Small nuclear reactor design to be approved

It has been done, and even done at scale. Do you have links / opinions about why it hasn’t been successful, in the sense of “people do it regularly”?

The Wikipedia link you provide lists “Notable breeder reactors”, and it’s got 21 entries spanning 50 years, most of which have under 100 MW output (less than 1/10th a typical nuclear power station). I’m genuinely trying to update my knowledge on this.

ETA: I’m guessing it’s a mix of things, but I have no feel whether the big barriers were capex (expensive to build), opex (expensive to operate), or technical challenges.

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I’m definitely not the one to explain, but… seems like the older generation of breeder reactors required a fuel reprocessing step, which meant plutonium was being extracted, and that raised proliferation concerns. It seems to me this was mostly a very political move to get reactors stopped, and it worked. Carter put a freeze on fuel reprocessing, and that made waste a problem, and that made reactor development stop for a couple of decades.

I’m not sure if the fuel reprocessing step has to be there, or if there are better designs now that can skip it, or better ways to do it. Google it! Sorry, but it’s actually pretty interesting subject.

All of this is why I believe that nuclear “waste” is ridiculous, and we can go ahead and build a storage facility that lasts thousands of years, but all that stuff is going to be dug up and used as fuel within a couple of decades.


I agree this is a crucial component, but honestly I think we’re making good progress here. Electric cars, for example, are primarily an efficiency win. Even if the power for them is made from fossil fuels, they are so much more efficient that they are a huge win regardless. The Chevy Bolt, for example, goes 250 miles on the equivalent energy of 3/4s of a gallon of gas. More and more countries are implementing carbon taxes as well, which is extremely incentivizing for efficiency.

I don’t think we need to use nuclear for everything- it just needs to cover the base load lost by shutting down coal. We could probably keep most of the natural gas, honestly. The carbon footprint of that is low enough that we can probably recover or capture it (or live with it until grid storage comes online).

Yucca Mountain alone could probably take all the nuclear waste generated in the whole world, if we built the modern efficient breeder reactors (not the crappy ‘60s designs that only use 1% of the fuel as others pointed out upthread). We could have two entire generations of modern reactors that operate entirely on the waste of previous generation ones, meaning no waste at all. All the waste generated from every current nuclear plant built since 1950 is all sitting in storage pools next to those reactors. That’s all fuel for newer designs.


I think everything moved about as fast as it could have, honestly. Maybe we could have spent more on R&D in the ‘90s, but there’s no guarantee of increased speed from that. The technology hurdles of grid storage probably weren’t gonna get solved faster, unfortunately. Those are really hard problems and if we had rushed, we probably would have built a bunch of crappy batteries and low-efficiency solar panels that we’d now be replacing anyway.

What we really needed to do sooner was get rid of oil subsidies that keep fossil fuels artificially cheap. That would have put renewables on a level playing field a lot sooner and we’d be farther ahead on conversion and grid upgrades by now.


Now, now, let’s not exaggerate. Some of it is sitting around in warehouses and some of it is buried in former salt mines in quietly corroding containers.


Oh hell yes.

Episode 7 Nbc GIF by One Chicago


Minor quibble - the big breakthroughs in solar panels mostly hinge on manufacturing cost, not panel efficiency. Both price and efficiency factor into the cost of energy. But since 1990, panel efficiency has almost doubled, and the price per kW is less than 1/10th.

I was as surprised as anyone that the big breakthrough wasn’t affordable 30+% panels, but cheap-as-chips 20-ish% panels.

In Australia, we have a lot of sun and a lot of open space, so the math works out very well for “lots of cheap panels”. The math might be very different in, say, Belgium.

But also: we’d be replacing the panels and batteries every 10 to 15 years no matter what we made them out of. :slight_smile:

ETA: Price of solar:


This is very easy to say if you haven’t grown up within the fallout zone of Chernobyl as I have, and a large percentage of Europeans have. This was one accident at one plant and I still couldn’t eat mushrooms foraged in the woods or boar shot locally when growing up. And that’s a problem that is still going to plague generations to come.

