If you vitrified it first honestly it'd probably be totally fine. An arguably better plan is just get serious about reprocessing and work towards cleaner processes than PUREX. Not even necessarily a completely new process, just better controls around handling waste and making sure there's no massive liquid tanks just waiting to leak into the ground like the Hanford site. Most spent fuel is depleted uranium and not exceptionally dangerous to be around. If you can separate out the fission products and transuranics then you could drastically reduce the amount of waste needed to be stored, store it for less time, and potentially recycle some and get some actual use out of what is currently considered waste.

Just dumping fuel pellets into the deep ocean would be a pretty terrible idea though. All the fission products and impurities that build up as the fuel is burned lead to the pellets starting to crack apart. Any cesium or iodine would leach into the water quickly, it would not be a good day for Shamu.

Vitrified waste is, despite naive assumptions, porous

Er, but it's still vitrified and stable as a glassy material that's less prone to leaching fission products into any water right? As far as I understand it, the whole point of vitrifying it is to trap anything and everything aside from Xenon and Tritium into the vitrified end product.

Momentarily, yes. Longer term, no.

There's life down there.

Pretty basic one even that is in a fundamental part in the food chain many successive chains depend on.

No

https://theecologist.org/2009/mar/01/somalia-used-toxic-dump...

That doesn't really show anything because it's such a huge mixture and the vast majority is random toxic chemicals, not plain old spent fuel.

I'm not saying I think dumping nuclear waste in the ocean is a good idea (though I am also curious if there's been specific impact studies done on it, if we're talking about very very deep ocean) but I'm pretty sure somalia isn't in the ocean.

They were dumping waste off the coast of Somalia, in the ocean

"Bottom of the ocean" here doesn't mean on the continental shelf.

The historic problem of just 'drop it in the ocean' is that (so far) it almost always comes back to bite you. Hence the thousands of rusting barrels of DDT off the coast of California.

https://www.latimes.com/environment/story/2021-04-26/ddt-was...

Did I say thousands? Wow.

Don't ever trust anyone that says "We'll just safely dispose of that in the deep ocean.".

WP's article about this is quite good, and leads to a terse but to the point "Ocean floor disposal" one: https://en.wikipedia.org/wiki/Ocean_disposal_of_radioactive_...

Most of this seems to indicate minimal environmental effects?

Minimal measured effects (few studies), the key here is the precautionary principle, applied here by the "London Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter", https://en.wikipedia.org/wiki/London_Convention_on_the_Preve...

Isn’t what we’re doing right now is essentially dumping used fuel into a monitored and confined ocean (ie water tank on site)