Blue flash
May 22, 2016 5:28 PM   Subscribe

The demonstration began on the afternoon of May 21, 1946, at a secret laboratory tucked into a canyon some three miles from Los Alamos, New Mexico, the birthplace of the atom bomb. Louis Slotin, a Canadian physicist, was showing his colleagues how to bring the exposed core of a nuclear weapon nearly to the point of criticality, a tricky operation known as “tickling the dragon’s tail.” - The Demon Core and the Strange Death of Louis Slotin
posted by Artw (53 comments total) 34 users marked this as a favorite
 
There's actually a clip of this moment in the film Fat Man and Little Boy, with John Cusack as Slotin; although they play with the timing a bit and set it during the Manhattan Project itself, as part of the leadup to building the first atomic bombs. Presumably so they have a sort of cautionary tale.
posted by EmpressCallipygos at 5:38 PM on May 22, 2016 [7 favorites]


I know these were brilliant men working with a novel technology, but that experimental setup was surely worthy of the Darwin Award.
posted by ryanrs at 5:42 PM on May 22, 2016 [14 favorites]


I remember reading about this in elementary school; even then I was amazed at the cavalier attitude they took with fissile material. The Demon core has showed up here a few times, including this FPP.
posted by TedW at 5:43 PM on May 22, 2016


For further and more technical reading on the subject, check out a Review of Criticality Accidents, this incident is described on Page 74. This reference is a pretty complete list of accidents that occured in the western world and has a selection of events from the soviet side as well.

If morbid radiation stuff is your thing, consider checking out the United States Transuranium & Uranium Registries. Possibly the best setting for a B-movie never used as such, it houses the remains of those who inhaled or ingested radioactive material and who donated their bodies to science so that the biokinetics of various radionuclides could be better understood (e.g. how much ended up in the lungs vs. the bones etc.)
posted by Across the pale parabola of joy at 5:44 PM on May 22, 2016 [15 favorites]


[Pops up]
He was from Winnipeg!
[Pops back down]
posted by Alvy Ampersand at 5:45 PM on May 22, 2016 [24 favorites]


MeFi loves the Review of Criticality Accidents, not least for its unfavorable geometry.
posted by The Bellman at 5:46 PM on May 22, 2016 [3 favorites]


The plutonium pit that killed Daghlian and Slotin was originally nicknamed Rufus, but after the accidents it came to be called the demon core. The pits that killed tens of thousands in Hiroshima and Nagasaki, meanwhile, got no such pejorative monikers. Such is the difference, perhaps, between intended and unintended harm, between the core carefully assembled for the purpose of mass destruction and the core reserved for the realm of experiment.

Interesting
posted by TedW at 5:47 PM on May 22, 2016 [20 favorites]


This is a good occasion to ask yourself: am I including "now wedge a screwdriver in there" as part of some important work that I do? Shouldn't I use my screwdrivers only for driving screws, one might ask, and not for, say, keeping this plutonium assembly from going critical?
posted by thelonius at 5:55 PM on May 22, 2016 [83 favorites]


but that experimental setup was surely worthy of the Darwin Award.


Considering what the pile under Stagg Field looked like, it probably represented a significant advance in safety protocols.
posted by TheWhiteSkull at 5:59 PM on May 22, 2016 [19 favorites]


There was a similar criticality incident at a test reactor in Tokai, Japan in 1999. It's pretty amazing to consider.
posted by My Dad at 6:02 PM on May 22, 2016 [3 favorites]


This is a good reminder that being smart about theory is not at all the same as being smart about practice.
posted by LastOfHisKind at 6:24 PM on May 22, 2016 [4 favorites]


On a similar note to Across the pale parabola of joy's links (great username), you can read the second half of the two-volume, 300-page tome The acute radiation syndrome: A study of ten cases and a review of the problem online if you, like me, are terrible and want to hear about the medical details. (Case 3 is Slotin; Case 1 is Harry Daghlian), plus a follow-up from the 70s on survivors of the accident, plus the original painstaking calculation of dosages.

