Chernobyl particles reveal unexpectedly stable nuclear fuel after 40 years (phys.org)

118 pointsby geox4 days ago42 comments

bad_username 4 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).

wjnc 4 hours ago

Thank you! Geigerclickbate?

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.

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.

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.")

boxed 8 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.

db48x 4 hours ago

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.

timr 8 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 7 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.

readthenotes1 4 days ago

40 years and counting, vs 1 year for Hiroshima

antonvs 4 days ago

Basically, nuclear bombs are much safer than nuclear power plants.

Foskya 4 days ago

next step: use nukes as an energy source

antonvs 3 days ago

Some of the nuclear rocket propulsion ideas propose exactly that, like Project Orion.

hedgehog 9 hours ago

If you like Orion check out Project Pluto (they even built some some test bench engines)

HPsquared 6 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 5 hours ago

FFR have super high ISP but microscopic thrust. Not exactly practical.

db48x 4 hours 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.

drivebyhooting an hour ago

For that particular mission I’d be curious to compare to an ion drive architecture.

Izikiel43 5 hours ago

did they ever figure out how to brake? Spin the ship 180 degrees and bomb the front?

Melatonic 3 hours ago

Couldn't you just turn and orbit ?

hinkley 2 hours ago

… without irradiating yourself?

DennisP 8 hours ago

Check out this 1970s project that proposed extracting electricity from thermonuclear explosions.

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

jandrese 8 hours ago

"Hey boss, do you think there is a chance this scheme might introduce radioactive byproducts into the ground water?"

"Shut up"

euroderf 7 hours ago

Coming soon: thermonuclear fracking.

vjvjvjvjghv 6 hours ago

Already done https://en.wikipedia.org/wiki/Project_Gasbuggy

euroderf 6 hours ago

There goes another grant proposal into the bin...

ryoshu 4 hours ago

In the end we're just boiling water.

kristianp an hour ago

There was also project Plowshare, as chronicled by Kurzgesagt at https://www.youtube.com/watch?v=h3DCdWyb0cc

Which was building canals etc with nuclear bombs. https://en.wikipedia.org/wiki/Project_Plowshare

drivebyhooting 5 hours 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.

hallgrim 5 hours 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…

jzemeocala 5 hours ago

What if we used them to run Tesla turbines

drivebyhooting 5 hours ago

I’m talking about net energy. Harnessing it is a whole different story.

Retric 2 hours ago

Not really making nukes take a ridiculous amount of energy and you only get to use it once where the energy to create ITER gets split across its operating lifespan.

Further fission here requires a fission first stage which represents a huge additional energy input.

drivebyhooting an hour ago

GPT pro says 3 to 30x energy release compared to the entire supply chain input for a megaton class weapon.

I trust the argument. You can look into it yourself. Long story short, it is massively energy positive compared to controlled fusion.

dopa42365 5 hours 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).

Izikiel43 5 hours 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.

drivebyhooting an hour ago

I think there’s a lot more to it than that, like the heavy uranium tamper, “FOGBANK”, and radiation implosion (whatever that means).

It’s a much more efficient version of inertial confinement fusion like at the NIF.

Tuna-Fish 4 hours ago

Fusion is ridiculously efficient and effective power source. The problem with it is that it is very hard to created conditions where fusion can happen. The one reliable way we have that doesn't take more energy in than it outputs, is to detonate a fission bomb and use the x-rays to compress a fusion secondary.

The history of fusion research for the past 70 years is trying to figure out a cost-effective way to trigger enough fusion to make net energy without a nuke. So far, we've got bupkis. (The magnetic containment approaches using high-temperature superconductors seem promising, but we won't know they actually work until we've built them.)

LtdJorge 4 hours ago

Much safer than newly built reactors using decades old designs for making Plutonium used as power generators, with every safety feature forcefully disabled and during a drill to investigate the feasibility of a condition live, the effects of which weren’t known by any operator and the drill hadn’t been tested in an offline experiment before nor was it even simulated. Then, maybe.

bawolff 40 minutes ago

Nuclear bombs are meant to go boom. Any part that doesn't go boom is waste whose weight could be better allocated to making it have a bigger boom.

wat10000 8 hours ago

190 tons of nuclear fuel, vs 64 kilograms.

dwroberts 2 hours ago

It was a power plant full of fuel, why is this surprising?