4 ms·

I'd be really happy if we could handle radioactive waste with the same level of concern we assign to things like arsenic, cadmium, mercury, or any of the other

by saulrh 9y ago

I'd be really happy if we could handle radioactive waste with the same level of concern we assign to things like arsenic, cadmium, mercury, or any of the other poisons we dump into open pits that'll kill you horribly and won't go away ever.

DuskStar 9y ago
I'm honestly not sure which direction you mean - should we be really careless with nuclear waste, like we are with heavy metals, or should we treat heavy metal waste with more care?
- saulrh 9y ago
  Both, meeting somewhere in the middle - nuclear waste is treated way too carefully, and non-nuclear heavy metal waste is treated rather too carelessly. Either way, the important point is for the level of care to be proportional to the actual danger, rather than determined entirely by whether it's called "radioactive" or not.
  - eru 9y ago
    Coal ash is even worse in its treatment: thanks to some intense lobbying in the US it's not treated as hazardous waste.
philipkglass 9y ago
The LD50 for arsenic in rats is 15 mg/kg: http://whs.rocklinusd.org/documents/Science/Lethal_Dose_Table.pdf http://whs.rocklinusd.org/documents/Science/Lethal_Dose_Tabl... The LD50 for strontium 90 in hamsters (90 day survival) is 2 millicuries per kilogram: http://www.rrjournal.org/doi/abs/10.2307/3573895?code=rrs-site http://www.rrjournal.org/doi/abs/10.2307/3573895?code=rrs-si... Given strontium 90's specific activity of 142 curies/gram (https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19680020487.pdf https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/196800...), in mass terms that's 14 micrograms/kg for the LD50. Gram for gram, strontium 90 is about 1000 times as acutely deadly as arsenic, or 40 times as acutely deadly as the chemical warfare agent sarin. If you look at plants built to dispose of sarin, they take something a lot closer to "spent nuclear fuel" levels of precaution than "dump it in a pit" precaution. I agree with you that safety precautions should be by the numbers instead of by psychological reaction, but in a numbers-based regulatory scheme I'd say that we are in much more dire need of increased caution for "mundane" poisons than in need of decreased caution for exotic ones like chemical warfare agents or nuclear fission products.
- saulrh 9y ago
  I believe that nerve agent disposal sites you can find pictures of are all on-site setups at the depots where the weapons were manufactured and stored. In many cases they were disposing of stockpiles of deployment-ready munitions. Care there was not a matter of safety and surety, it was a matter of arms control and international treaty. Field-expedient disposal in an ongoing military situation, on the other hand: It can be, though not without some problems. Mauroni describes a process used in Iraq in 1991. "We'd come across a bunch of rockets, and you suspect there might be some chemicals in them," he says. "The field expedient way, if you're in a hurry, is to blow it up in place." Army Explosive Ordinance Demolition teams would use a 10-to-1 ratio of explosives to suspected chemical weapons. https://www.popsci.com/technology/article/2013-09/fyi-chemical-weapons-and-disposal#page-2 https://www.popsci.com/technology/article/2013-09/fyi-chemic... And yes, there are radiologicals that need to be dealt with more carefully than others. I'm not denying that. 90Sr is about the worst I can think of - its half-life is just short enough for it to be immediately dangerous but also just long enough that you can't stuff it in a box and come back in a year. And I agree that you'd have to treat it with the same immediate care that you would dimethylmercury or VX. The thing is, 90Sr is the worst radiological I can think of. US regulations partition radioactive waste into either low-level or high-level, low-level being things like the gloves the doctor wears when handling the radiotherapy drugs and everything else being high-level. And guess how you have to handle high-level waste? That's right, you have to treat every single kilogram of marginally neutron-activated steel like it's made of 90Sr. That's insane. (that and, well, if you had a lump of 90Sr, burying it in a hole for a million years is a stupid way to deal with it. 30-year half-life; throw it in a shed on a military base, if the US government collapses mail it to another government to stick on their military base. repeat for 300 years and done. if there're no stable governments to mail it to, you have bigger problems.)
  - philipkglass 9y ago
    Per US NRC definitions, High-level radioactive waste or HLW means: (1) Irradiated reactor fuel, (2) liquid wastes resulting from the operation of the first cycle solvent extraction system, or equivalent, and the concentrated wastes from subsequent extraction cycles, or equivalent, in a facility for reprocessing irradiated reactor fuel, and (3) solids into which such liquid wastes have been converted. https://www.nrc.gov/reading-rm/doc-collections/cfr/part060/part060-0002.html https://www.nrc.gov/reading-rm/doc-collections/cfr/part060/p... Given that all American irradiated reactor fuel is still young enough to retain substantial portions of its original strontium 90 (and other medium-lived fission product) content, it doesn't seem like an overly broad definition to me. Maybe in practice things like slightly radioactive steel ends up lumped in with spent fuel? If so, yes, that's bad. I agree that we don't need to bury spent nuclear fuel in permanent geological repositories. Don't try to chemically reprocess the waste, bury it beyond observation, or otherwise convert a simple, compact, inexpensive problem into a more diffuse, complicated, expensive one. Monitored/guarded sheds is fine.

