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The only circumstances I can think of in which the decay of radioactive waste might be unknown is in the case of mixed waste where the content or origin is unkn
by andyjohnson0 11y ago
The only circumstances I can think of in which the decay of radioactive waste might be unknown is in the case of mixed waste where the content or origin is unknown or ambiguous. Some old waste material might fall into that category, but I don't think that recent spent reactor fuel would.
- arethuza 11y agoMy understanding is that radioactive emissions are readily measurable so what elements/isotopes are involved should be identifiable and therefore the rate at which these will decay will be predictable - this could well be wrong! One potential other risk is chemical instability of nuclear waste materials - that has caused lots of problems e.g. the Kyshtym disaster: https://en.wikipedia.org/wiki/Kyshtym_disaster https://en.wikipedia.org/wiki/Kyshtym_disaster Edit: Modified the first part to make it clear that I should have been asking a question rather than making a statement!
- andyjohnson0 11y agoIs it possible to precisely identify the composition of a body of mixed waste solely from its emissions? Wouldn't chemical analysis of a sample be necessary?
- kijin 11y agoTwo substances might emit the same kind of particles, but their rate of decay will be different. Measuring the emissions of a container over a period of several years will probably yield enough data points to solve for all of the unknowns.
- hga 11y agoAlso the energies, specifically of the more penetrating gamma rays (very energetic photons). And the more dangerous stuff has shorter half-lives, so it wouldn't take all that long to get the full picture. WRT to nuclear weapons, we can determine what the fissionables were, where they were mined, and some details of design all from sniffing the air downwind.
- VLM 11y ago1) Yes its extremely trivial, aside from shielding and non-homogenous and screwing up issues. 2) Yes because for example glass is stable in acid and unstable in some alkali so neutralizing the "stuff" before mixing it into glass bricks for all eternity would be Highly advisable if you want the glass brick to be unchanged for 100K years or 1M years or whatever. Aside from acid/base reactions with the glass itself there are solubility situations where a simple reaction might convert some radioactive salt that is highly soluble in water to something that's essentially waterproof. Note that the glass for vitrification is not exactly mere window glass, its some weird stuff, and adjusting its mix might help depending on what you're trying to dissolve into it. (edited to extend answer #2, most of the waste you put into a vitreous block is not radioactive, you can't use the gear from answer #1 to tell what most of it is made out of) On a high level this overall discussion has gone off the rails because the 100K and 1M numerological numbers come from glass vitrification and stainless steel corrosion theoretical studies; it has little to nothing to do with radioactivity; you could vitrify coal ash or industrial waste or Atari 2600 game cartridges the same way for 1M years if you felt like it. Or at least people think that storage tech will last 100Kyrs Of course radioactive waste is harmless once it finished decaying whereas arsenic is forever so its kinda pointless to try and stockpile industrial waste for 1Myrs whereas nuclear waste is the only kind of waste that actually goes away with time. No human has ever made an industrial artifact that's lasted 1M years so things are kind of fuzzy at that kind of extrapolation.
- DennisP 11y ago1) Is this because the emitted particles have different energies when they come from different isotopes?
- VLM 11y agoYes. The resolution and dynamic range you can get with modern gear is pretty impressive. Check out images.google.com with terms like "gamma spectrum". Also different kinds of particles. Also you can zap things with neutrons (and other things) and the reactions tend to be rather unique. Given a large enough amount of money to outfit a lab, its very fast and easy to tell whats inside an unshielded box. If its a thick enough shielded box, exact minimal design probably classified, then you'll have to crack the box open or stick a sensor in a hole. Its trickling down to consumer level. Junkyards can now afford an x-ray zapper than analyzes the exact metal alloy of scrap that comes in. Its interesting that when I was a kid things like FLIRs and xray analyzers were very star trek, but within my lifetime they're going to be nearly consumer goods. If you thought police visual cameras and airport xray scanners were controversial, wait until every podunk police dept has 500 FLIR cameras on lampposts and every car that drives by is remotely analyzed for drug or gun or explosive signatures all for your "safety".
- thomasrossi 11y agoContaminated lumber, clothes, plastics, that mixed material can be difficult to valuate indeed and uses a lot of space too, so it gets incinerated.