8 ms·

Demon Core

153 points by agarttha 7y ago

grlass 7y ago
The authority on the subject: https://youtu.be/lJXwRdbbQ50 https://youtu.be/lJXwRdbbQ50
- AceJohnny2 7y ago
  Why "authority"?
dang 7y ago
Related from 2016: https://news.ycombinator.com/item?id=11749742 https://news.ycombinator.com/item?id=11749742
tunnuz 7y ago
Didn’t know this! Really interesting
CodiePetersen 7y ago
Tickling the dragons tail seems very appropriate. I'd be sweating bullets manaually adjusting a nuke core with a screw driver.
- errantspark 7y ago
  Not to advocate risky behavior, but this doesn't surprise me at all. Experience increases the perception of safety at a rate faster than actual safety. Every place I've worked where you could put yourself, expensive equipment or customer satisfaction in danger to make something easier for yourself people would do it. Deploying straight to prod, doing surgery on live databases, soldering on equipment plugged into mains, servicing a UPS without disconnecting 48V worth of lead acid batteries (that was one HELL of an arc weld). The corners people will cut never cease to amaze me.
  - lucidstack 7y ago
    Good old normalization of deviance: https://www.ncbi.nlm.nih.gov/m/pubmed/25742063/ https://www.ncbi.nlm.nih.gov/m/pubmed/25742063/
  - MaysonL 7y ago
    This is why power paper cutters have two widely separated on buttons.
  - PhasmaFelis 7y ago
    > Experience increases the perception of safety at a rate faster than actual safety. I learned to drive nine months ago, and I've been watching myself do this every time I get on the highway in the past few months. Even knowing that I'm doing it, it's hard to avoid.
    - Gibbon1 7y ago
      I learned to drive 40 years ago. Watching yourself drive and noticing situations where you're taking unneeded risks is what separates good drivers from mediocre ones. Never assume you can't do better.
  - bsder 7y ago
    > soldering on equipment plugged into mains o_O!!!!!!! I've cut a LOT of corners, but that one is just insane...
    - hinkley 7y ago
      "But this is the ground wire so it's okay". Hint: Lots of people have daisy chained outlets backward, and lots of AC circuits still work with the wiring reversed. Pretty sure we found one where they had reversed them twice, so black was hot at the end of the circuit but not in the middle.
      - xyzzy_plugh 7y ago
        I have no idea why I never considered this possibility. That's terrifying.
- shdh 7y ago
  Hollywood portrayal: https://www.youtube.com/watch?v=hh89h8FxNhQ https://www.youtube.com/watch?v=hh89h8FxNhQ
Isxida 7y ago
There's a guy who is making a cartoon about the demon core. https://youtu.be/Eyl3WQCttQ8 https://youtu.be/Eyl3WQCttQ8
- deleted 7y ago
  [deleted]
vilhelm_s 7y ago
I like this comment from Metafilter (https://www.metafilter.com/159810/Blue-flash#6535495 https://www.metafilter.com/159810/Blue-flash#6535495): > 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?
- deleted 7y ago
  [deleted]
- jefftk 7y ago
  There are lots of reasonable uses for flathead screwdrivers other than driving screws, though! Random examples: * Many clips (dryer faceplate, window sash, ...) are designed to be pried open with a screwdriver. * When repairing a popped drywall nail, a screwdriver is a good tool for removing the joint compound under the nail. * When you buy a lock it usually comes with a rounded faceplate. To swap the faceplate, they'll tell you to use a screwdriver to pry it off. A flathead screwdriver is a good tool for general light prying, not just for putting in slotted screws. This heuristic has a lot of false positives.
  - mplewis 7y ago
    https://imgur.com/a/5Vc487x https://imgur.com/a/5Vc487x
    - jefftk 7y ago
      Prying with a flathead screwdriver is totally standard. Examples from manufacturer instructions: * "Use a small flathead screwdriver to pry wire connectors off." http://www.crystalcoolers.com/CMIL/ServiceManual/EverestElite/110V_POU/HotTankReplacement%20.aspx http://www.crystalcoolers.com/CMIL/ServiceManual/EverestElit... * "Use a flathead screwdriver to GENTLY push the wire harness from the board." https://www.carlisleft.com/library/SI06031si.pdf https://www.carlisleft.com/library/SI06031si.pdf * "Carefully remove the airbag plastic logo. This plastic piece is set deep into the door so be sure to pry it with some force by inserting a small flathead screw driver just under the plastic piece and pushing it out." https://bimmian.com/content/pdfs/CMC46.pdf https://bimmian.com/content/pdfs/CMC46.pdf * "Use your flathead screwdriver to release the two clips on each side." https://lib.americanmuscle.com/files/contentgenerator/deatschwerks-340lph-fuel-pump-9904-cust-install-393283.html/393283-cust.pdf https://lib.americanmuscle.com/files/contentgenerator/deatsc... A prybar is for when you need a lot more force.