There's something weirdly sad and poignant about the investigation of a workplace accident itself being Important Original Science.
posted by Krom Tatman at 6:30 PM on May 22, 2016 [12 favorites]


Unless I'm mistaken, the 1999 Tokai incident in Japan did not involve a reactor (i.e., this wasn't anywhere near a place controlled fission was supposed to occur) but happened at a fuel processing facility owned by a mining company.
posted by XMLicious at 6:40 PM on May 22, 2016 [1 favorite]


From the Wikipedia article:

"Under Slotin's unapproved protocol, the only thing preventing this was the blade of a standard straight screwdriver, manipulated by the scientist's other hand. Slotin, who was given to bravado, became the local expert, performing the test on almost a dozen occasions, often in his trademark blue jeans and cowboy boots, in front of a roomful of observers."
posted by the Real Dan at 6:57 PM on May 22, 2016 [4 favorites]


For those interested in this stuff, the author of this piece has a fantastic blog.
posted by firechicago at 7:03 PM on May 22, 2016 [4 favorites]


I'm also surprised that Alex doesn't mention a ghoulish little detail that (as far as I know) he was the first to discover and publish: the demon core was the third core.

The Manhattan Project cast three plutonium cores during WWII. One was used in the Trinity test, and two were prepared for use in bombs. The core that killed Harry Daghlian and Louis Slotin was the last of those cores, which was ready just a few days too late to be dropped on a Japanese city (probably Kokura, weather permitting).
posted by firechicago at 7:16 PM on May 22, 2016 [6 favorites]


Four of the fatalities were just bad luck, involving a group of janitors who shared muscatel wine that was laced with antifreeze.

Some kind of suicide pact?
posted by dilaudid at 7:17 PM on May 22, 2016


This perfectly illustrates the difference between knowing something and believing it.

You don't call a procedure "tickling the dragon's tail" unless you full well know that eventually you're going to end up waking a supernatural force that will melt your face and make you very dead.

But you sure as heck don't actually do such a procedure unless you somehow believe it won't.
posted by Zalzidrax at 7:22 PM on May 22, 2016 [17 favorites]


Some kind of suicide pact?

Methanol (Methyl Alcohol) was a common form of antifreeze in the first half of the 20th century. Perhaps in an effort to fortify the muscatel someone added the wrong type of hootch.
posted by Zedcaster at 7:24 PM on May 22, 2016 [2 favorites]


The government knew that radiation would slowly and painfully kill people, and yet, as the article mentions, they were fully prepared to keep testing them on the people of the Marshall islands. Even after we saw the pictures of Hiroshima, we kept building them. Even after the meltdowns and the deadzones, we still keep building them. Our president has a Nobel peace prize, and he turned around and built more of them than the Bushes combined. There seems to be nothing so horrific that we will not keep building them.
posted by SecretAgentSockpuppet at 7:28 PM on May 22, 2016 [10 favorites]


Unless I'm mistaken, the 1999 Tokai incident in Japan did not involve a reactor (i.e., this wasn't anywhere near a place controlled fission was supposed to occur) but happened at a fuel processing facility owned by a mining company.

Yes and no: Tokaimura and the surrounding region Hitachi in Ibaraki Prefecture, just to the northeast of Tokyo, is the heartland of Japan's nuclear industry.

The workers may have been employed by Sumitomo Metals, but as part of a conglomerate in this case the company was assisting with creating nuclear fuel for the Joyo experimental breeder reactor, which was operated by state-owned Japan Nuclear Fuels (they changed names a few times; but in Tsuruga, where the entity operated the Tsuruga reactor, it's know as Nihon Genden). The Joyo breeder reactor is located at the large nationally-owned nuclear complex in Oarai, just south of Tokaimura.

So anyway, it wasn't at a reactor per se, but the reactor was close by. And the the nuclear core we're talking about in Los Alamos was absolutely nowhere near a nuclear reactor or a nuclear bomb.

Note: I was living in Omika, across the river from Tokai, during the fire at the reprocessing plant in 1997, and I have lived in 2 other nuclear town, Shika and Tsuruga) during my 20+ years in Japan.
posted by My Dad at 7:46 PM on May 22, 2016 [4 favorites]


Oh god I've seen pictures of this in a book of declassified photos from the Manhattan project. They took photos of his hand periodically throughout the what 72 hours he survived after this...it...well, it melted. D:
posted by sexyrobot at 8:24 PM on May 22, 2016 [3 favorites]


You know, I've heard account's of Slotkin's death a bunch of a times, but I've never had it actually explained what useful science was supposed to come out of this dumbass 'experiment'.
posted by tavella at 8:28 PM on May 22, 2016 [4 favorites]


Shouldn't I use my screwdrivers only for driving screws, one might ask, and not for, say, keeping this plutonium assembly from going critical?


