Rendered at 17:40:37 GMT+0000 (Coordinated Universal Time) with Cloudflare Workers.
bad_username 3 days ago [-]
"Stable" here means mechanically stable (they don't fall apart as quickly as was expected), not radiologically stable (the radioactive elements, of course, still decay at their normal rate).
readthenotes1 4 days ago [-]
40 years and counting, vs 1 year for Hiroshima
wat10000 3 hours ago [-]
190 tons of nuclear fuel, vs 64 kilograms.
antonvs 4 days ago [-]
Basically, nuclear bombs are much safer than nuclear power plants.
Foskya 3 days ago [-]
next step: use nukes as an energy source
DennisP 4 hours ago [-]
Check out this 1970s project that proposed extracting electricity from thermonuclear explosions.
> A series of 50-kiloton bombs would be dropped into the cavern and exploded to heat the water and create steam. The steam would then power a secondary cooling loop for power extraction using a steam turbine. Dropping about two bombs a day would cause the system to reach thermal equilibrium, allowing the continual extraction of about 2 GW of electrical power
"Hey boss, do you think there is a chance this scheme might introduce radioactive byproducts into the ground water?"
"Shut up"
SV_BubbleTime 3 hours ago [-]
[dead]
drivebyhooting 53 minutes ago [-]
For some reason (that I haven’t figured out yet) thermonuclear bombs are just so much more efficient than any other proposed fission or fusion reaction.
It’s strange that controlled fusion is an energy sink, but whatever black magic is happening inside an H-bomb manages to unlock so much “free” energy.
dopa42365 38 minutes ago [-]
Even the cleanest bombs (97%+ fusion rather than fission) turned out to be too dirty for basically everything civilian (unlocking gas reservoirs - too radioactive; landscaping to replace enormous amounts of conventional explosives - too radioactive).
hallgrim 47 minutes ago [-]
Not really? How do you define efficiency here?
Thermonuclear bombs literally create lots of heat, and don’t tend to drive anything that produces work. It’s the opposite of efficient.
Just like lighting gasoline on fire and claiming that that’s more efficient than a combustion energy…
drivebyhooting 34 minutes ago [-]
I’m talking about net energy. Harnessing it is a whole different story.
jzemeocala 37 minutes ago [-]
What if we used them to run Tesla turbines
Izikiel43 18 minutes ago [-]
In order to trigger an H bomb, you first trigger a regular fission bomb to generate the necessary energy to trigger the second fusion stage.
So, fission bombs are the black magic.
antonvs 3 days ago [-]
Some of the nuclear rocket propulsion ideas propose exactly that, like Project Orion.
HPsquared 2 hours ago [-]
Fission fragment rocket engines are also (theoretically) extremely efficient.. using the particles that come out of the reaction directly as a high-velocity exhaust stream.
drivebyhooting 51 minutes ago [-]
FFR have super high ISP but microscopic thrust. Not exactly practical.
db48x 48 seconds ago [-]
Practical for many missions, just not for sending humans in person to other planets. For example, consider a mission to deliver a telescope out past 550AU so that it can use the whole sun as a gravitational lens. That’s more than 11× further than Pluto, but a fission fragment drive could get the telescope out there in about the amount of time it took New Horizons to fly past Pluto.
Izikiel43 17 minutes ago [-]
did they ever figure out how to brake? Spin the ship 180 degrees and bomb the front?
hedgehog 4 hours ago [-]
If you like Orion check out Project Pluto (they even built some some test bench engines)
eqvinox 4 days ago [-]
The headline sounds weirdly positive... but it's "stable" as in [ed.: ecologically] "long-lived". Very much not a good thing.
timr 4 hours ago [-]
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.
kitchi 2 hours ago [-]
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.
boxed 4 hours ago [-]
I think they mean that the fuel rods are not breaking down, aka leaching into the environment, as fast. That's a good thing.
Mutjake 4 days ago [-]
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.
eqvinox 4 days ago [-]
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.
(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.")
https://en.wikipedia.org/wiki/Project_PACER
> A series of 50-kiloton bombs would be dropped into the cavern and exploded to heat the water and create steam. The steam would then power a secondary cooling loop for power extraction using a steam turbine. Dropping about two bombs a day would cause the system to reach thermal equilibrium, allowing the continual extraction of about 2 GW of electrical power
"Shut up"
It’s strange that controlled fusion is an energy sink, but whatever black magic is happening inside an H-bomb manages to unlock so much “free” energy.
Thermonuclear bombs literally create lots of heat, and don’t tend to drive anything that produces work. It’s the opposite of efficient.
Just like lighting gasoline on fire and claiming that that’s more efficient than a combustion energy…
So, fission bombs are the black magic.
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.
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.
Of course radioactivity needs to be respected, and the exclusion zone is there for a reason due to factors such as hot spots.
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.")