yoctonaut 7y ago
Alex Wellerstein, author of the NYer article, has a bit more info on his blog (http://blog.nuclearsecrecy.com/2016/05/23/the-blue-flash/ http://blog.nuclearsecrecy.com/2016/05/23/the-blue-flash/), including an answer to the question of what happened to the core. (It was melted down into the overall plutonium stockpile, apparently.)
2bitencryption 7y ago
I'm wondering, even if everything had gone right and the dome had not been dropped to cause the core to go critical -- surely being in close contact with even a non-critical nuclear weapon core is not safe?? What's the amount of radiation that thing gave off simply from decay, in a non-critical state?
- ceejayoz 7y ago
  > What's the amount of radiation that thing gave off simply from decay, in a non-critical state? Not much. U-235 has a 700M year half-life. Pu-239's is 24,000 years. You're more at risk from ingesting/inhaling bits of it.
  - errantspark 7y ago
    >You're more at risk from ingesting/inhaling bits of it. This is the vaaaast majority of the risk profile for radioactive anything. The half life doesn't really tell you the whole story, Pu-239 mostly decays into alpha particles which is what makes it "safe", it's still not good for you, and very bad if ingested, but externally alpha radiation doesn't really penetrate deep enough into the body to be a big problem.
    - muthas 7y ago
      To put it another way - from an "immediate risk" point of view, the largest danger from critical-capable amount of fissile material is the prompt radiation emitted during a criticality: the pulse of neutrons, gamma and x-rays thrown off during that period the unit is sustaining a chain reaction. For relatively brief power excursions like this one (which Slotin himself stopped by removing the reflector), the prompt burst was well over a lethal level but the radiation dose-rate from fission product decay even a tiny time later would not be immediately hazardous. For those looking to learn more, Los Alamos has a great writeup of every publicly-known incident (in the US, USSR, and elsewhere) that details just how many times similar incidents happened: https://www.orau.org/ptp/Library/accidents/la-13638.pdf https://www.orau.org/ptp/Library/accidents/la-13638.pdf
- 7y ago
vermontdevil 7y ago
The scene is fictionalized in the movie Fat Man and Little Boy with John Cusack performing the role of Slotin under a different name. https://en.wikipedia.org/wiki/Fat_Man_and_Little_Boy https://en.wikipedia.org/wiki/Fat_Man_and_Little_Boy
- Vaslo 7y ago
  Came here to say this. At the time I saw this in the early 90s, it really disturbed me-an awful way to go for such a mundane act.
Hackbraten 7y ago
Before I clicked, I was convinced the article was going to be about some GLaDOS core that I’ve forgotten.
draw_down 7y ago
Terrible, just terrible, that a device like this would hurt or even kill people.
eprparadox 7y ago
i was fascinated with the criticality accident that claimed Slotin's life when i first learned about it. in particular, there was a schematic made up after the accident estimating everyone's distance to the apparatus and how much radiation they may have been exposed to: https://en.wikipedia.org/wiki/Louis_Slotin#/media/File:Slotin_criticality_map.png https://en.wikipedia.org/wiki/Louis_Slotin#/media/File:Sloti... there was a second sketch made from that drawing which i also found fascinating. it doesn't add any additional information or analytical ability, but is just a sort of interesting and slightly dark translation of a rote schematic diagram into an artistic rendering of the event: https://en.wikipedia.org/wiki/Louis_Slotin#/media/File:Slotin_criticality_drawing.jpg https://en.wikipedia.org/wiki/Louis_Slotin#/media/File:Sloti... I searched around for awhile trying to find the purpose and/or author of that second sketch but to no avail. however i did use it as the cover for an EP i released. please enjoy! https://open.spotify.com/artist/37U37SYaXf1varqMgmpHkc?si=zEBqJ0GqTG6jOEqb9tI-Nw https://open.spotify.com/artist/37U37SYaXf1varqMgmpHkc?si=zE...
earthboundkid 7y ago
How ironic, that a bomb core would kill. Truly,