People will say that this was the fault of lax Soviet training and security measures but the thing is, I don’t trust cost cutting businesses in our capitalist system any more to have the public’s safety in mind, and Fukushima proved that theory pretty decisively.


This is another issue with nuclear fission. It feels like it would work great for a less short-sighted species.


Yes. I can kind of understand why STEM people tend to be enthusiastically pro nuclear. It can work safely and efficiently in theory! However, as the kids say, we live in a society.


You don’t know where I grew up.

But again, I ask- what is your alternative. The only ones I generally hear are vague promises of grid storage solutions that are sure to come around Any Day Now or arguments from people who don’t understand the magnitude of the grid storage problem. The arguments against nuclear are always things nobody wants, but are all better than catastrophic climate change.

The disasters we’ve had from nuclear are terrible, without question. It’s not a technology we want to rely on for long. If you’ve got a better alternative, I’m all ears. 3°C climate change is going to make Chernobyl seem like a walk in the park.


I thought in Canada, but I apologise if I’m wrong.

For nuclear waste storage, Finnish Onkalo (“Cavity”) is IMO a pretty damn solid solution.


Kenan Thompson Reaction GIF by Saturday Night Live


One thing I remember from a few(?) years ago is molten salts. The solar plant heats up the salts during the day so that the molten salt still gives off enough heat at night to provide steam etc.(I think they tested this in a desert in Chile – the salt was at the top of a tower, like the Eye of Sauron, in the middle of the complex. I wouldn’t be surprised if I read about it here at BB.) But I haven’t heard that the technology progressed any further than making nuclear power fuckups less catastrophic.

Same with thorium reactors – I recall hearing more about them 8 or 10 years ago, then there was some kind of general consensus that it wouldn’t work, at least not yet (but, again, 8 or 10 years ago).

Also the grinder pump in my basement looks a lot like the “small nuclear reactor design” so now I have to be more careful when its needs another replacement in a few years…

That exists and it’s not a grid storage method, it’s an alternative method of making solar power. A bunch of plants were built like that in California as well, back before solar panels were efficient enough and cheap enough to make power photoelectrically, it was cheaper to do it thermally with mirrors and a molten salt heat exchanger.


Sometimes it’s for storage.

To give one example, in Australia Vast Solar are doing using liquid sodium as their solar energy collector fluid (or at least, that’s what they were using in 2017 when I last looked in on them - not sure if they’ve stuck with that). They pump the liquid sodium through a heat exchanger to make superheated steam.

Years prior to that, I worked on a prototype that used solar to heat molten salt. The use-case we pictured was to store heat during the day, and use it during e.g. the evening peak. It never got past prototyping the components, but the company had bigger problems than its little molten salt project and folded early into this experiment, so it’s hard to say whether it would’ve been practical.


Well, molten salts are going to be very corrosive. Maybe that makes it impractical at large scale?


Less than you’d think. Remember, there’s no water or oxygen in the pipes.

As an example of something similar: It often surprises people that you need special alloys to pump 90% sulphuric acid, but 98% can be pumped in mild steel pipes - again, no water.

Another factor is that if you over-build renewables, you can then get into some of the more promising longer term storage options, such as all the “energy to gas/liquid” technologies. These put out either Hydrogen gas, Ammonia or methane, all of which can then be used industrially or stored in the existing fossil fuel infrastructure and burnt later using traditional turbines, for time-shifted electricity.
There’s currently a lot of work going on researching better catalysts and electrolising setups for these processes, that have the additional benefits of giving a pathway to gradually decarbonise using existing infrastructure, and to replace the current methods for generating important chemical feedstocks, without the current need for a huge amount of natural gas.

Of course, all this is easier if there’s a reliable chunk of baseload already taken care of, but the cost of that is another big factor.