The unintentional leak of the Trinity test

A hot and radioactive trail


By Beyond the Band of Brothers

Special Thanks to Bill Thomas

July 16, 1945 ushered in a new era of warfare with the Trinity test in New Mexico: the first detonation of a nuclear bomb, followed by the bombing of Hiroshima and Nagasaki three weeks later. Information about this new type of weapon was strictly controlled – even Harry S Truman, Roosevelt’s Vice President, was only informed about it after his predecessor’s death and his admittance into the Oval Office. Nevertheless, a company headquartered in the State of New York accidentally learned more about the bomb and its far-reaching effects than they were meant to.
The explosion a few seconds after detonation during the Trinity test
The exact dates are unknown but sometime in August the offices of Eastman Kodak, the famous producer of cameras and photographic film, got flooded with complaints about their radiographic film used for X-ray images. The complaints were about black spots on the undeveloped film or a fogging which rendered it unusable.
Ruined film from the stock in question
The problem was investigated by Julian H. Webb, a physicist in Kodak’s research department. Webb discovered that the film was affected by beta radiation, the type of radiation the phrase “radioactive contamination” usually refers to, coming from the strawboard plates used as stiffeners between plates of film. The strawboard was traced back to a batch produced on August 6, three weeks after Trinity, in a mill in Vincennes, Indiana.
Kodak’s headquarters in Rochester, New York
Radiographic film is sensitive not only to X-ray but also to other types of radiation. Furthermore, it can be easily ruined by scratching, dirt or exposure to light, so packaging for such film has to be produced with care. The paper and cardboard for film packaging was often produced in manufacturing plants that also created scientific instruments using radium, a naturally occurring radioactive element. In order to avoid exposing packaging materials to radium and ruining the film placed inside them, Kodak contracted several mills around the country to produce clean packaging materials.
Physicists at the Manhattan Project in Los Alamos. Oppenheimer is third from the left.
The Vincennes mill, however, appeared to be contaminated and not by radium. Webb determined that the radioactivity was caused by a previously unknown material with a half-life of about 30 days. He didn’t know at the time but what he found was Cerium-141, which has a half-life 32 and a half days and is produced in quantity by nuclear explosions, like the Trinity test. Webb also learned that the straw used for the strawboard could not have been the culprit: it had been stored indoors for a long time before use. Had it been contaminated before it was stored, the contaminant would have decayed well before the strawboard was produced.
A 0.4in by 0.4in chunk of natural Cerium. The isotope contaminating the strawboards only came in microscopic quantities.
While investigating, Webb learned that another strawboard shipment was also contaminated, which was produced at a mill in Tama, Iowa. The two towns are 450 miles away, so it was hard to explain how both sites could have been affected by the same thing. Webb realized that the only commonality was that both mills were situated next to a river. The conclusion was frightening: an unknown source of radioactivity got into the atmosphere and was carried far and wide by precipitation. We don’t know when and how exactly Webb learned that the ultimate source of the radioactivity was the Trinity test but a 1949 report written by him clearly alludes to it.
The Trinity fireball 16 milliseconds after detonation
This wasn’t the last time Kodak ran afoul of secret nuclear explosions. In January 1951, the new Nevada Proving Grounds hosted its first atomic test. Several days later and 2,500 miles away, a Geiger counter at Kodak’s New York state headquarters detected radiation in the fresh snow that was 25 times higher than normal. Afraid that their stock might get damaged again, Kodak contacted the Atomic Energy Commission, who offered vague reassurances and failed to do anything specific.
Atomic test at the Nevada Proving Grounds in late 1951, with exposed troops watching it from 6 miles away
In March, Kodak threatened to sue the U.S. government for damages to its film stock caused by this or future nuclear tests. This made the government a lot more willing to listen. They reached an agreement with the company: Webb, now head of Kodak’s physics department, would receive the classified information needed to avoid further contamination: test schedules, maps and the expected distribution of radioactive fallout. In exchange, the company would keep quiet about the matter.

The agreement saved Kodak’s stock but it did nothing for thousands of civilians all around the country who were exposed to radioactive fallout during the years of atmospheric nuclear tests. It is estimated that up to 75,000 cases of thyroid cancer have been caused by the nuclear program in the U.S. alone.

You can learn more about how World War II ushered in the nuclear age join us on our World War II tours scheduled for 2019.

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