One approach is more integration of researchers with businesses. Fraud (or simple incompetence) by researchers negatively affects businesses, as they expend effort on things that aren't real. I understand this is a constant problem in the pharmaceutical industry.

It's quite possible to be very successful marketing and selling things that aren't real. The market consists of humans, not perfectly rational machines.

And funding dedicated to replication studies.

paid by the original authors if their study fails to replicate

Constitutional protections aren't trumped by mere issues of governmental convenience.

Where is this, Poland?

Unlikely. Manufacturing in Poland is booming, not a slow death as GP said. Maybe Romania or Bulgaria.

Thanks.

It's as if Trump was looking for another way to tank the GOP in the fall election.

Literally an arc.

Albedo modification (stratospheric aerosols) seems much cheaper than direct air capture, as a stopgap.

That unfortunately doesn’t help with ocean acidification.

We simply drop a giant tub of baking soda into the ocean every now and then.

Thus solving the problem once and for all

https://www.youtube.com/watch?v=VW66EX75jIY

The research isn't there. Jury is still out on whether the long term consequences are a net benefit. In the end you're talking about increasing emissions for a temporary decrease in temperatures. And the chemicals we have that are good candidates for albedo modification are quite toxic. Today more than 10% of deaths globally can already be attributed to air quality

Humans tend to not breathe in a lot of stratospheric aerosols, on account of that being pretty high up.

As they sink down, they grow larger (condensation & coagulation). Once they reach the troposphere, they usually get down via precipitation, which also isn't really affecting a lot of breathing.

They can absolutely have other effects (see SO2/acidification, e.g), but air quality isn't really the main concern. For SO2 specifically, there's actually very little mortality sensitivity: https://www.giss.nasa.gov/pubs/abs/wa01010x.html

You're right that the research isn't there yet to make statements with confidence, but that applies to the air quality claim as well.

If India is experiencing large scale mortality from warming, they aren't going to give a damn about your concerns. They're just going to inject aerosols into the stratosphere.

India especially is experiencing many more deaths from air quality than from warming

Bismuth leads to the production of polonium, which is extraordinarily dangerous.

> 5 years

Be careful with these figures. I understand they start the clock later than the west does.

Do they? Did japan start the clock later too with it's first ABWR?

We weren't talking about Japan.

We were talking about timelines. Chinese timelines are faster than western but slower than Japanese. So maybe you can expand your thought about how China is counting years differently

Fast reactors have an extremely serious potential failure mode.

In a thermal reactor, reactivity is maintained by a carefully designed lattice of fuel elements and moderator. Disrupt this lattice and reactivity goes down. Thermal neutrons are also highly absorbed by certain neutron poisons with resonances that enable neutron capture at low energy; these can be added to shut down any potential reaction.

Fast reactors aren't like that. If fuel rearranges (for example, by melting and flowing into coolant channels) reactivity can increase. A fasts reactor will have ~100 times the "bare core" critical mass of fissionable material in it, so there's plenty of room for serious rearrangement to bring fission material into a prompt fast supercritical configuration.

That by itself could give you an explosion. But if the explosion then compresses some other part of the system beyond supercriticality, one could get an even more serious explosion. The possibility with something with a yield in the kiloton range can't easily be ruled out. This would be far worse than Chernobyl.

The fast reactor concepts I've seen deal with this by saying "our design can't ever melt down". Color me skeptical on that, and defense in depth says you don't believe such claims when failure could be so catastrophic. Even if regulators can be convinced (or be made to say they are convinced), the first experience that indicates the assumption wasn't true will lead to all reactors of that design being permanently shut down. This would be a serious financial risk to anyone thinking of building them.

If I were dead set on a fast reactor I'd look at something like a fast MSR (chloride salt) where such rearrangement could be ruled out.

Not sure about this argument, do you have any references?

In a LWR, if the coolant/moderator boils away, sure, the reactivity goes down. But there is plenty enough decay heat left to melt all the fuel that can then flow into a puddle of suitable geometry and go boom. Hypothetically speaking, at least.

I suppose in practice most LWR's use lightly enriched fuel so it's very hard to get enough material close enough together to make it critical, let alone supercritical, without a moderator of some sort. Of course, plenty of research reactors, naval reactors etc. have operated with very highly enriched fuel (90+%?), but even these have AFAIU so far managed without accidentally turning themselves into nuclear bombs.

Seems most contemporary civilian fast reactor designs are designed to operate with HALEU fuel, where the limit is (somewhat arbitrarily) set at 20%. A lot higher enrichment than your typical LWR, but still much lower than you see in weapons, and you still need quite a lot of it before it can go boom.

It's straightforward. Consider what would happen (for example) if all the fuel in a reactor is compressed into a more compact configuration.

In a thermal reactor, there's no problem, as there's now no moderator. There was massive rearrangement and compaction of melted fuel at the TMI accident, but criticality was not going to be a serious issue for the fundamental reasons I gave above.

In a fast reactor? It can only become more reactive. Anything else there was only absorbing neutrons, not helping, and the geometric change reduces neutron leakage.

Edward Teller somewhat famously warned about the issue in 1967, in a trade magazine named "Nuclear News":

“For the fast breeder to work in its steady state breeding condition, you probably need half a ton of plutonium. In order that it should work economically in a sufficiently big power producing unit, it probably needs more than one ton of plutonium. I do not like the hazard involved. I suggested that nuclear reactors are a blessing because they are clean. They are clean as long as they function as planned, but if they malfunction in a massive manner, which can happen in principle, they can release enough fission products to kill a tremendous number of people.

… But if you put together two tons of plutonium in a breeder, one tenth of one percent of this material could become critical. I have listened to hundreds of analyses of what course a nuclear accident could take. Although I believe it is possible to analyze the immediate consequences of an accident, I do not believe it is possible to analyze and foresee the secondary consequences. In an accident involving plutonium, a couple of tons of plutonium can melt. I don’t think anyone can foresee where one or two or five percent of this plutonium will find itself and how it will get mixed with other material. A small fraction of the original charge can become a great hazard."

(Natrium is not a breeder but the same argument holds.)

That no fast reactors have yet exploded is of course no great argument. How many fast reactors have been built, particularly large ones? Not many. And we've already seen a commercial fast reactor suffer fuel melting (Fermi 1).