Skip to comments.A Los Alamos Story Worthy of Stephen King (The Plutonium 239 Demon Core)
Posted on 07/26/2012 8:37:22 PM PDT by DogByte6RER
click here to read article
FYI ... some more references:
The Curse of the Demon Core
The Manhattan Project’s Fatal “Demon Core”
The Demon Core
I have to say that was a very interesting read.
Thanks for posting it ^^
www.orau.org/ptp/Library/accidents/la-13638.pdf is heavy but fascinating reading of all the criticality accidents all around the world, especially including the US and the Soviet Union, but also elsewhere. It’s dry and technical, but includes excerpts of interviews and (doomed) people’s notes aware of their own fate. It also includes reconstructions of what happened, in detail. Very technical, but fascinating to those inclined to such things. It’s also very long, to the tune of hundreds of pages.
Louis Slotin was one hell of a guy.
Sounds like suicide by hubris to me. There's nothing mysterious about disregarding basic safety precautions. I admit that radiation dangers probably weren't completely understood in those days but I'm sure both of those geniuses knew what had happened to Madame Curie.
From the Wikipedia:
On May 21, 1946, with seven colleagues watching, Slotin performed an experiment that involved the creation of one of the first steps of a fission reaction by placing two half-spheres of beryllium (a neutron reflector) around a plutonium core. The experiment used the same 6.2-kilogram (13.7 lb) plutonium core that had irradiated Harry K. Daghlian, Jr., later called the "Demon core" for its role in the two accidents. Slotin grasped the upper beryllium hemisphere with his left hand through a thumb hole at the top while he maintained the separation of the half-spheres using the blade of a screwdriver with his right hand, having removed the shims normally used. Using a screwdriver was not a normal part of the experimental protocol.
At 3:20 p.m., the screwdriver slipped and the upper beryllium hemisphere fell, causing a "prompt critical" reaction and a burst of hard radiation. At the time, the scientists in the room observed the blue glow of air ionization and felt a heat wave. In addition, Slotin experienced a sour taste in his mouth and an intense burning sensation in his left hand. Slotin instinctively jerked his left hand upward, lifting the upper beryllium hemisphere and dropping it to the floor, ending the reaction. However, he had already been exposed to a lethal dose of neutron radiation.
As soon as Slotin left the building, he vomited, a common reaction from exposure to extremely intense ionizing radiation. Slotin's colleagues rushed him to the hospital, but irreversible damage had already been done. His parents were informed of their son's inevitable death. A number of volunteers donated blood for transfusions, but the efforts proved futile. Slotin died nine days later on May 30, in the presence of his parents. He was buried in Winnipeg on June 2, 1946.
The core involved was subject to a number of experiments shortly after the end of the war and was used in the Able detonation, during the Crossroads series of nuclear weapon testing. Slotin's experiment was said to be the last conducted before the core's detonation and was intended to be the final demonstration of its ability to go critical.
The accident ended all hands-on critical assembly work at Los Alamos. Future criticality testing of fissile cores was done with special remotely controlled machines, such as the "Godiva" series, with the operator located a safe distance away to prevent harm in case of accidents.
Among the seven observers, two suffered from acute radiation syndrome but recovered. Years later, three of the observers eventually died of conditions that are known to be promoted by radiation, as did a security guard who was nearby during Daghlian's accident. Although some of those deaths were probably latent stochastic (random) effects of the accident, it is not possible to draw any definitive conclusions from such a small sample set.
Daghlian and Slotkin’s accidents were recreated in the film “Fatman and Little Boy.” Bad way to go.
I’ll just visualize pop rocks.
I thought the tampers and neutron reflectors were part of the core assembly in the early bombs? Need to go read the "Making of the Atomic Bomb" again, though I just reread it a rew weeks ago.
Ping for later reading.
Richard Feynman called these experiments “tickling the tail of a sleeping dragon.”
Photo caption: At This Point, Our Picnic Ended
Criticality is dependent on mass, purity and density. You're thinking of a supercritical explosion. Criticality is simply a self-sustaining nuclear reaction. In a bomb, masses of radioactive material which would go critical if placed together, are split and kept apart. Then they are slammed together (very precisely) by explosives to shove them into a supercritical (explosive) state themselves. In a fission bomb, high explosives do the slamming (2 stages). In a fusion bomb, high explosives start a fission bomb, which then slams even higher potential nuclear fuel together into a fusion reaction (3 stages).
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