Honoring the achievements and legacy of the WWII generation of nuclear pioneers — and remembering all those affected by Trinity.

By Craig H. Piercy, CEO and Executive Director of the American Nuclear Society
Eighty years ago today, at exactly 5:29:45 a.m. local time* on July 16, 1945, the United States Army detonated the world’s first nuclear bomb in the Jornada del Muerto desert of southern New Mexico. The searing flash and thunderous shockwave marked the culmination of the Manhattan Project, a secret, three-year national effort to harness nuclear fission and hasten the end of the Second World War.
The Trinity Test, overseen by Manhattan Project director Major General Leslie Groves and Los Alamos Laboratory director Dr. J. Robert Oppenheimer, was the final act of that race to build the atomic bomb. Hoisted atop a 100-foot steel tower, the plutonium implosion device, known as the Gadget, unleashed a blast equal to 21,000 tons of TNT and temperatures hotter than the center of the sun.
From ten miles away, observers wearing darkened welder goggles looked on in stunned silence. “We knew the world would not be the same,” recalled Oppenheimer.
Plaque honoring Frisch and Peierls at the University of Birmingham in England. (Photo: Anthony Cox)
The Manhattan Project is usually considered to have been initiated with Albert Einstein’s letter to President Franklin Roosevelt in October 1939. However, a lesser-known document that was just as impactful on wartime nuclear history was the so-called Frisch-Peierls memorandum. Prepared by two refugee physicists at the University of Birmingham in Britain in early 1940, this manuscript was the first technical description of nuclear weapons and their military, strategic, and ethical implications to reach high-level government officials on either side of the Atlantic. The memorandum triggered the initiation of the British wartime nuclear program, which later merged with the Manhattan Engineer District.
The Ion Beam Facility, center, at Technical Area 03 at LANL. (Photo: DOE)
Work has started at the Department of Energy’s Los Alamos National Laboratory in New Mexico to deactivate, decommission, and remove the Ion Beam Facility, which played a role in research and experiments that helped develop the nation’s nuclear arsenal during the 1950s and 1960s.
Construction crews work to erect the platform’s structural framework. (Photo: DOE)
Crews are making significant progress on the construction of the K-25 viewing platform at the Oak Ridge Reservation in Tennessee, the Department of Energy’s Office of Environmental Management announced on August 20. When completed next year, the elevated platform will offer a sweeping panoramic view of the massive 44-acre footprint of the K-25 Building, which once produced enriched uranium used in the weaponry that ended World War II.
The Argonne-West laboratory site before it was merged with the Idaho National Engineering and Environmental Laboratory into today’s Idaho National Laboratory. The silver dome in the photo is Experimental Breeder Reactor-II, the silver structure with the flat top and sloping sides is the Zero Power Plutonium Reactor, and the brown boxlike structure behind ZPPR is the Hot Fuel Examination Facility. (Photo: Argonne National Laboratory)
Idaho’s nuclear energy history is deep and rich. The National Reactor Testing Station (NRTS) began its history as an artillery testing range in the 1940s.1 Following World War II, Walter Zinn, Argonne National Laboratory’s founding director and Manhattan Project Chicago Pile-1 project manager, proposed to the Atomic Energy Commission that a remote location be found for building test reactors. In 1949, he and Roger S. Warner, AEC’s director of engineering,2 developed a list of potential sites from which the NRTS was selected. Over the decades, quite a few companies and AEC national laboratories built 52 experimental and test reactors at the NRTS, including 14 by Argonne.3 (For a brief AEC video on the NRTS, see youtube.com/watch?v=C458NsH08TI.)
The exterior of the Clementine nuclear reactor at Los Alamos Scientific Laboratory. (Photo: LANL)
In March 1949—75 years ago this month—the 25-kilowatt reactor known as Clementine reached full power. As an experimental reactor, it had a rather long and successful run. It was the world’s first fast neutron (high-energy) reactor and operated from initial criticality in 1946 to final shutdown in 1952.
Radioisotopes target cancer, improve imaging, and have myriad other medical uses
ORNL radioisotope manufacturing coordinator Jillene Sennon-Greene places a shipment vial of actinium-225 inside the dose calibrator to confirm its activity is within customer specifications. (Photo: Carlos Jones/ORNL, DOE)
On August 2, 1946, 1 millicurie of the isotope carbon-14 left Oak Ridge National Laboratory, bound for the Barnard Free Skin and Cancer Hospital in St. Louis, Mo.
That tiny amount of the radioisotope was purchased by the hospital for use in cancer studies. And it heralded a new peacetime mission for ORNL, built just a few years earlier for the production of plutonium from uranium for the Manhattan Project.
Front face of the B Reactor at the Hanford Site. (Photo: DOE)
In remote southeastern Washington you will find the sprawling Hanford Site, which was constructed to produce plutonium for the Manhattan Project. Within this complex is the first plutonium production reactor, the Hanford B Reactor. The DuPont Corporation was responsible for construction and operation of the B Reactor. Due to the urgency of the Manhattan Project, construction was completed in just over a year, and The B Reactor went critical on September 26, 1944. After the needs of the Manhattan Project were satisfied, the reactor was briefly shut down and then restarted to produce plutonium for roughly another 20 years, supporting Cold War efforts. In addition to plutonium production, the B Reactor also pioneered the process to produce tritium for the first-ever thermonuclear test.
A replica of the chianti bottle signed by many of those present on December 2, 1942, alongside the image of a document signed 20 years later by most of those present (Photo: ANL); a portion of a photo of CP-1 scientists taken on December 2, 1946 (Photo: ANL); January 1993 Nuclear News coverage of CP-1 50th anniversary commemorations during the 1992 ANS Winter Meeting.
Nuclear Newswire is back with the final #ThrowbackThursday post honoring the 80th anniversary of Chicago Pile-1 with offerings from past issues of Nuclear News. On November 17, we took a look at the lead-up to the first controlled nuclear chain reaction and on December 1, the events of December 2, 1942, the day a self-sustaining nuclear fission reaction was created and controlled inside a pile of graphite and uranium assembled on a squash court at the University of Chicago’s Stagg Field.