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Old 10-14-2021, 09:30 AM   #11
Fred Brackin
 
Join Date: Aug 2007
Default Re: GURPS effects of exposure to a nuclear fuel source

Quote:
Originally Posted by Michael Thayne View Post
For the kind of plot that's bouncing around in my head, maybe I should use a Strontium-90 RTG.ol.
I can't help you with Anthony's math but when I google Strontium-90 I get a beta decay with an energy of .5 MEV and then a 2,2 MEV beta particle from subsequent decay of a Yttrium byproduct.

Usually beta particles have so little pentration that you don't bother calculating their effects. Strontium is different because it mimics calcium and binds to bones producing bone cancer and leukemia...... eventually.

So in the probable time frame of your adventure the effects might be nothing with very serious long-term effects significiantly later..
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Old 10-14-2021, 10:32 AM   #12
Michael Thayne
 
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Default Re: GURPS effects of exposure to a nuclear fuel source

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Originally Posted by Fred Brackin View Post
I can't help you with Anthony's math but when I google Strontium-90 I get a beta decay with an energy of .5 MEV and then a 2,2 MEV beta particle from subsequent decay of a Yttrium byproduct.

Usually beta particles have so little pentration that you don't bother calculating their effects. Strontium is different because it mimics calcium and binds to bones producing bone cancer and leukemia...... eventually.

So in the probable time frame of your adventure the effects might be nothing with very serious long-term effects significiantly later..
Oh hmmm. I knew the penetration of beta particles wasn't great but I was thinking you might at least get skin cancer or something. So I guess the premise of this post was largely wrong and it really is just fission products (i.e. meltdown, fallout, and nuclear waste), not anything else, that kill you by proximity.
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Old 10-14-2021, 11:38 AM   #13
Celjabba
 
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Default Re: GURPS effects of exposure to a nuclear fuel source

Civilian radiation sources can and have killed by unshielded contact or proximity.
Such as the one used in medical devices, food chain irradiation or RTG.
Fuel rods, probably not, unless exposed to fluor based acids, and someone breath the fumes ? I think there was such a case at one time.

Some real life deadly accidents :

https://en.wikipedia.org/wiki/List_o...tion_accidents

Some of those match your descriptions, such as the ones on September 13, 1987, or December 2, 2001 (RTG)

Not to mention https://en.wikipedia.org/wiki/Demon_core
(weapon core that went supercritical by mishandling)

However, I am not sure how to calculate the Accumulated Dose for Gurps consequences.
I am on my phone, but I think there was information in either space or THS, I will check later.

Last edited by Celjabba; 10-14-2021 at 11:43 AM.
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Old 10-14-2021, 11:48 AM   #14
Anthony
 
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Location: Berkeley, CA
Default Re: GURPS effects of exposure to a nuclear fuel source

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Originally Posted by Michael Thayne View Post
Oh hmmm. I knew the penetration of beta particles wasn't great but I was thinking you might at least get skin cancer or something..
Penetration of beta in water or flesh is about 5mm per MeV, so unshielded Sr-90 is plenty able to produce localized radiation burns, though not the whole body doses the GURPS radiation rules assume.
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Old 10-14-2021, 04:09 PM   #15
johndallman
 
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Default Re: GURPS effects of exposure to a nuclear fuel source

I think what you want is someone being careless with food irradiation equipment. Gear that will sterilise bulk meat will do nasty things to living humans. The source it's easiest to be careless with is Cobalt-60, which produces lots of 1.17 and 1.48 MeV gamma rays, which have plenty of penetrating power.
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Old 10-14-2021, 04:24 PM   #16
Michael Thayne
 
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Default Re: GURPS effects of exposure to a nuclear fuel source

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Originally Posted by Celjabba View Post
Civilian radiation sources can and have killed by unshielded contact or proximity.
Such as the one used in medical devices, food chain irradiation or RTG.
Fuel rods, probably not, unless exposed to fluor based acids, and someone breath the fumes ? I think there was such a case at one time.

Some real life deadly accidents :

https://en.wikipedia.org/wiki/List_o...tion_accidents

Some of those match your descriptions, such as the ones on September 13, 1987, or December 2, 2001 (RTG)

Not to mention https://en.wikipedia.org/wiki/Demon_core
(weapon core that went supercritical by mishandling)

However, I am not sure how to calculate the Accumulated Dose for Gurps consequences.
I am on my phone, but I think there was information in either space or THS, I will check later.
If I understand the relevant science correctly, the Demon Core could in some ways have become more dangerous after the two incidents it was involved in, since briefly going critical would have produced some relatively long-lasting gamma-ray sources, possibly including cesium-137 (I say "possibly" because I'm not sure if plutonium fission does that, or just uranium). Also not sure how hot the thing would have gotten just sitting around.

