Google commits to buying power generated by nuclear-energy startup Kairos Power

I love the 'ideally' in the dry cask storage article...

"Ideally, the steel cylinder provides leak-tight containment of the spent fuel."

Also guessing that article is woefully out of date since it mentions:

"The NRC estimated that many of the nuclear power plants in the United States will be out of room in their spent fuel pools by 2015, most likely requiring the use of temporary storage of some kind"

"Ideally, the heavy steel mills near Lake Michigan will produce minimal heavy-metals-laden effluent"

Safety claims of novel, unproven fission designs always come with a crazy footnote. Pebble bed reactors are completely safe, if they are never exposed to water or oxygen, which is a pretty hilarious caveat for planet Earth.

What are the disclaimers for molten salt reactors?

Considering that there are no commercial-scale operating MSRs, I am guessing there are some pretty significant difficulties. Like graphite pebble reactors, molten salts must be perfectly desiccated, which is impossible to guarantee under Earth operating conditions, and nobody knows what kinds of materials to use for the salt containment, or how it might be changed by a few decades of operation.

If you can contain the highly corrosive, very hot, molten salts, then they are fairly safe, but you do need to guarantee that the path to the dump-tanks is undisturbed by whatever disaster is necessitating their use.

A big non-safety disclaimer is that the proposed advantage of online refueling is still largely theoretical.

The best thing about nuclear, IMHO, is that all of the highly radioactive waste ever produced by nuclear power plants in the US could fit into a single football stadium. Compare that to coal, oil, natural gas, etc.

It's not too hard of a problem to solve, it just requires political will to bury it in a dry geologically stable desert somewhere in the US, which we have plenty of.

> all of the highly radioactive waste ever produced by nuclear power plants in the US could fit into a single football stadium.

I have heard this before, but is this just the physical waste's volume? Isn't that a useless metric? What would happen if you included the volume of the containers required to safely house it?

No one has built a large scale viable one yet because of the extremely caustic coolant. In theory they sound great, but no one has come up with a material that can survive the molten saltfor decades

> What would happen if you included the volume of the containers required to safely house it?

Immensely more manageable than e.g. toxic, radioactive coal ash [1]. TL; DR Spent fuel isn't a real problem. We dispose of tonnes of similarly-nasty stuff every day without mention. (And unlike with radiation, it's difficult to indpendently check chemical toxicity.)

[1] https://www.wsj.com/us-news/coal-ash-cancer-epa-north-caroli...

Sure, but I just mean that if you put all the nuclear waste into a pool-sized container, is there not a chance that it would go critical without safe housing and separation?

Coal ash doesn't have that feature.

> if you put all the nuclear waste into a pool-sized container, is there not a chance that it would go critical without safe housing and separation?

Not really. Even intentionally turning nuclear waste into a critical mass would take some effort, assuming it's been minimally reprocessed.

`not too hard a problem` - just hard enough that it hasn't been progressed for decades.

but the great thing about next gen reactors is that the waste solution does not need to be addresed; any waste from next gen reactors will simply go wherever the final solution for existing waste engines lands.

if you could, that's no longer waste, it's unused fuel.

> just hard enough that it hasn't been progressed for decades

That's the thing, though: it doesn't need to progress, it's essentially solved. At least, for our current usage

there aren't any records in history with problems with casks storing solid waste. Related to spent fuel: the solution should be storage facility like in sweden + purex like in France (or even better - fast reactors and pyroprocessing)

The volume of nuclear waste is completely overestimated by the man-on-the-street.

https://ukinventory.nda.gov.uk/the-2022-inventory/2022-uk-da...

A bit like all the world's gold would actually comfortably fit into an olympic sized swimming pool.

https://www.bbc.co.uk/news/magazine-21969100

Nuclear waste is a bit larger because it's not pure radioactive elements, but it is still a tiny volume.

I believe it depends on the salt used and why a lot of research is looking at fluorine - floride salts don't dissolve in water and thus don't have the same risks. Another MSR design seeing a lot of attention is SSR which similarly doesn't use any chemically reactive materials. SSR is also interesting from a cost perspective as it's projected to cost half of a modern coal power station and almost a third that of a modern large scale nuclear construction putting it in line with solar plants that don't have batteries (i.e. much more cost effective).

> And unlike with radiation, it's difficult to independently check chemical toxicity.

This was always kind of interesting to me, and I'm surprised it's not mentioned more. Not for any practical purpose, but just because you'll often hear people talk about how radiation is super scary because it's "invisible". Which is the case, sure, but it seems like it's hardly unique? As you implied, there's countless chemical contaminants that are just as dangerous, and just as undetectable by human senses. At least with radioactive contaminants you can (at least in most situations) use Geiger counters and dosimeters and whatnot - with some of the chemical threats humanity has cooked up, it seems like you need an entire study just to determine if they're present or not.