Hiroshima, President Harry Truman
mentioned the weapons facilities built at Oak Ridge, Hanford, and
Los Alamos, commenting: "The battle of the laboratories held
fateful risks for us as well as the battles of the air, land, and
sea, and we have now won the battle of the laboratories as we have
won the other battles."
This news came as a surprise even to some employees at Clinton
Laboratories. Before he heard the president's announcement, reactor
operator Willie Schuiten did not believe co-workers who told him
the reactor's work was tied to a new weapon. He later commented,
"The people in charge really did a good job of keeping the project
a secret."
Many Oak Ridge scientists, however, knew or surmised the purposes
of the project. News of the bomb's success elated them, especially
if they had relatives serving in the armed forces in the Pacific.
One physicist commented that "we had helped to do a bold and
difficult job, and had stopped a war in its tracks." He added,
"That was enough for the moment. Second thoughts came later."
A few days later came Japan's surrender and the end of World War
II. Staff members drifted about Clinton Laboratories, gathering and
talking, seemingly bereft of energy. "Everyone," admitted one
scientist, "felt a sense of disorientation, of slackness, of loss
of direction."
The war's end had come while Clinton Laboratories was in the throes
of a management change. In July 1945, one month before the first
atomic bomb was dropped, the University of Chicago withdrew as the
contract operator, and the Army selected Monsanto Chemical Company
as the new operator. Ton Laboratories with both a pride in their
accomplish-ment and a sense of anxiety. Their prime task of guiding
the Hanford facility in producing and separating plutonium for use
in an atomic bomb had been accomplished on schedule. But with this
task successfully completed, the future looked uncertain. Could the
research facility be as useful and productive in peace as it had
been in war? Would its scientists be content to remain in the
hills of East Tennessee, or would they opt to return to more
cosmopolitan settings in Chicago, New York, and California? Would
the federal government be willing to invest as much money in the
peaceful uses of nuclear energy as it had in weapons production?f
East Tennessee, or would they opt to return to more cosmopolitan
settings in Chicago, New York, and California? Would the federal
government be willing to invest as much money in the peaceful uses
of nuclear energy as it had in weapons production?
Although the Oak Ridge facility had shed its wartime cloak of
secrecy to emerge as a heroic place, its future was still
uncertain. Impressed by the bucolic atmosphere and substantial
record of accomplishment, Wigner thought Clinton Laboratories did
indeed have a future. In late 1944, he drew up a plan for an
expanded postwar laboratory for nuclear research with perhaps 3500
personnel and an associated school of reactor technology.
Furthermore, he hoped he and his theoretical group in Chicago would
be transferred as a unit to Oak Ridge. When that was not done, he
persuaded some of his staff in Chicago to move south, starting in
May 1945 with Alvin Weinberg. Wigner followed in 1946, marking the
opening of a volatile era in the Laboratory's history. Like the
rest of America and the world, the Laboratory, whose energies and
resources had been focused exclusively on war, would have to learn
to live with peace.
SIDEBARS
ATOMS IN APPALACHIA
Before late summer of 1942, residents of four rural communities in
the Clinch River valley farmed the land, growing tobacco and corn
and raising cattle, chickens, and pigs. Some men made cornmeal in
grist mills, and others mined coal in the nearby Cumberland
Mountains. Women canned berries, beans, pickles, and peaches in
their clapboard homes or log cabins. Families participated in hog
killings, quilting parties, strawberry picking, ice cream making,
and corn shucking. Children traded eggs and berries for candy in
the country store, where villagers gossiped and exchanged news.
Families worshiped and enjoyed all-day singings, square dancing,
pie suppers, and homecomings at their local churches.
The land occupied by these settlers had been acquired for
homesteading in 1798 by a treaty between the U.S. government and
several Cherokee tribes. Some of the residents of the four
communities had moved there after being displaced by government
activities such as the establishment of Great Smoky Mountains
National Park by the National Park Service and the construction of
Norris Dam by the Tennessee Valley Authority. In September 1942,
about 1000 families were displaced again by the U.S. government's
acquisition of 59,000 acres for the wartime Manhattan Project.
