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submitted 1 week ago by fossilesque@lemmy.dbzer0.com to c/science_memes@mander.xyz

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[-] rekabis@programming.dev -2 points 6 days ago

Look into the Demon Core. Chunk of refined nuclear material that was perfectly fine to handle so long as it wasn’t bumped.

But bump it even slightly, and the part that got bumped became dense enough to experience a minor amount of sustained fission and throw off a lethal enough dose of radiation. Several scientists died because of it.

[-] princessnorah@lemmy.blahaj.zone 15 points 6 days ago

That's not at all what happened with the Demon Core. On its own, you could not do anything to it that would make it reach supercriticality. The experiments that were conducted on it involved neutron reflective materials. With the addition of neutrons back into the core, that pushed it closer and closer to criticality. Both incidents occurred when too much reflective material was added around the core and it reached supercriticality, a sustained chain reaction.

[-] NaibofTabr@infosec.pub 10 points 6 days ago

Yeah, for being brilliant physicists, they weren't particularly smart. From the second incident:

On May 21, 1946, one of Daghlian's colleagues, physicist Louis Slotin, was demonstrating a similar criticality experiment, lowering a beryllium dome over the core.

Like the tungsten carbide bricks before it, the beryllium dome reflected neutrons back at the core, pushing it toward criticality. Slotin was careful to ensure the dome – called a tamper – never completely covered the core, using a screwdriver to maintain a small gap, acting as a crucial valve to enable enough of the neutrons to escape.

The method worked, until it didn't.

The screwdriver slipped and the dome dropped, for an instant fully covering the demon core in a beryllium bubble bouncing too many neutrons back at it.

After an initial bout of nausea and vomiting, he at first seemed to recover in hospital, but within days was losing weight, experiencing abdominal pain, and began showing signs of mental confusion.

A press release issued by Los Alamos at the time described his condition as "three-dimensional sunburn".

https://www.sciencealert.com/the-chilling-story-of-the-demon-core-and-the-scientists-who-became-its-victims-plutonium-bomb-radiation-wwii