At least he didn't use a wrench as a hammer...
posted by TheWhiteSkull at 8:41 PM on May 22, 2016 [3 favorites]


There was an incident in Austria back in the 1980s where people were sickened and died from wine that had been laced with diethylene glycol. It tastes sweet, apparently, and was added to crappy wine to make it sellable. This may be the same thing that happened with that muscatel.
posted by Blueeyed at 9:10 PM on May 22, 2016 [2 favorites]


Our president has a Nobel peace prize, and he turned around and built more of them than the Bushes combined.

The U.S. nuclear arsenal has not increased in size during the Obama presidency, and Obama canceled Bush-era plans to expand the nuclear arsenal. Obama did invest quite a bit in modernizing the U.S. nuclear arsenal, which from everything I've read was badly needed in order to reduce the risk of accidents.

I am curious to hear your source for the claim that Obama built more nuclear weapons than the Bushes combined. (It's also a bit of an odd timeframe for comparison since the U.S. has been reducing its nuclear arsenal since the fall of the Soviet Union, and the W. Bush administration deserves some credit for managing a significant chunk of that reduction -- one of the few accomplishments that administration does deserve credit for.)
posted by biogeo at 9:19 PM on May 22, 2016 [48 favorites]


I learned about this guy in a college physics class. I couldn't believe that someone could be that smart and yet that stupid at the same time. When I saw the movie, I jumped up in my seat, because I was the only one of my friends that knew what was about to happen.
posted by Cool Papa Bell at 9:35 PM on May 22, 2016


biogeo, the source is probably this recent FPP of an article by John Pilger, which does not, itself, cite a source.
posted by anastasiav at 9:41 PM on May 22, 2016 [4 favorites]


Oh right. If so, that article was filled with enough obvious falsehoods (I loved that even the thing about there being no birds was wrong) that a source with more respect for the truth would be helpful.
posted by biogeo at 10:03 PM on May 22, 2016


I suspect that if a smart person doesn't realize they can be so stupid then they assume that what they're doing is not that stupid.
posted by wotsac at 10:04 PM on May 22, 2016 [1 favorite]


But only Slotin and his co-worker Harry Daghlian, Jr., succumbed to the special hazards of the Manhattan Project. Three months to the day before Slotin’s accident, Daghlian had been working with the very same plutonium core, performing a different criticality experiment that used tungsten-carbide blocks instead of the beryllium tamper. He dropped one of the blocks, and the core briefly went critical. Daghlian took nearly a month to die.

After Slotin’s botched demonstration, Los Alamos halted all further criticality work. It was always known to be dangerous—Enrico Fermi himself had warned Slotin that he would be “dead within a year” if he continued ... [emphasis added]
There's little doubt in my mind that the first accident gave rise to the second.

Slotin performed his criticality experiment barely two months after his coworker Daghlian died from a very similar criticality experiment with the same core.

There is no way Slotin was not pre-occupied with Daghilan's blunder and subsequent death in the days leading up to his own experiment, and that he wasn't telling himself something to the effect of 'for the love God just don't drop the damper!' with Fermi's words ringing in his ears as he performed it -- and then he did, not of course, but predictably with an unacceptably high probability.

The failure here was that whoever had overall responsibility for these experiments above Slotin's level allowed this to take place at all.
posted by jamjam at 10:25 PM on May 22, 2016 [1 favorite]




Shouldn't I use my screwdrivers only for driving screws, one might ask, and not for, say, keeping this plutonium assembly from going critical?