by saulrh 9y ago

DuskStar 9y ago

I'm honestly not sure which direction you mean - should we be really careless with nuclear waste, like we are with heavy metals, or should we treat heavy metal waste with more care?

saulrh 9y ago
Both, meeting somewhere in the middle - nuclear waste is treated way too carefully, and non-nuclear heavy metal waste is treated rather too carelessly. Either way, the important point is for the level of care to be proportional to the actual danger, rather than determined entirely by whether it's called "radioactive" or not.
- eru 9y ago
  Coal ash is even worse in its treatment: thanks to some intense lobbying in the US it's not treated as hazardous waste.

philipkglass 9y ago

The LD50 for arsenic in rats is 15 mg/kg: http://whs.rocklinusd.org/documents/Science/Lethal_Dose_Table.pdf http://whs.rocklinusd.org/documents/Science/Lethal_Dose_Tabl... The LD50 for strontium 90 in hamsters (90 day survival) is 2 millicuries per kilogram: http://www.rrjournal.org/doi/abs/10.2307/3573895?code=rrs-site http://www.rrjournal.org/doi/abs/10.2307/3573895?code=rrs-si... Given strontium 90's specific activity of 142 curies/gram (https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19680020487.pdf https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/196800...), in mass terms that's 14 micrograms/kg for the LD50. Gram for gram, strontium 90 is about 1000 times as acutely deadly as arsenic, or 40 times as acutely deadly as the chemical warfare agent sarin. If you look at plants built to dispose of sarin, they take something a lot closer to "spent nuclear fuel" levels of precaution than "dump it in a pit" precaution. I agree with you that safety precautions should be by the numbers instead of by psychological reaction, but in a numbers-based regulatory scheme I'd say that we are in much more dire need of increased caution for "mundane" poisons than in need of decreased caution for exotic ones like chemical warfare agents or nuclear fission products.

saulrh 9y ago
I believe that nerve agent disposal sites you can find pictures of are all on-site setups at the depots where the weapons were manufactured and stored. In many cases they were disposing of stockpiles of deployment-ready munitions. Care there was not a matter of safety and surety, it was a matter of arms control and international treaty. Field-expedient disposal in an ongoing military situation, on the other hand: It can be, though not without some problems. Mauroni describes a process used in Iraq in 1991. "We'd come across a bunch of rockets, and you suspect there might be some chemicals in them," he says. "The field expedient way, if you're in a hurry, is to blow it up in place." Army Explosive Ordinance Demolition teams would use a 10-to-1 ratio of explosives to suspected chemical weapons. https://www.popsci.com/technology/article/2013-09/fyi-chemical-weapons-and-disposal#page-2 https://www.popsci.com/technology/article/2013-09/fyi-chemic... And yes, there are radiologicals that need to be dealt with more carefully than others. I'm not denying that. 90Sr is about the worst I can think of - its half-life is just short enough for it to be immediately dangerous but also just long enough that you can't stuff it in a box and come back in a year. And I agree that you'd have to treat it with the same immediate care that you would dimethylmercury or VX. The thing is, 90Sr is the worst radiological I can think of. US regulations partition radioactive waste into either low-level or high-level, low-level being things like the gloves the doctor wears when handling the radiotherapy drugs and everything else being high-level. And guess how you have to handle high-level waste? That's right, you have to treat every single kilogram of marginally neutron-activated steel like it's made of 90Sr. That's insane. (that and, well, if you had a lump of 90Sr, burying it in a hole for a million years is a stupid way to deal with it. 30-year half-life; throw it in a shed on a military base, if the US government collapses mail it to another government to stick on their military base. repeat for 300 years and done. if there're no stable governments to mail it to, you have bigger problems.)
- philipkglass 9y ago
  Per US NRC definitions, High-level radioactive waste or HLW means: (1) Irradiated reactor fuel, (2) liquid wastes resulting from the operation of the first cycle solvent extraction system, or equivalent, and the concentrated wastes from subsequent extraction cycles, or equivalent, in a facility for reprocessing irradiated reactor fuel, and (3) solids into which such liquid wastes have been converted. https://www.nrc.gov/reading-rm/doc-collections/cfr/part060/part060-0002.html https://www.nrc.gov/reading-rm/doc-collections/cfr/part060/p... Given that all American irradiated reactor fuel is still young enough to retain substantial portions of its original strontium 90 (and other medium-lived fission product) content, it doesn't seem like an overly broad definition to me. Maybe in practice things like slightly radioactive steel ends up lumped in with spent fuel? If so, yes, that's bad. I agree that we don't need to bury spent nuclear fuel in permanent geological repositories. Don't try to chemically reprocess the waste, bury it beyond observation, or otherwise convert a simple, compact, inexpensive problem into a more diffuse, complicated, expensive one. Monitored/guarded sheds is fine.