Reply
 
Thread Tools Display Modes
  #1  
Old 05-15-2019, 04:38 PM
Wesley Clark is offline
2018 Midterm Prediction Winner
 
Join Date: Aug 2003
Posts: 21,693

How does radiation make inanimate objects around it radioactive


I watched the first episode of Chernobyl last night and there were several parts where someone would touch an item that was exposed to radiation, and that would make them sick or injured.

So how does that work? Wouldn't the subatomic particles and gamma rays just hit other inanimate objects, and that is it? Why would those other objects become radioactive? Like if you put a metal rod next to a radioactive item, why would the rod become radioactive? The atoms that are emitting radioactive particles are still in the radioactive item, not in the metal rod. Or does an atomic explosion cause these radioactive atoms to shower everything around them, and that is why other items because radioactive?

Also does radiation cause instant burns like in the show? I thought radiation damaged your DNA which is bad, but wouldn't cause symptoms for a few hours or days. Shouldn't a UV burn take several hours to start showing symptoms after it starts?
__________________
Sometimes I doubt your commitment to sparkle motion

Last edited by Wesley Clark; 05-15-2019 at 04:38 PM.
  #2  
Old 05-15-2019, 04:53 PM
beowulff's Avatar
beowulff is offline
Member
 
Join Date: May 2001
Location: Scottsdale, more-or-less
Posts: 16,437
https://en.m.wikipedia.org/wiki/Neutron_activation
  #3  
Old 05-15-2019, 04:54 PM
engineer_comp_geek's Avatar
engineer_comp_geek is offline
Robot Mod in Beta Testing
Moderator
 
Join Date: Mar 2001
Location: Pennsylvania
Posts: 23,847
Something like a gamma ray can knock a neutron out of an atom. That free neutron then slams into another atom and gets absorbed, causing that atom to become unstable and radioactive. The same sort of thing can happen with other subatomic particles as well.

As for how quickly symptoms of radiation exposure appear, that depends a lot on the type of radiation and the dosage level. At very high exposure levels, it is possible for all kinds of symptoms to appear very quickly.
  #4  
Old 05-15-2019, 05:00 PM
DPRK is offline
Guest
 
Join Date: May 2016
Posts: 3,033
Also, an uncontained explosion like at Chernobyl sprays highly radioactive atoms all over the place; it's not like all you have to worry about are a few stray neutrons or gamma rays.

Last edited by DPRK; 05-15-2019 at 05:01 PM.
  #5  
Old 05-15-2019, 05:22 PM
DPRK is offline
Guest
 
Join Date: May 2016
Posts: 3,033
ETA the greater the dose, the faster beta burns begin to manifest. If you pick up a "nuclear tan" without even a delay of a couple of hours, well, I wouldn't start making long-term plans.
  #6  
Old 05-15-2019, 05:28 PM
Northern Piper is offline
Charter Member
 
Join Date: Jun 1999
Location: The snow is gone. For now
Posts: 28,844
After Slotkin was exposed to high radiation levels in the "demon core #2" accident, he started throwing up within a few minutes, a sign of serious radiation poisoning.
__________________
"I don't like to make plans for the day. If I do, that's when words like 'premeditated' start getting thrown around in the courtroom."
  #7  
Old 05-15-2019, 06:23 PM
Darren Garrison's Avatar
Darren Garrison is offline
Guest
 
Join Date: Oct 2016
Posts: 10,379
Subatomic particles hitting inanimate objects and making them radioactive is the whole way that nuclear reactors and nuclear bombs work.
  #8  
Old 05-15-2019, 06:29 PM
Chronos's Avatar
Chronos is offline
Charter Member
Moderator
 
Join Date: Jan 2000
Location: The Land of Cleves
Posts: 82,695
Quote:
Quoth engineer_comp_geek:

Something like a gamma ray can knock a neutron out of an atom.
While this is in principle possible, for an extremely high-energy gamma ray, it's very rare. You're much more likely to get transmutation from alpha particles, and more likely yet from neutrons.

And you can also get contamination, where bits of the original substance (usually in the form of dust) get on the new item. This can be addressed by thorough washing, if it's the sort of thing that can be thoroughly washed.
  #9  
Old 05-15-2019, 08:14 PM
Gray Ghost is offline
Guest
 
Join Date: Apr 2008
Posts: 3,823
The wiki for radiation burns is rather detailed, and suggests that the producers of Chernobyl are taking a bit of dramatic license with the rapidity of the onset of exposure symptoms. https://en.m.wikipedia.org/wiki/Radiation_burn

Not much though. Erythema, from that link, is not stated to be immediate with doses below 30 Gy. Which might be survivable, if an extremity or a tightly focused area was the only thing subjected to the dose, even if 36 Gy is easily 100 percent fatal as a whole body prompt dose. The poster aruqvan, in another thread discussing the show, mentioned her own radiation therapy, with a cumulative dose of, IIRC, 36 Gy.

Not all radiation, even of the same general type, is equal. I can imagine that, e.g., very high energy beta might lead to more immediate erythema than lesser energy particles.
  #10  
Old 05-15-2019, 09:38 PM
Wesley Clark is offline
2018 Midterm Prediction Winner
 
Join Date: Aug 2003
Posts: 21,693
Quote:
Originally Posted by Darren Garrison View Post
Subatomic particles hitting inanimate objects and making them radioactive is the whole way that nuclear reactors and nuclear bombs work.
No, those subatomic particles are hitting highly fissile material, setting off a chain reaction. Most atoms are not fissile, so a neutron hitting them shouldn't set off a chain reaction.

I didn't know about Neutron activation as posted by Beowulff but that explains it. I didn't know so many different materials could become radioactive just by being exposed to radiation. I thought it had to be a very unstable atom for that to happen, but apparently not.
__________________
Sometimes I doubt your commitment to sparkle motion
  #11  
Old 05-16-2019, 01:09 PM
ftg's Avatar
ftg is offline
Guest
 
Join Date: Feb 2001
Location: Not the PNW :-(
Posts: 18,990
When I was in 2nd year Physics, some of us got to do more advanced labs. One I remember was irradiating silver foils with neutrons and then measuring the decay to find the half-lives of the two main isotopes produced. Much like this.

Note that we were turning a tiny bit of silver into cadmium. So that was worthwhile.

Neutrons are really good for mucking up nuclei since they can so easily get into range unlike protons. But neutron sources are not as easily created and controlled as protons. For those you just ionize some hydrogen and run them thru a magnetic field. Something you can do in your garage. Luckily this means there aren't a bunch of folk creating radioactive sources in their spare time.
  #12  
Old 05-16-2019, 03:34 PM
Darren Garrison's Avatar
Darren Garrison is offline
Guest
 
Join Date: Oct 2016
Posts: 10,379
Quote:
Originally Posted by Wesley Clark View Post
No, those subatomic particles are hitting highly fissile material, setting off a chain reaction. Most atoms are not fissile, so a neutron hitting them shouldn't set off a chain reaction.

In a nuclear reactor, neutrons collide with atoms and cause them to undergo nuclear decay. In neutron activation, on the other hand, neutrons collide with atoms and cause them to undergo nuclear decay.
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 04:44 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.

Send questions for Cecil Adams to: cecil@straightdope.com

Send comments about this website to: webmaster@straightdope.com

Terms of Use / Privacy Policy

Advertise on the Straight Dope!
(Your direct line to thousands of the smartest, hippest people on the planet, plus a few total dipsticks.)

Copyright 2018 STM Reader, LLC.

 
Copyright © 2017