We should also remember the servicemen who died too young because of insufficient safety protocols for atomic testing.
Posted on 05/25/2026 8:30:59 AM PDT by Red Badger
For some unknown reason Byrnes yanked a control rod all the way out. They weighed about a hundred pounds. Maybe it was stuck? At any rate the reactor went critical in a millisecond and the whole thing blew sky high. Oops
The SL-1 incident was required reading when I was going through Naval Nuclear Power Training back in 1983.
We should also remember the servicemen who died too young because of insufficient safety protocols for atomic testing.
People didn’t know any better at the time. A poor excuse, but true............
There’s a lot of controversy as to why the control rod was withdrawn in such a manor.
I’m gonna go with plain, old fashioned ignorance............
What about the first responders who placed him in the ambulance and the morticians who placed him in the casket, weren’t they exposed to radiation too?
Secondary exposure probably not as serious............
https://en.wikipedia.org/wiki/Demon_core
Using his own unapproved protocol, Slotin did not place any shims. ... Enrico Fermi reportedly told Slotin and others they would be "dead within a year" if they continued performing the test in that manner. Scientists referred to this flirtation with a nuclear chain reaction as "tickling the dragon's tail", based on a remark by physicist Richard Feynman.Spoiler Alert: Slotin surveyed Fermi's warning by four months.
“weren’t they exposed to radiation too?”
Yes, they were exposed to radiation. Mckinley was radioactive, ambulance crew was radiated.
And the innocent civilian bystanders that had no knowledge of what they were doing. Marie Curie is an example.
During her pioneering experiments, the dangers of radiation were largely unknown. Curie routinely carried vials of radioactive isotopes in her pockets and handled them with her bare hands. Because of the radioactive residue on her body, Marie Curie was interred in a lead-lined coffin. In 1995, her remains were relocated and entombed in the Panthéon in Paris, France’s national mausoleum, where she rests alongside other French luminaries. Because these materials have extremely long half-lives, this heavy exposure permanently contaminated her personal belongings. Her laboratory notebooks, recipes, and even her cookbooks remain so radioactive that they are still stored in lead-lined boxes at the French National Library, requiring protective gear to be handled. She was hot in the worst kind of way.
wy69
Spc. Richard Leroy McKinley, Army Spc. John Arthur Byrnes and Navy Seabee Richard Carlton Legg were all killed by steam and radiation.
Shouldn’t the graves of Byrnes and Legg be the same as McKinley’s grave?
“alongside other French luminaries” although in her case, the luminary term is literal. 😁
https://www.findagrave.com/memorial/154385419/john_arthur-byrnes
https://www.findagrave.com/memorial/67718734/richard_carlton-legg
There was an excellent account of this incident in the book “Atomic Accidents
A History of Nuclear Meltdowns and Disasters; From the Ozark Mountains to Fukushima” by James Mahaffey.
(BTW, the book is amazingly entertaining for such a serious subject! )
In it, he discussed this incident at length, as P8riot mentioned, it is an area of interest to those (such as myself) who have some knowledge and exposure to radioactive isotopes.
In the book, he discusses that some people have speculated that John A. Byrnes, the youngest of the three men, may have been trying to prank the two others by pulling it out faster to get enough emissions to bombard the radiation dectectors and cause them to alarm.
This sounds insane, but this craziness of trying to scare someone by evoking a minute burst of gamma radiation was not unheard of in those days.
One of the pranks people used to play on each other at Los Alamos in the Manhattan project was to manually (using a large flathead screwdriver!!!) separate two halves of a hollow sphere of beryllium around a mass of fissionable material by wedging the flat of the screwdriver between the two halves and gently prying them apart so when the geometry of the sphere changed ever so slightly, it would begin to emit gamma radiation that was enough to trip the radiation detectors and begin emitting the characteristic sound of a geiger counter, which cause some people to nearly crap their pants! Apparently, it was a “trick” more than a few people did to others as a prank to alarm them.
This process was called “Tickling The Dragon”.
This process was discouraged, and there were established ways to do this that did NOT involve the flat head of a screwdriver.
One time, 35 year old Dr. Louis Slotin (a relatively young nuclear physicist) was demonstrating how to do this manually to an associate, bypassing all the safety precautions that would prevent an accident, and when he pried the heavy sphere apart with the screwdriver, the flat head of the screwdriver slipped and the entire upper sphere displaced and a fully critical radioactive event occurred.
There was a blue flash in the room (called Cherenkov Radiation) and Slotin knew exactly what happened and immediately put the two halves back together with his bare hands. He died an agonizing death which took nine days, and his hands and arms, which had severe vascular damage began to die and rot because they could get no blood.
There was speculation that at the SL-1 reactor that day, the young Byrnes wanted to tease the older Navy veteran Seabee Richard C. Legg (who was the team supervisor) by causing the alarm to go off. They speculated it was hard to pull up, so he gave it a good tug, and it came up all the way, with disastrous results.
Pretty grim stuff.
Well done!
You beat me to the story about the Curies!
One of the very few deadly nuclear accidents.
Nuclear energy is in general the safest energy source, but few accidents did happen.
Unfortunately, the media likes to overblow the danger of nukes.
No, the “Demon” core incidents - there were actually two - had nothing to do with a “prank”. It was a field expedient way around established precautions.
Slotin in particular was well known to be complacent, a bit reckless and not a strict adherent to nuclear safety or established procedure, and it killed him.
“Tickling the dragon” was yet another procedure entirely. It was a bit insane but they knew what they were doing.
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