The headline sounds weirdly positive... but it's "stable" as in [ed.: ecologically] "long-lived". Very much not a good thing.
The headline sounds weirdly positive... but it's "stable" as in [ed.: ecologically] "long-lived". Very much not a good thing.
It means "mechanically stable", which could be either good or bad depending on the question, but is generally a limited good thing.
At the least, it means these particular compounds aren't quickly breaking down into ever-smaller nano-particles that can be absorbed into living things.
This is tangentially related to the article, but it's interesting that the phrase "unexpectedly stable" triggers positive connotations. It did for me as well.
But the phrase is actually neutral, it's not making any claims if stability is a good or bad thing in this context, neither about "unexpected" stability. But given the larger context of language we read it as positive.
I think they mean that the fuel rods are not breaking down, aka leaching into the environment, as fast. That's a good thing.
It’s hard to call them “rods” at this point, since they melted and then cooled into tiny metallic droplets and shards after they were ejected in the explosion.
For radionuclides more long-livd means less radioactive per unit of time, though. Of course uranium compounds can be toxic in the chemical sense as well, but I’m unsure if uranium compounds make it to the top threats in that list compared to e.g. arsenic and lead.
Of course radioactivity needs to be respected, and the exclusion zone is there for a reason due to factors such as hot spots.
This is "long-lived" in the ecological sense, not radiological. The grains of uranium oxide dust remain grains of uranium oxide dust, rather than breaking apart. If you ingest a few molecules of uranium oxide, it pretty much doesn't matter, you're fine¹. Ingest these dust particles, not so much. It's a question of concentration, and it seems that it's not diluting out naturally.
¹ humans contain, on average, 90µg of uranium. [https://www.iaea.org/sites/default/files/DU_Eng.pdf]
(P.S.: the radiological stability and lifetime of uranium doesn't make much sense to question; the dust flakes aren't large & concentrated enough to significantly shorten their half-life due to their own neutron emissions cascading and this isn't what the study was researching. Note the article talks about weathering: "It remains largely unclear why these particles weather at different rates in their environment.")