That new thing was the first-ever manmade nuclear
explosion. Recognizing its world-changing significance, J. Robert
Oppenheimer, the physicist who led its development, had given the test
a name with religious overtones: “Trinity.”
Trinity would be followed in less than a month by the dropping of
atomic bombs on the Japanese cities of Hiroshima and Nagasaki—killing
more than 150,000 people, hastening the end of World War II, and
forever cleaving history in two. Like all moments that signal the dawn
of a new age, Trinity came to be seen, as Rabi forecast, as a beginning
more than an end. Largely lost in the bomb’s dark shadow has been the
monumental effort that led to its creation: the Manhattan Project,
almost certainly the most ambitious research and industrial undertaking
mounted by the human race to that day.
The Manhattan Project involved more than 600,000 people, including city
planners, soldiers, construction workers, technicians, craftsmen,
clerks, secretaries, teachers, doctors, and some of the brightest
scientific minds of the time. Miles of America were cleared of farms
and residences so that entire new cities could be built. Oak Ridge,
Tennessee; Los Alamos, New Mexico; and Hanford, Washington sprung up
and became full-fledged communities seemingly overnight, with schools
and Boy Scout troops and weekend dances for the thousands of people who
flocked to the jobs the cities offered—all without officially existing
on any map. The project was both massive and top secret. Among the
thousands of men and women who worked on it, only a relative handful
knew what they were trying to achieve. Security was so tight that
knowledge of the project was even kept from Vice President Harry S.
Truman.
The United States was the only nation on Earth that could have pulled
it off. No other country had both the intellectual resources (bolstered
by the participation of British and other foreign scientists) and the
industrial might. Yet as Richard Rhodes noted in the 25th anniversary
edition of his definitive history book The Making of the Atomic Bomb,
“More than seven decades after its conception … the Manhattan Project
is fading into myth.”
The
Manhattan
Project National Historical Park was created to make sure that
doesn’t happen. The National Trust, along with the
National Parks Conservation Association,
the
Atomic
Heritage Foundation, and other organizations, played a key role in
advocating for the park, which addresses the bomb’s tragic consequences
as well as its creation. “Our purpose from the beginning was to say
that this was a very important era in American history,” says Nancy
Tinker, a National Trust senior field officer who helped lead the
effort as part of the Trust’s
National
Treasures campaign. “It’s an opportunity to tell very complex parts
of this story from everybody’s perspective.”
“Twenty-two thousand people were
here.
Probably about 100 of them knew what they were doing.”
Ray Smith
Authorized in 2014 through an act of Congress and officially
established in 2015, the park has units at Oak Ridge, Los Alamos, and
Hanford. The three sites are central to the development of the atomic
bomb, nuclear power, and a surprising number of inventions we count on
today (including the field of nuclear medicine, which uses radiation
for diagnosis and treatment). Among the three locations, the park
provides a chance to explore the science and technology behind this
massive operation, along with the lives of those who made it happen.
Most important, it helps to preserve key facilities at all three sites,
ensuring that an essential part of the American story—the world’s
story, really—doesn’t disappear from view.
“National Park” may still conjure up images of towering mountains,
verdant forests, and dizzying canyons, but the National Park Service
has placed an increasing emphasis on reflecting the nation’s more
diverse urban and industrial heritage. Regional Director Sue Masica,
who oversees the new park, says it’s all part of the Park Service’s
role as “the nation’s storyteller.”
As the United States cleaned up old sites from the Manhattan Project
and the Cold War, many of the buildings that told that story were torn
down. This legacy will now be preserved. Earlier this year, I went to
take a look at a place that holds several of the most historic
surviving facilities: Oak Ridge, Tennessee, the “secret city” that
during the war grew from around 1,000 people to more than 75,000, all
within a fenced perimeter that could only be entered through carefully
guarded gates.

