At the core of history: Iowa and the atomic bomb

The movie “Oppenheimer,” telling the story of Julius Robert Oppenheimer, the physicist who helped develop the process of controlled nuclear fission and later was put on trial for treason as a suspected Russian Communist spy, will premier in theaters the third week of July to correlate with the 78th anniversary of the first test of an atomic bomb.

The concept of ramming neutrons at very high speeds into other atoms and splitting the nucleus of those atoms creating two where there had been one, was first conceived in Germany in 1938. After the armies of Adolf Hitler, invaded Poland in 1939, the U.S. Army assembled a panel of the Allies’ most brilliant metallurgists and physicists, including Niels Bohr, originally of Denmark, who in the 1920s founded the concept of quantum physics, Arthur Compton, of the University of Chicago, who was considered the leading expert on radiation, or X-rays, from rare metals or minerals, and Oppenheimer.

One other expert, seldom mentioned, but in the same league as the above legends, was Frank Spedding. Spedding was born in Canada in 1902, studied under Niels Bohr, and at the age of thirty-nine, was hired by Iowa State University as a Professor of Physical Chemistry.

Acknowledged as one of the pioneering researchers in the chemical (atomic) elements of minerals, he was recruited by the Army and its nuclear program, known as the Manhattan Project, to find a process that could purify the mineral uranium so that it would have a high enough concentration of protons to split and produce heat.

Spedding immediately set up a research center at Iowa State, which came to be popularly known as the Ames Laboratory. There, he and his team of scientists and students perfected a procedure of adding an element known as UF-4 along with calcium to uranium 238 in vacuum tubes, then heating it and removing the calcium. This created sixty percent pure uranium.

The uranium, enriched, as it was called at that point, was then loaded on trucks and delivered to the University of Chicago where Compton was building a vessel to hold the uranium and achieve the world’s first controlled nuclear reaction.

The site chosen for this experiment was located in a vacant space beneath the grandstand of the football stadium at Chicago’s south side university. Interestingly, the author of this column first learned of this when, in the 1990s, I met Fred Olivi.

Olivi was a resident of Chicago’s south side and was asked to stand watch over the bleachers of the stadium at night, having no idea what was happening beneath him. Ironically, three years later, as a Colonel in the Army Air Force, he, by sheer coincidence, was to be the co-pilot of Bock’s Car, the B-29 bomber that dropped the second atomic bomb.

The superstructure of the vessel at the University of Chicago, titled Atomic Pile Number One, was about 25 feet tall and made of thick stacks of graphite. The uranium would be placed in the vessel and submerged in water. The water was necessary because when the neutrons collide with the atoms and split them, it creates intense rays of radiation with temperatures of nearly 2,000 degrees Fahrenheit. Graphite, however, helps to block the radiation and its rays, containing the level of heat.

On the afternoon of Dec. 2, 1942, a crew of forty-nine scientists, of which Spedding was invited, watched as rods of cadmium were slowly withdrawn from the water and the uranium. Cadmium absorbs neutrons, so as the rods were pulled out, the number of neutron collisions increased until, at 3:53 p.m., a state called critical mass had been reached. For the first time ever, a man made sustained controlled nuclear reaction had been achieved.

The first use of the technology was to concentrate uranium in a shell of steel and design a firing mechanism that would shoot neutrons into the uranium, but with no cadmium or graphite, the heat created would simply burst through the metal and be released in a massive reaction.

On Aug. 6, 1945, this was done when, in order to end World War II, a “gadget,” as it was known, was dropped from a B-29 bomber and unleashed heat in excess of 7,000 degrees, then produced a mushroom cloud 50,000 feet tall.

When Japan did not surrender, this was followed by another (containing the element plutonium), on the mission flown by Colonel Olivi, on Aug. 9. The Japanese surrendered a month and a half later.

The second use of atomic reactions was for the production of electricity. The heat would boil water which turned to steam and the steam would, at high speed, spin magnets that generated electrical power.

Oppenheimer, however, feared that if only one country held the technology, it could lead to future use as a weapon once again. Believing that a balance of power was the only way to keep the peace, he and a few other scientists, were accused of having sympathies for the Russians (the second superpower after the fall of Germany and Japan) and being members of the Communist Party.

Oppenheimer was stripped of his security clearance and effectively barred from practicing physics within the United States government. He was later exonerated in 2022 when the Secretary of Energy declared that he was treated unfairly and that the trial was biased. He died, of cancer, in 1967.

Spedding, after the war, continued at Iowa State University, and in 1947, organized his research center, formally titling it the Ames Laboratory. He remained its Director for twenty years adding as many as 12,000 employees. It is today operated on the university campus, by the Department of Energy. Spedding, himself, died of a stroke, in 1984.

So, as you view the movie Oppenheimer this summer, remember not just the drama of its primary character and namesake, but that of Frank Spedding, without whom Oppenheimer and his team, would not have accomplished what they did. It was an Iowan who helped them usher in the nuclear age.

As a sidelight, and in the interest of full disclosure, two decades ago, the Department of Energy presented me with a section of graphite from Atomic Pile Number One. I am proud to have it in my collections and pleased to relate that the only thing it radiates is memories of my friendship with Colonel Olivi.

David V. Wendell is a Marion historian, author and special events coordinator specializing in American history.