The four displaced communities were Elza, Robertsville, Wheat, and
Scarborough (now spelled Scarboro).
Elza, named after a construction engineer in charge of building a
railroad bridge there, was once the home of John Hendrix, the
"prophet" who around 1900 predicted that Bear Creek Valley (where
the Oak Ridge Y-12 Plant stands) "someday will be filled with great
buildings and factories, and they will help toward winning the
greatest war that ever will be."
Robertsville was settled in 1804 by Collins Roberts, who had
received a 4000-acre land grant in what is now Oak Ridge.
Robertsville High School was built there around 1915; its
auditorium is now the gymnasium of Robertsville Junior High School.
Wheat, settled in the middle of the 19th century, was named after
the first postmaster, Frank Wheat. It was the home of Roane
College, a liberal arts college that was open from 1886 through
1908. The community was dispersed by acquisition of the land for
the K-25 Site.
Oak Ridge National Laboratory and its surrounding land displaced
Scarborough, which was founded in the 1790s and named after three
early settlers--Jonathan, David, and James Scarborough, brothers
from Virginia. The area had been called Pellissippi by the
Cherokees.
Of the four communities that predated Oak Ridge, only Scarborough
retains much of its old character (although the houses and country
stores along Bethel Valley Road are gone). Scarborough Elementary
School burned in the late 1920s but it was rebuilt as a brick
structure, part of which is still standing and used by the Oak
Ridge Institute for Science and Education.
Also standing is the New Bethel Church across from ORNL. Church
leaders were convinced that the government would tear down the
church in 1942, so they voted to erect a monument to the church as
their last official action. The memorial behind the church reads
"Erected in Memory of New Bethel Baptist Church, Open 1851 Closed
1942...Church Building Stood 47 Feet in Front of this Stone."
However, the U.S. government let the building remain and used it
for storage, meetings, and experiments. It serves today as a museum
about the residents who had to move and leave their beloved land.
Residents of Scarborough were as unhappy as the settlers in Wheat,
Robertsville, and Elza about leaving their farms and land. But, as
one of them said: "What do you do? The government needed your land
to win the war. Who would refuse such a request as that?"
REVOLVING DOOR OF SUCCESS
Who can enter a revolving door behind you and exit it before you?
A Hungarian!
This complimentary joke referred to the band of scientifically
gifted Hungarians who came to America during the Great Depression
of the 1930s looking for freedom and opportunity. Among them,
Edward Teller is best known as the "father of the hydrogen bomb"
and an advocate of the "Star Wars" defense strategy. Leo Szilard,
remembered for his whimsical ingenuity, envisioned the nuclear
chain reaction and conceived a cyclotron; he also held a joint
patent with Albert Einstein for a refrigerator cooled by liquid
metal. John von Neumann's mathematical wizardry aided the
development of mathematical theory and early computers. Least known
of the group was Eugene Wigner, a chemical engineer and physicist
who was an instrumental figure in the Manhattan Project and in the
Laboratory's formative years.
All four scientists were from Budapest. In fact, von Neumann and
Wigner attended the same high school and were inspired by the same
teacher, Laszlo Ratz, who opened the doors to science and
mathematics for them. For the brilliant von Neumann, Ratz created
a special class of one, possibly explaining why von Neumann, as an
adult, seemed aloof. Wigner remained with the other students, but
when Ratz asked the class questions, he often told Wigner to be
quiet to give the others a chance to respond. Wigner was quiet by
nature--shy and so slight that his classmates dubbed him "Little
Gene." Impeccably dressed, usually in gray, he blended unnoticed
into crowds.
Wigner came to America with his friend von Neumann in 1930. He
played a pivotal role in the development of the atomic bomb and in
the design of nuclear reactors that produced weapon materials and
electrical power. After World War II, he became the Laboratory's
research director. His career took him back and forth from what he
described as "monastic" university life at Princeton University to
the turmoil of industrial-strength science, including many visits
and three lengthy stays at the Laboratory. He was in Oak Ridge in
1963 when news came that he had been awarded the Nobel Prize for
physics.
