
Demon Core - agarttha
https://en.wikipedia.org/wiki/Demon_core
======
vilhelm_s
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?

~~~
jefftk
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
[https://imgur.com/a/5Vc487x](https://imgur.com/a/5Vc487x)

~~~
sl1ck731
This is just SnapOn's attempt to get you to buy a 50$ 12" prybar. Also to stop
you from sending your screwdrivers back on the truck every week.

But who cares, they're replaced for free and delivered :)

~~~
thrower123
Or buy four or five Pittsburgh ones from Harbor Freight.

Those have a lifetime warranty now too.

I would love to have SnapOn stuff, if I were made of money or found it second-
hand, but it's just stupid expensive new, especially for stuff that tends to
get abused.

~~~
sl1ck731
Some of the Harbor Freight stuff is great. For wrenches and ratchets that get
pushed to the limit though I'll exclusively use one of the more pricey brands
just out of fear of slamming my knuckles after a tool snaps. Its one of my
biggest fears working on anything even after having it happen with minimal
damage enough times. For everything else I'll use whatever is closest.

------
eprparadox
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:Sloti...](https://en.wikipedia.org/wiki/Louis_Slotin#/media/File:Slotin_criticality_map.png)

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:Sloti...](https://en.wikipedia.org/wiki/Louis_Slotin#/media/File:Slotin_criticality_drawing.jpg)

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=zE...](https://open.spotify.com/artist/37U37SYaXf1varqMgmpHkc?si=zEBqJ0GqTG6jOEqb9tI-
Nw)

------
Isxida
There's a guy who is making a cartoon about the demon core.

[https://youtu.be/Eyl3WQCttQ8](https://youtu.be/Eyl3WQCttQ8)

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

~~~
errantspark
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.

~~~
bsder
> soldering on equipment plugged into mains

o_O!!!!!!!

I've cut a _LOT_ of corners, but that one is just insane...

~~~
protomyth
Someone hooked the washer and dryer into the mains at my Grandma’s house. It
was interesting seeing my Dad go from confused to realization to angry without
having caused the transition. Getting that fixed was an exercise in careful.
As Dad is fond of saying “I’m amazed you thought of it and appalled you
actually did it.”

~~~
joefourier
Funnily enough that's a normal practice in the UK/Ireland. In all the places
I've lived, washer and dryer are plugged straight into a regular outlet
(sometimes with an extension cord if it can't be reached).

Makes me wonder, why not make a 110v washing machine and save the trouble of
having both 110v and 220v at home?

~~~
mikeash
Most (all?) washing machines are 120V. Electric dryers rarely are, because
they need a lot more power. I had a small washer/dryer combo unit years ago
that used 120V, and it took about four hours to dry a load that was about half
the size of a normal dryer’s capacity.

Running both voltages into a house isn’t much of a burden. Residential
electricity in the US is two-phase. A 120V circuit pulls from one phase, with
the various circuits in your house divided between them to even out the load.
A 240V circuit just connects to both phases.

------
vermontdevil
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
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.

------
dang
Related from 2016:
[https://news.ycombinator.com/item?id=11749742](https://news.ycombinator.com/item?id=11749742)

------
2bitencryption
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
> 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
>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
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)

------
yoctonaut
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.)

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tunnuz
Didn’t know this! Really interesting

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

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

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grlass
The authority on the subject:
[https://youtu.be/lJXwRdbbQ50](https://youtu.be/lJXwRdbbQ50)

~~~
AceJohnny2
Why "authority"?