Similarly, I should probably stop hammering nails with this cadmium control rod.
posted by justsomebodythatyouusedtoknow at 12:49 AM on May 23, 2016 [15 favorites]


the days leading up to his own experiment

That's what I mean! People keep calling it an "experiment", but what new knowledge was supposed to be learned from holding two sub-critical masses that you knew added up to a critical mass apart with a screwdriver? It seems like it was a stunt rather than science.
posted by tavella at 1:05 AM on May 23, 2016 [5 favorites]


LastOfHisKind: "This is a good reminder that being smart about theory is not at all the same as being smart about practice."
This incident reads to me more like the predictable outcome of macho/cowboy attitudes, not a case of a confused professor.
biogeo: "Obama did invest quite a bit in modernizing the U.S. nuclear arsenal, which from everything I've read was badly needed in order to reduce the risk of accidents."
Yup. If you're under any impression that the US stockpile of nuclear weapons was well-managed, do yourself a favour and read Command and Control: Nuclear Weapons, the Damascus Accident, and the Illusion of Safety. It'll give you a new-found appreciation of having survived the Cold War.
posted by brokkr at 1:17 AM on May 23, 2016 [11 favorites]


It'll give you a new-found appreciation of having survived the Cold War.

I mean, unless or until one's life is ended in some other fashion, I wouldn't necessarily assume one has.
posted by running order squabble fest at 6:13 AM on May 23, 2016 [2 favorites]


Shouldn't I use my screwdrivers only for driving screws, one might ask, and not for, say, keeping this plutonium assembly from going

You say screwdriver, I say plutonium assembly lever.
posted by museum of fire ants at 6:17 AM on May 23, 2016 [7 favorites]


Another Canadian connection here. The uranium for the Manhattan project was transported by Dene (pronounced "den-ay") workers:

At the dawn of the nuclear age, Paul Baton and more than 30 Dene hunters and trappers innocently called uranium "the money rock."

Paid $3 a day by their white employers, the Dene hauled and ferried burlap sacks of the grimy ore from the world's first uranium mine at Port Radium, across the Northwest Territories to Fort McMurray.

Since then, at least 14 Dene who worked at the mine between 1942 and 1960 have died of lung, colon and kidney cancers, according to documents obtained through the N.W.T. Cancer Registry.


Their deaths took longer to play out than Slotin's - and did so in obscurity:

Victor Dolphus' arm came off when he tried to start an outboard motor. Dolphus, who had worked at the mine site for years, needed a contraption to hold up his neck before the cancer finished him. Joe Kenny, a boat pilot, died of colon cancer. His son, Napoleon, a deck hand, died of stomach cancer. And so on.
posted by mandolin conspiracy at 6:22 AM on May 23, 2016 [15 favorites]


Command and Control is indeed well worth a read and also utterly terrifying.
posted by Artw at 6:23 AM on May 23, 2016


Would echo the recommendations for Command and Control.

Would not necessarily recommend reading it back-to-back with Voices from Chernobyl (also fantastic) just because your local library filled your holds for them at the same time. YMMV.
posted by mandolin conspiracy at 6:49 AM on May 23, 2016 [4 favorites]


Command and Control is one of the more sobering books I've read. It makes a good case that the greater threat during the cold war was not nuclear war but a city getting vaporized because some fool didn't follow a checklist.
posted by nathan_teske at 7:51 AM on May 23, 2016 [4 favorites]


My husband keeps trying to get me to read Command and Control, and I keep saying "Look, dude, I have to get to sleep at night and I just stopped having nuclear war nightmares a few years ago, so no. Also, stop trying to tell me about what you read."

This story doesn't do that to me because it was mere human stupidity, not mere human stupidity + massive stockpile of world-ending bombs.
posted by emjaybee at 8:14 AM on May 23, 2016 [2 favorites]




The point of the experiment was to quantify the actual purity of the core. They knew crudely that they had a mass that could be made critical but the exact composition was difficult to determine. One method though goes something like this...

Given that we have a very precision machined and measured core and precision machined and measured moderator if we bring the moderator down over the core while measuring the distance and note the when it just barely trips into criticality (as determined by a radiation detector) we can mathematically work out the exact composition of the core.
posted by dustsquid at 10:26 AM on May 23, 2016 [6 favorites]


This has a pretty good explanation of the goals of the criticality experiments. Basically, a core like the ones in the experiment gives off neutrons at a certain rate; occasionally, a neutron will stimulate another neutron in the core to be emitted or will be reflected back in, but on net, there's more neutrons being put out than are reacting inside the core. If you reflect some of the neutrons back in, there's more neutron-atom reactions happening, which in turn increases the whole output of neutrons (and the rate of fissions caused by neutrons hitting radioactive nuclei). At a certain point, there's enough neutrons hitting the core, and giving off neutrons that hit the core again, and you have a chain reaction.