A calutron "racetrack" at the Y-12 plant used strips of silver as part
of the uranium refining process
U.S. Department of Energy/Oak
Ridge Public Library

A calutron "racetrack" at the Y-12 plant used strips of silver as part
of the uranium refining process
American Museum of Science
and Energy

Aerial view of the Y-12 facility in 1947
U.S. Department of Energy

Workers load uranium into the X-10 graphite reactor
U.S. Department of Energy

A demonstration of mechanical hands at Oak Ridge in 1949
U.S. Department of Energy
If you’re a science nerd, and I freely confess I
am, there is something wonderful about the technology of the 1940s.
Unlike today’s sleek glass-and-aluminum gadgets, it’s big and heavy and
advertises its significance in a profusion of dials and levers. So it
was with uncomplicated delight that I found myself standing inside a
cavernous room staring at opposing banks of gray control panels
stretching back into the shadows, each one properly festooned with
old-fashioned controls.
“This is exactly like it looked in 1945,” Ray Smith tells me. Smith has
worked at the Y-12 National Security Complex in Oak Ridge for 45 years,
most recently as its official historian. A big man with a shock of
unruly salt-and-pepper hair, bright eyes, and a boyish smile that makes
him a natural tour guide, Smith says he’s “poked his nose into every
nook and cranny” of the Y-12 plant over the years. His pleasure in
sharing its historic treasures is evident.
The control panels we are staring at were for “calutrons,” which
separated weapons-grade uranium-235 out of heavier uranium-238 through
the use of powerful electric and magnetic fields. Each calutron yielded
only a very small amount of enriched uranium, and the process had to be
repeated to obtain the necessary purity, so the government built 1,152
calutrons at Oak Ridge. The magnets at the heart of the machines
required so much conductive metal that the project borrowed 14,700 tons
of silver from the U.S. Treasury’s reserves.
Yet the 1943 calutron building wasn’t even the biggest facility at the
Oak Ridge site during the war. That was the gaseous diffusion plant,
K-25, which used a different approach to enriching uranium. (There were
three approaches to enriching uranium, the third being liquid thermal
diffusion. No one was sure which would work best, so Gen. Leslie
Groves, the Manhattan Project’s military commander, decided to try them
all.) The U-shaped gaseous diffusion plant, which was torn down in 2013
after sitting abandoned for decades, consisted of two half-mile-long
wings that each measured 400 feet wide—the world’s largest building at
the time of its completion in 1945.
A tour of any unit of the Manhattan Project park is a tour of
superlatives: the “first” this, the “biggest” that, repeated over and
over again. Yet it is also a profoundly human story. The young women
who operated the calutrons came from around the South, drawn by the
jobs and a chance to be part of the war effort and something they could
sense was very big, even if none of them knew what it was. Most
employees were told no more than what they needed to know to do their
jobs, and were prohibited from even talking about that.
“Twenty-two thousand people were here,” says Smith of the Y-12
facility. “Probably about 100 of them knew what they were doing.”
Some of those who did know worked on the world’s first continuously
operating industrial-size nuclear reactor. The now-inoperative X-10
Graphite Reactor at the Oak Ridge National Laboratory has been a
National Historic Landmark since 1966. It’s open to the public as part
of the bus tours of the park’s Oak Ridge unit. On display is the
original logbook in which scientists monitoring the reactor noted the
moment the nuclear reaction became self-sustaining. A hand-written,
circled note written shortly after 5 a.m. on November 4, 1943, reads:
“Critical reached!”
The casual nature of that note, scrawled on lined, yellowing paper,
stopped me. It was like stumbling upon a record of the discovery of
fire. The excitement evident in the cursive script and the exclamation
point again brought home the very human nature of the Manhattan
Project—our desire to be part of something bigger than ourselves, the
inexhaustible human curiosity that leads us down new paths, both good
and bad. These were the most brilliant minds of their time, but they
were working with slide rules—not computers—and making much of it up as
they went along. The entire concept of nuclear fission had been
discovered only five years earlier, in Nazi Germany.
In the city of Oak Ridge, I find a hidden gem of a museum. The American
Museum of Science and Energy is the departure point for tours of the
Manhattan Project park facilities on U.S. Department of Energy
property. But more than that, it contains a set of impressive exhibits
on the history of atomic energy and Oak Ridge’s role in the Manhattan
Project. One, “The Story of Oak Ridge,” smartly focuses much of its
attention on the lives of the men and women who worked at the site.
The exhibit includes one of the 1,622 “B-1” prefabricated houses built
for residents of the town. They were flat-topped Midcentury
Modern–style houses, only 576 square feet but efficiently planned and
filled with light. Standing inside the B-1, thinking about the smiling
young workers captured in photographs, I consider the irony that a
place where the good life started for so many Americans was the same
place where the destructive power of the atomic bomb began.