Like Wigner's Hungarian school-mates, his friends at Oak Ridge
learned to admire his steadfast passion for perfection in both
science and his personal life. Although unassuming, Wigner's
Hungarian accent, singular style, and unmatched scientific ability
made him a rare personality. To Wigner, a piece of work was
"amusing" if right and symmetrical but "interesting" if disorderly
and wrong. People at Oak Ridge, as elsewhere, found it impossible
to enter a doorway after him, because he always opened doors for
them, holding the portal ajar for others to emerge triumphant.
Widely admired and loved, Wigner was a scientific genius of rare
human kindness.
ORNL AND TVA: PARTNERSHIP FOR EAST TENNESSEE
Ten years and 40 miles separate the two institutions. One was
born during the Great Depression as a government-sponsored social
experiment that uplifted the nation's most economically depressed
region; the other was created in secrecy to produce the atomic bomb
before the Nazi war machine could beat the United States to it.
At first glance, the Tennessee Valley Authority (TVA) and Oak Ridge
National Laboratory (ORNL) seem to have little in common. But they
share a common geography (East Tennessee) and a common political
heritage (both are products of the Franklin Roosevelt
administration). Most importantly, TVA and the Laboratory have
provided the scientific infrastructure responsible for the region's
international reputation in two related fields: water and energy.
When TVA arrived in May 1933, the Tennessee Valley was plagued by
an unruly river that drained the region's economic vitality by
flooding its farms and cities. East Tennessee farmers, for example,
earned less than $100 a year, and 90% of them had no electricity.
TVA not only harnessed the river and electrified the valley, it
also boosted the region's wage rate in 1933 by offering laborers $1
a day.
When the nuclear project entered the valley under a cloak of
secrecy in the fall of 1942, perhaps no other region of the nation
had fewer scientists or less sophisticated laboratory equipment. In
fact, government investigators seeking a location for top-secret,
war-related research found East Tennessee's isolation one of its
prime attractions (another was cheap and abundant TVA electricity).
The Laboratory's presence drew top scientists to the region and
provided well-paying jobs for machinists, plumbers, and other
craftspeople. For many East Tennessee women, the Laboratory offered
their first opportunity to work outside the home.
The impacts of TVA and the Laboratory extended far beyond the
construction of dams, office buildings, and scientific facilities.
Spurred by soup lines at home and by Nazi armies conquering most of
Europe, the two institutions launched a socioeconomic revolution in
a remote region of the country that 20th-century technology had
left behind.
TVA and the Laboratory, as centers of scientific research and
technical application, have continued to join forces in projects of
common concern. In the 1960s, the Laboratory's abiding interest in
commercial nuclear power aided TVA's efforts to become one of the
nation's largest nuclear utilities. In the 1970s, the two
institutions joined hands in the failed effort to build the Clinch
River Breeder Reactor. In the 1980s, together with the University
of Tennessee, they formed a consortium of research institutions,
which was designed to bring the region's scientific and technical
experts closer together in an effort to better address regional and
global issues related to energy and the environment. In the 1990s
the three institutions continue to collaborate under the newly
formed Joint Institute for Energy and the Environment.
TVA and the Laboratory's positive impact on East Tennessee cannot
be overlooked. Their scientific and technological activities have
touched every hill and valley of the region. The two institutions
helped transform East Tennessee from an isolated, depressed region
into an international center for energy and environmental research.
LESLIE R. GROVES: MANHATTAN PROJECT'S MAIN MAN
In September 1942, Brigadier General Leslie R. Groves took
charge of the Manhattan Project. His influence was to be felt far
and wide by people swept into service for this top secret project.
In Oak Ridge, in the red mud and yellow dust, he was the driving
force behind the construction and operation of the large wartime
plants that would come to define the "Atomic City."
Groves is remembered for his management style and personality
traits. Those who liked him recall that he was hard-driving,
courageous, tough, responsible, and efficient. They say he demanded
respect and got the job done. Those less fond of his style
remember him as blunt, impatient, ruthless, tyrannical, severe, and
inconsiderate. For them, he was a strict taskmaster.
The day before he came to Oak Ridge, Groves was in a meeting with
Secretary of War Henry Stimson. By age and rank, Groves was the
junior person. Stimson proposed a committee of seven to nine
persons to run the Manhattan Project; Groves countered that such a
committee would be inefficient and proposed a committee of three.