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Originally Posted by johndallman View Post
I think what you want is someone being careless with food irradiation equipment. Gear that will sterilise bulk meat will do nasty things to living humans. The source it's easiest to be careless with is Cobalt-60, which produces lots of 1.17 and 1.48 MeV gamma rays, which have plenty of penetrating power.
Yeah—cobalt-60 is also used in medical equipment, and has been a source of nasty mishaps in the real world. Though it has a shorter half-life than many fairly dangerous isotopes—how long would it take for a hunk of cobalt-60 to become less dangerous than an equivalent mass of nuclear waste?

(Edit: I mean nuclear waste from a reactor—old cobalt-60 is of course another variety of nuclear waste.)

Last edited by Michael Thayne; 10-14-2021 at 04:30 PM.
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Old 10-18-2021, 12:16 PM   #17
cvannrederode
 
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Default Re: GURPS effects of exposure to a nuclear fuel source

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This page has a depression repetition on the theme of a worker at a food sterilization plant bypassing safety controls to clear a jam, getting irradiated, and lingering for months before dying.
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Old 10-18-2021, 03:03 PM   #18
Pursuivant
 
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Default Re: GURPS effects of exposure to a nuclear fuel source

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Originally Posted by Michael Thayne View Post
GURPS Disasters: Meltdown and Fallout goes into some detail about dramatic ways nuclear technology can do bad stuff to you. But what if there's no meltdown, no fallout, and instead you're just directly exposed to a nuclear fuel source—say because some idiot decided to dissect a nuclear bomb or radioisotope thermoelectric generator?
In such cases, the main risk to everyone involved is irradiated particulate matter, especially if it is an aerosol or finely ground dust which is easily suspended in air or water so it gets ingested or inhaled. While safety equipment is specifically designed to protect against such threats, there's always the risk of equipment failure or some other source of unprotected exposure.

If someone does inhale/ingest alpha or beta particles, or get them on their body or clothing, the race is on to get them decontaminated and on chelating drugs or otherwise remove as much radioactive material from their body as fast as possible. Hunting down potential victims in time treatment to do any good might be an adventure in itself.

Another possible avenue for exposure is objects or materials which have spent so much time in such close proximity to strong radiation emitters that they have become radioactive themselves. While they're unlikely to be so strongly radioactive that they cause burns or radiation illnesses, they have a strong potential to be long term cancer risks. The list of radiation accidents referenced above gives a good selection of such incidents.

A final risk from low level radiation is that it could be weaponized and scattered across a wide area. While the actual radiation risks are very low and likely to dissipate quickly, just the knowledge that the area is irradiated will get most normal people in a panic.

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Originally Posted by Michael Thayne View Post
Except alpha emitters often have much more dangerous isotopes in their decay chains. So how do you figure out the rads accumulated for, say, handling a fuel rod / pellet / etc. with no better protection than a pair of iron tongs?
I'd assess radiation exposure in terms of effective Rads per day or week. These might be relatively high for completely unprotected exposure where you might accidentally ingest alpha or beta particles to almost nil if you take suitable safety precautions.

Effects of long term low-level radiation exposure can take the form of penalties to Aging rolls, Susceptibility to certain cancers, the Sterility feature, and possibly the equivalent of 1-2 levels of Short Lifespan.

OSHA, CDC, DOE, etc. web sites have all sorts of info on these sorts of hazards.
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Old 10-18-2021, 03:16 PM   #19
Pursuivant
 
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Default Re: GURPS effects of exposure to a nuclear fuel source

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Originally Posted by Anthony View Post
Penetration of beta in water or flesh is about 5mm per MeV, so unshielded Sr-90 is plenty able to produce localized radiation burns, though not the whole body doses the GURPS radiation rules assume.
GURPS 3E had rules for localized radiation burns, but I'm not sure if they were ever ported over to GURPS 4E.

Summary of GURPS 3E Compendium 2 rules:

Divide "whole body dose" of ionizing radiation by % of body exposure to determine total Rads of exposure. (e.g., 1/15 for head or one limb).

The GM can also assess the equivalent of Burn damage to the radiated hit location, assessed over several months, with attendant risk of Infection.

Treat damage from massive or charged particles like Alpha particles as just slow-moving burn damage. Treat lighter uncharged particles as pro-rated whole body exposure as described above.
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