Oak Ridge National Laboratory today
U.S. Department of Energy Oak
Ridge National Laboratory

Y-12 Historian Ray Smith
National Nuclear
Security Administration

"B-1" prefabricated house in Oak Ridge
U.S. Department of Energy/Oak
Ridge Public Library

Tulip Town grocery store in Oak Ridge
U.S. Department of
Energy/Oak Ridge Public Library

The Oak Ridge Boy Scouts celebrate Memorial Day in 1947
U.S. Department of Energy

The Hanford, Washington, site in 1999
Joel Rogers

Fuller Lodge in Los Alamos, New Mexico
Leslie Bucklin
The Manhattan Project park is a partnership between the Department of
Energy and the National Park Service; the DOE continues to operate
active facilities at both Los Alamos and Oak Ridge. The sprawling Y-12
complex, for example, still handles nuclear material for the DOE’s
National Nuclear Security Administration. Security is an understandable
priority.
Figuring out how to increase public access to some of the sites is a
work in progress. The Hanford reactor site in Washington State is open
for tours from March to November, but historic sites within the DOE
facilities at Los Alamos, where extensive scientific research
continues, won’t be open to visitors this year. Still, “there’s
something to see at every site,” says Sue Masica.
The city of Los Alamos offers a walking tour that includes
Oppenheimer’s house and the Fuller Lodge, which served as temporary
housing for some of the 6,000 physicists, mathematicians, engineers,
support personnel, and their families who relocated to Los Alamos.
Fuller Lodge was once part of the Los Alamos Ranch School for boys,
located on a remote New Mexico mesa. (If you’re going to test the
world’s first atomic bomb and you’re not exactly sure how big the
explosion will be, remote is key.)
Oak Ridge, too, is working to make sure the city integrates its
historic attractions—including the Alexander Inn, where Oppenheimer and
other dignitaries stayed, and the town’s multi-denominational Chapel on
the Hill—with the park experience. “The museum will be the hub. From
there, you’ll be able to take tours to Y-12 and the Oak Ridge
laboratory, and then you’ll be able to get your orientation and head
out into the town to see the historic sites we have here,” says Mark
Watson, city manager.
The sites are just one more part of a complex story. “At its core, it’s
the development of the nuclear weapon that was the purpose of the
Manhattan Project,” says Masica. “But as you peel the onion, you
realize there are so many nuances to that story—stories of
industrialization, stories of women in the workforce, stories of the
people displaced by the project. There’s so much connected to it.”
Smith points to the many technological offshoots that came from the
project, which include everything from elements in today’s smartphone
touchscreens to Teflon. The insight into radioactive elements and an
improved understanding of their properties would have lasting
ramifications beyond weaponry. “The exact same science that created the
nuclear bomb also created nuclear medicine,” Smith says. “That’s an
underappreciated story.”
But of course, the goal was always to build the bombs dropped on
Hiroshima and Nagasaki, leaving both cities in ruin and more than
150,000 dead. Masica says this legacy, too, will be examined at the
park, which will include perspectives from Japan. The National Park
Service may be “the nation’s storyteller,” but at the Manhattan Project
National Historical Park, there is an understanding that this tale—a
story of both the tremendous ingenuity of the human race and its
capacity for destruction—is much more than just an American story.