Demon Core

153 points by agarttha 7y ago

grlass 7y ago

The authority on the subject: https://youtu.be/lJXwRdbbQ50 https://youtu.be/lJXwRdbbQ50

AceJohnny2 7y ago
Why "authority"?

dang 7y ago

Related from 2016: https://news.ycombinator.com/item?id=11749742 https://news.ycombinator.com/item?id=11749742

tunnuz 7y ago

Didn’t know this! Really interesting

CodiePetersen 7y ago

Tickling the dragons tail seems very appropriate. I'd be sweating bullets manaually adjusting a nuke core with a screw driver.

errantspark 7y ago
Not to advocate risky behavior, but this doesn't surprise me at all. Experience increases the perception of safety at a rate faster than actual safety. Every place I've worked where you could put yourself, expensive equipment or customer satisfaction in danger to make something easier for yourself people would do it. Deploying straight to prod, doing surgery on live databases, soldering on equipment plugged into mains, servicing a UPS without disconnecting 48V worth of lead acid batteries (that was one HELL of an arc weld). The corners people will cut never cease to amaze me.
- lucidstack 7y ago
  Good old normalization of deviance: https://www.ncbi.nlm.nih.gov/m/pubmed/25742063/ https://www.ncbi.nlm.nih.gov/m/pubmed/25742063/
- MaysonL 7y ago
  This is why power paper cutters have two widely separated on buttons.
- PhasmaFelis 7y ago
  > Experience increases the perception of safety at a rate faster than actual safety. I learned to drive nine months ago, and I've been watching myself do this every time I get on the highway in the past few months. Even knowing that I'm doing it, it's hard to avoid.
  - Gibbon1 7y ago
    I learned to drive 40 years ago. Watching yourself drive and noticing situations where you're taking unneeded risks is what separates good drivers from mediocre ones. Never assume you can't do better.
- bsder 7y ago
  > soldering on equipment plugged into mains o_O!!!!!!! I've cut a LOT of corners, but that one is just insane...
  - hinkley 7y ago
    "But this is the ground wire so it's okay". Hint: Lots of people have daisy chained outlets backward, and lots of AC circuits still work with the wiring reversed. Pretty sure we found one where they had reversed them twice, so black was hot at the end of the circuit but not in the middle.
    - xyzzy_plugh 7y ago
      I have no idea why I never considered this possibility. That's terrifying.
shdh 7y ago
Hollywood portrayal: https://www.youtube.com/watch?v=hh89h8FxNhQ https://www.youtube.com/watch?v=hh89h8FxNhQ

Isxida 7y ago

There's a guy who is making a cartoon about the demon core. https://youtu.be/Eyl3WQCttQ8 https://youtu.be/Eyl3WQCttQ8

deleted 7y ago
[deleted]

vilhelm_s 7y ago

I like this comment from Metafilter (https://www.metafilter.com/159810/Blue-flash#6535495 https://www.metafilter.com/159810/Blue-flash#6535495): > 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?

deleted 7y ago
[deleted]
jefftk 7y ago
There are lots of reasonable uses for flathead screwdrivers other than driving screws, though! Random examples: * Many clips (dryer faceplate, window sash, ...) are designed to be pried open with a screwdriver. * When repairing a popped drywall nail, a screwdriver is a good tool for removing the joint compound under the nail. * When you buy a lock it usually comes with a rounded faceplate. To swap the faceplate, they'll tell you to use a screwdriver to pry it off. A flathead screwdriver is a good tool for general light prying, not just for putting in slotted screws. This heuristic has a lot of false positives.
- mplewis 7y ago
  https://imgur.com/a/5Vc487x https://imgur.com/a/5Vc487x
  - jefftk 7y ago
    Prying with a flathead screwdriver is totally standard. Examples from manufacturer instructions: * "Use a small flathead screwdriver to pry wire connectors off." http://www.crystalcoolers.com/CMIL/ServiceManual/EverestElite/110V_POU/HotTankReplacement%20.aspx http://www.crystalcoolers.com/CMIL/ServiceManual/EverestElit... * "Use a flathead screwdriver to GENTLY push the wire harness from the board." https://www.carlisleft.com/library/SI06031si.pdf https://www.carlisleft.com/library/SI06031si.pdf * "Carefully remove the airbag plastic logo. This plastic piece is set deep into the door so be sure to pry it with some force by inserting a small flathead screw driver just under the plastic piece and pushing it out." https://bimmian.com/content/pdfs/CMC46.pdf https://bimmian.com/content/pdfs/CMC46.pdf * "Use your flathead screwdriver to release the two clips on each side." https://lib.americanmuscle.com/files/contentgenerator/deatschwerks-340lph-fuel-pump-9904-cust-install-393283.html/393283-cust.pdf https://lib.americanmuscle.com/files/contentgenerator/deatsc... A prybar is for when you need a lot more force.