After some discussion, the group accepted Groves' suggestion. Then,
in the presence of his superiors, Groves abruptly excused himself
from the meeting, saying he had to take the train to Oak Ridge to
select a site for the first atomic plant.
On September 19, 1942, Groves met with Colonel James Marshall and
inspected the site in Oak Ridge. Groves was pleased with the site
because it offered abundant electrical power and water, good access
by road and train, a sparse population, a nearby source of labor,
and a mild climate that made outdoor work possible year round.
Although scientific research leading to industrial production of
fissionable material was not yet complete, Groves decided to take
a chance on constructing uranium-235 production plants in Oak
Ridge. To accomplish this task, some 59,000 acres were purchased
at a cost of $60 to $70 per acre.
During the war, Groves frequently visited Oak Ridge, staying at a
special suite permanently reserved for him in the Guest House, now
the Alexander Motor Inn. When the hotel was booked up, guests were
allowed to stay in the general's suite provided that they agreed to
leave if he should show up (he sometimes arrived in the middle of
the night).
Besides production of enriched uranium through electromagnetic
separation and gaseous diffusion, which was done at Oak Ridge,
another goal of the Manhattan Project was to produce plutonium
through transmutation of uranium. Although the Graphite Reactor was
a pilot plant for creating plutonium, Groves ruled out Oak Ridge as
a major site for large-scale plutonium production. He was concerned
about the proximity of the site to Knoxville and the possibility,
however remote, of a reactor explosion that might endanger
Knoxville.
Groves, a native of Albany, New York, who graduated fourth in his
class from the U.S. Military Academy, headed the Manhattan Engineer
District for three years. He retired from the Army in 1948 with the
rank of lieutenant general and wrote several books, including Now
It Can Be Told: The Story of the Manhattan Project. He served as a
vice president of the Sperry Rand Corporation until 1961 and died
in 1970 in Washington, D.C.
SAFETY MARGINS
A major concern of Clinton Laboratories during the war was the
potential effect of radiation on health. The Oak Ridge facility
hired health physicists who monitored radiation throughout the X-10
area, introduced measures for personnel safety, and conducted
research on radiation and its effects. Caged rodents were placed
near the reactor to detect the effects of any escaping radiation.
Despite these precautions, the rush to meet deadlines and aid the
war effort sometimes led to radiation overexposures.
A victim of one of the largest radiation exposures during the war
was Martin Whitaker, director of Clinton Laboratories. On the west
side of the Graphite Reactor was a large opening through the
concrete shield to the graphite-uranium pile. Materials such as
shielding samples were placed in the opening to test their ability
to stop radiation. When testing was not under way, water was pumped
into a tank in the opening to block the radiation.
While escorting dignitaries from Washington, D.C., on an inspection
of the Graphite Reactor in 1944, Martin Whitaker ignored "No
Admittance" signs and took the visitors past the front of the tank,
thinking it full of water. Unfortunately, it had been drained. The
exposure to radiation could be only estimated, not measured,
because no one in the group wore a dosimeter. The chief health
physicist later called this debacle a blessing in disguise, because
health physics regulations thereafter became mandatory at Clinton
Laboratories.
THE SILVER LINING OF THE CALUTRONS
The 1100 calutrons at the Oak Ridge Y-12 Plant that provided the
explosive power for the first atomic bomb eventually achieved
incredible economic value. In 1943 the AEC borrowed 14,700 tons of
precious silver from the U.S. Treasury to use as electrical
conductors in bus bars and windings for the calutrons' magnets. The
silver was borrowed because of the wartime shortage of copper.
In a series of shipments from the late 1940s through the early
1950s, almost 12,500 tons of silver were returned to the U.S.
Treasury. In 1968 most of the remaining silver was returned,
leaving only 70 tons for four calutrons being used by the
Laboratory to produce samples highly enriched in stable isotopes.
The 1968 market value of the returned 2145 tons of silver was $124
million!
(keywords: Oak Ridge National Laboratory, history)
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Date Posted: 2/22/94 (ktb)