4 ms·
> Caesium 137, which has a 30-year half-life and decays slowly Forgive my layman's ignorance, but "decays slowly" is just a less precise version of the "30-yea
by CoastalCoder 6y ago
> Caesium 137, which has a 30-year half-life and decays slowly
Forgive my layman's ignorance, but "decays slowly" is just a less precise version of the "30-year half-life" statement, right?
- bluGill 6y agoEither way it is wrong. 35 years is fast enough to not worry about long term. It only takes a couple centuries for anything with a half-life that small to complete decay. For nuclear waste we worry about things with half-lives in the thousands of years as we can't be sure we can store it for as long as it is dangerous. The real question then becomes what does it decay into? A lot of things decay some something with a dangerously long half life.
- refurb 6y agoBut, half-life and hazard are related as well. If atoms aren’t decaying (and spitting out alpha, beta particles or gamma rays) they aren’t much of a radiological hazard. Short-half life means more radiation hazard.
- Pyramus 6y agoI'm not sure I understand, are you saying we should not worry about immediate effects that only affect 1 or 2 generations? I don't see why thinking about negative effects over different timespans should be exclusive - climate change certainly won't be an issue in thousands of years (if we still exist).
- bluGill 6y agoI'm saying 30 year half lifes are still considered short. We still need to worry for a few generations, but that is enough to remain in memory. If we forget about the problem in 300 years - that is 10 half lives and so it isn't a big deal. If something has a 1000 year half life it will be dangerous far longer than we can remember to watch out.
- Someone 6y agoYes, but assuming equal mass of radio active material and identical radiation output something with a half-life of 1000 years is less dangerous, radiation-wise (it still might be more poisonous) Caesium is often brought up in this kind of discussions. I think one reason might be because it decays fast enough to be harmful and still slow enough to be harmful for considerable time. Another reason might be that more of it gets released in your typical nuclear accident. I wouldn’t know whether that is true.
- bluGill 6y agoMy point is about what is considered a long time, not relative dangers. Caesium is bad for a few hundred years. Some things are not as bad overall, but over the next 10,000 years is worse. Caesium in fact has been through one half life, and so is half as bad as it was at the start.
- Pyramus 6y agoWhy would there be disagreement about what is considered a long time? You are arguing that longer half life = bad, shorter half life = less bad, which misses the point. An effect with a shorter half-life could be a lot worse/more dangerous/threatening (potentially apocalyptic) than an effect with a longer half life.