yoctonaut 7y ago

Alex Wellerstein, author of the NYer article, has a bit more info on his blog (http://blog.nuclearsecrecy.com/2016/05/23/the-blue-flash/ http://blog.nuclearsecrecy.com/2016/05/23/the-blue-flash/), including an answer to the question of what happened to the core. (It was melted down into the overall plutonium stockpile, apparently.)

2bitencryption 7y ago

I'm wondering, even if everything had gone right and the dome had not been dropped to cause the core to go critical -- surely being in close contact with even a non-critical nuclear weapon core is not safe?? What's the amount of radiation that thing gave off simply from decay, in a non-critical state?

ceejayoz 7y ago
> What's the amount of radiation that thing gave off simply from decay, in a non-critical state? Not much. U-235 has a 700M year half-life. Pu-239's is 24,000 years. You're more at risk from ingesting/inhaling bits of it.
- errantspark 7y ago
  >You're more at risk from ingesting/inhaling bits of it. This is the vaaaast majority of the risk profile for radioactive anything. The half life doesn't really tell you the whole story, Pu-239 mostly decays into alpha particles which is what makes it "safe", it's still not good for you, and very bad if ingested, but externally alpha radiation doesn't really penetrate deep enough into the body to be a big problem.
  - muthas 7y ago
    To put it another way - from an "immediate risk" point of view, the largest danger from critical-capable amount of fissile material is the prompt radiation emitted during a criticality: the pulse of neutrons, gamma and x-rays thrown off during that period the unit is sustaining a chain reaction. For relatively brief power excursions like this one (which Slotin himself stopped by removing the reflector), the prompt burst was well over a lethal level but the radiation dose-rate from fission product decay even a tiny time later would not be immediately hazardous. For those looking to learn more, Los Alamos has a great writeup of every publicly-known incident (in the US, USSR, and elsewhere) that details just how many times similar incidents happened: https://www.orau.org/ptp/Library/accidents/la-13638.pdf https://www.orau.org/ptp/Library/accidents/la-13638.pdf
7y ago

vermontdevil 7y ago

The scene is fictionalized in the movie Fat Man and Little Boy with John Cusack performing the role of Slotin under a different name. https://en.wikipedia.org/wiki/Fat_Man_and_Little_Boy https://en.wikipedia.org/wiki/Fat_Man_and_Little_Boy

Vaslo 7y ago
Came here to say this. At the time I saw this in the early 90s, it really disturbed me-an awful way to go for such a mundane act.

Hackbraten 7y ago

Before I clicked, I was convinced the article was going to be about some GLaDOS core that I’ve forgotten.

draw_down 7y ago

Terrible, just terrible, that a device like this would hurt or even kill people.

eprparadox 7y ago

i was fascinated with the criticality accident that claimed Slotin's life when i first learned about it. in particular, there was a schematic made up after the accident estimating everyone's distance to the apparatus and how much radiation they may have been exposed to: https://en.wikipedia.org/wiki/Louis_Slotin#/media/File:Slotin_criticality_map.png https://en.wikipedia.org/wiki/Louis_Slotin#/media/File:Sloti... there was a second sketch made from that drawing which i also found fascinating. it doesn't add any additional information or analytical ability, but is just a sort of interesting and slightly dark translation of a rote schematic diagram into an artistic rendering of the event: https://en.wikipedia.org/wiki/Louis_Slotin#/media/File:Slotin_criticality_drawing.jpg https://en.wikipedia.org/wiki/Louis_Slotin#/media/File:Sloti... I searched around for awhile trying to find the purpose and/or author of that second sketch but to no avail. however i did use it as the cover for an EP i released. please enjoy! https://open.spotify.com/artist/37U37SYaXf1varqMgmpHkc?si=zEBqJ0GqTG6jOEqb9tI-Nw https://open.spotify.com/artist/37U37SYaXf1varqMgmpHkc?si=zE...

earthboundkid 7y ago

How ironic, that a bomb core would kill. Truly,