MANHATTAN PROJECT, THE NUCLEAR AGE BEGINS

Trinity Test, the Manhattan Project

Today, The Grandma has visited Norah, an old friend from Venezuela who lives now in Barcelona. They have been talking about Mount Carmel, the coastal mountain range in northern Israel, and about the Apollo 11 which carried the first crewed lunar landing mission on a day like today in 1969.

The Saturn V SA-506 carrying Apollo 11, the first crewed lunar landing mission, on July 16, 1969, at 13:32 UTC. Launching from Launch Pad 39A at Florida's Kennedy Space Center, the five Rocketdyne F-1 engines of the rocket's S-IC first stage can be seen arrayed in a quincunx, with a fixed centre engine and four outer engines that gimballed for steering.

The USA wrote incredible stories in our world history. The Apollo 11 was one of them, but The Grandma has also wanted to remember another story that shows how science sometimes can play against the interests of the Humanity. It is the story of the Manhattan Project, a project also started in the USA twenty-seven years before the Apollo 11 arrived to the Moon, a project which is considered the beginning of the nuclear age.

The Manhattan Project was a research and development undertaking during World War II that produced the first nuclear weapons. 

It was led by the United States with the support of the United Kingdom and Canada. From 1942 to 1946, the project was under the direction of Major General Leslie Groves of the U.S. Army Corps of Engineers. Nuclear physicist Robert Oppenheimer was the director of the Los Alamos Laboratory that designed the actual bombs.

The Army component of the project was designated the Manhattan District; Manhattan gradually superseded the official codename, Development of Substitute Materials, for the entire project. Along the way, the project absorbed its earlier British counterpart, Tube Alloys.

The Gadget, the Manhattan Project

The Manhattan Project began modestly in 1939, but grew to employ more than 130,000 people and cost nearly US$2 billion, about $23 billion in 2018 dollars. Over 90% of the cost was for building factories and to produce fissile material, with less than 10% for development and production of the weapons.

Research and production took place at more than 30 sites across the United States, the United Kingdom, and Canada.

Two types of atomic bombs were developed concurrently during the war: a relatively simple gun-type fission weapon and a more complex implosion-type nuclear weapon. The Thin Man gun-type design proved impractical to use with plutonium, and therefore a simpler gun-type called Little Boy was developed that used uranium-235, an isotope that makes up only 0.7 percent of natural uranium. Chemically identical to the most common isotope, uranium-238, and with almost the same mass, it proved difficult to separate the two. Three methods were employed for uranium enrichment: electromagnetic, gaseous and thermal. Most of this work was performed at the Clinton Engineer Works at Oak Ridge, Tennessee.

In parallel with the work on uranium was an effort to produce plutonium. After the feasibility of the world's first artificial nuclear reactor was demonstrated in Chicago at the Metallurgical Laboratory, it designed the X-10 Graphite Reactor at Oak Ridge and the production reactors in Hanford, Washington, in which uranium was irradiated and transmuted into plutonium. The plutonium was then chemically separated from the uranium, using the bismuth phosphate process. The Fat Man plutonium implosion-type weapon was developed in a concerted design and development effort by the Los Alamos Laboratory.

More information: US Departament of Energy

The project was also charged with gathering intelligence on the German nuclear weapon project.

Through Operation Alsos, Manhattan Project personnel served in Europe, sometimes behind enemy lines, where they gathered nuclear materials and documents, and rounded up German scientists. Despite the Manhattan Project's tight security, Soviet atomic spies successfully penetrated the program.

The Manhattan Project Sites

The first nuclear device ever detonated was an implosion-type bomb at the Trinity test, conducted at New Mexico's Alamogordo Bombing and Gunnery Range on 16 July 1945.

Little Boy and Fat Man bombs were used a month later in the atomic bombings of Hiroshima and Nagasaki, respectively. In the immediate postwar years, the Manhattan Project conducted weapons testing at Bikini Atoll as part of Operation Crossroads, developed new weapons, promoted the development of the network of national laboratories, supported medical research into radiology and laid the foundations for the nuclear navy. It maintained control over American atomic weapons research and production until the formation of the United States Atomic Energy Commission in January 1947.

More information: Atomic Heritage Foundation

The discovery of nuclear fission by German chemists Otto Hahn and Fritz Strassmann in 1938, and its theoretical explanation by Lise Meitner and Otto Frisch, made the development of an atomic bomb a theoretical possibility. There were fears that a German atomic bomb project would develop one first, especially among scientists who were refugees from Nazi Germany and other fascist countries.

 

In August 1939, Hungarian-born physicists Leó Szilárd and Eugene Wigner drafted the Einstein–Szilárd letter, which warned of the potential development of extremely powerful bombs of a new type. It urged the United States to take steps to acquire stockpiles of uranium ore and accelerate the research of Enrico Fermi and others into nuclear chain reactions. They had it signed by Albert Einstein and delivered to President Franklin D. Roosevelt. Roosevelt called on Lyman Briggs of the National Bureau of Standards to head the Advisory Committee on Uranium to investigate the issues raised by the letter. Briggs held a meeting on 21 October 1939, which was attended by Szilárd, Wigner and Edward Teller. The committee reported back to Roosevelt in November that uranium would provide a possible source of bombs with a destructiveness vastly greater than anything now known.

More information: SBS 

The Advisory Committee on Uranium became the National Defense Research Committee (NDRC) on Uranium when that organization was formed on 27 June 1940. Briggs proposed spending $167,000 on research into uranium, particularly the uranium-235 isotope, and the recently discovered plutonium.

On 28 June 1941, Roosevelt signed Executive Order 8807, which created the Office of Scientific Research and Development (OSRD), with Vannevar Bush as its director. The office was empowered to engage in large engineering projects in addition to research. The NDRC Committee on Uranium became the S-1 Section of the OSRD; the word uranium was dropped for security reasons.

At 05:30 on 16 July 1945 a gadget exploded with an energy equivalent of around 20 kilotons of TNT, leaving a crater of Trinitite -radioactive glass- in the desert 76 m wide. The shock wave was felt over 160 km away, and the mushroom cloud reached 12.1 km in height. It was heard as far away as El Paso, Texas, so Groves issued a cover story about an ammunition magazine explosion at Alamogordo Field.

More information: Rare Historical Photos

The Atomic Age was born in secrecy, 

and for two decades after Hiroshima, 

he high priests of the cult of the atom 

concealed vital information 

about the risks to human health posed by radiation.

Stuart Udall