The rate at which the neutron flux increases as you approach criticality follows a curve, and by plotting points in the subcritical portion of the curve (by measuring how the flux increases), you can extrapolate what the critical mass will be, which has implications for how to build a bomb that explodes right when you want it to.
posted by Krom Tatman at 10:44 AM on May 23, 2016 [3 favorites]


Thanks! So at least there was some point, though it still seems as if they would have gotten more accurate and safer results by building a mechanism that would remove a wedge in a carefully controlled manner, and in a lab rather than a room full of people. So I'm still voting dumbass stunt.
posted by tavella at 12:12 PM on May 23, 2016 [1 favorite]


the days leading up to his own experiment

That's what I mean! People keep calling it an "experiment", but what new knowledge was supposed to be learned from holding two sub-critical masses that you knew added up to a critical mass apart with a screwdriver? It seems like it was a stunt rather than science.
Not to put too fine a point on it, but neither Daghilan's nor Slotin's experiment involved two subcritical masses that added up to a critical mass; both used a single core that was subcritical as it stood and brought a neutron reflector up next to it to push it closer to criticality, tungsten carbide in Daghilan's, and beryllium in Slotin's.

A heavy tungsten carbide block slipped out of Daghilan's hand and fell down on to the core, and the presumably much lighter beryllium cap slipped off Slotin's screwdriver and fell down onto the core.

Krom Tatman's link contradicts the article linked in the post on at least a couple of points in saying that Daghilan's accident took place a year before Slotin's rather than three months, and that the the block that fell out of Daghilan's hand was uranium rather than tungsten carbide.

The demon core was plutonium, and plutonium, as I understand it, was in particularly short supply at that point in time, so it seems likely to me that the immediate goal of both experiments was to explore ways of getting more bombs and/or more powerful bombs out of that limited supply.

Checking the link in the FPP just now, I notice that the stated date of Daghilan's experiment has been corrected since yesterday:
Harry Daghlian, Jr., succumbed to the special hazards of the Manhattan Project. Nine months to the day before Slotin’s accident, Daghlian had been working with the very same plutonium core, performing a different criticality experiment that used tungsten-carbide blocks instead of the beryllium tamper.*
...
*Correction: An earlier version of this article misstated the timing of Daghlian’s accident
posted by jamjam at 12:56 PM on May 23, 2016 [4 favorites]


...and I mis-spelled 'Daghlian' all the way through.
posted by jamjam at 1:07 PM on May 23, 2016


I think Slotin's death was the inspiration for the excellent short story Heat of Fusion by John M. Ford. (That, and the fact that Ford was hospitalised after a kidney transplant while writing it.) It's a great story, written in the form of first-person diary entries, and has always haunted me.
posted by Pallas Athena at 3:19 PM on May 23, 2016


This is a good occasion to ask yourself: am I including "now wedge a screwdriver in there" as part of some important work that I do? Shouldn't I use my screwdrivers only for driving screws, one might ask, and not for, say, keeping this plutonium assembly from going critical?

just be super careful, sheesh.. it's just a core, not brain surgery..
posted by rainy at 8:37 PM on May 23, 2016 [1 favorite]


This story is one of those great case studies in laboratory safety and happens to be the source of one of the most important laboratory safety rule I know. Specifically: do not perform plutonium criticality experiments without adequate shielding. This rule has served me well for many years.
posted by fremen at 9:48 PM on May 23, 2016 [5 favorites]


Atomic Accidents is another great book to read with lots of criticality accidents (and others) and a detailed breakdown of how they happened. Totally fascinating and also totally bone-chillingly scary.
posted by fiercecupcake at 1:59 PM on May 24, 2016 [1 favorite]


Oh, and in case anyone was wondering what would have happened if Slotin just let the criticality keep on criticalin', check out this Reddit post.
posted by fiercecupcake at 8:39 AM on May 25, 2016 [2 favorites]


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