I would say proliferation resistance is nearly completely irrelevant.
There are hundred of weaponizable reactors in not really good places of the world. In case of the next big war, nobody will ask IAEA for permission to build the nuke.
As some the saying goes, the genie is long out of the bottle.
This is short sighted. This isn't about getting the genie back into the bottle but about sharing nuclear technology with developing countries that we otherwise can't help because they'd need a source of enriched uranium and it'd provide them with an industrial source of weapons grade radioisotopes.
This is one of the few ways we can shortcut the developing world's reliance on fossil fuels while still supplying plentiful base load power that can grow with them.
"Developing countries" with an axe to grind on USA already have dozens of research, or power reactors. This is my point.
If somebody will bomb your cities with nukes, killing millions in the process, you will not need Mariano Grossi, he will be useless to USA. You will need capable military allies.
So far, the US does everything to turn away any potential ally, including by denying them access to powerful weapons, with thermonuclear weapons being the biggest one.
> "Developing countries" with an axe to grind on USA already have dozens of research, or power reactors reactors.
Right. This isn't about them. This is about all the other developing countries that don't. This is about making them allies by giving them nuclear technology, something that the developed world is terrified of doing because of nuclear proliferation. That's why proliferation resistance is relevant.
If any of them really wanted so, they would've build a small clandestine reactor somewhere long time ago.
Nuclear bombs are forties technology. Industrial output of forties USA is met by dozens of countries today.
People continuing to advocate for non-proliferation cannot believe the that the most basic point of theirs is false: from technical viewpoint, from logical, political, and military one.
Of course they can, but they don't. It's extremely expensive and the vast majority of countries can't afford the massive upfront cost without nasty consequences. Most of the 32 countries with nuclear reactors built them using technology from Russia, France, the US, UK, or China. China still builds nuclear reactors using imported Russian technology because its own industry can't keep up with the demand - the demand for exporting Chinese nuclear reactors to countries that US/EU won't sell nuclear technology to.
The article we're commenting on is part of the EU and US response - they want to sell their reactor technology to a bunch of countries to prevent China from getting that business and gaining influence, but they want to do it in a way that reduces proliferation because the constituents that vote for them care about nuclear proliferation. It's entry level geopolitics.
But then, they would have to get fissile material, which isn't exactly an open market. It's easy to justify buying the material if you have a commercial reactor to feed it to, not so much if you don't.
In fact, international inspection mechanisms worked pretty well so far.
> they would've build a small clandestine reactor somewhere long time ago.
And have some advanced nation genocide all the relevant brains on your country? I would try to lead them in some other enterprise, even better if it doesn't have to be clandestine.
The only reason one needs enriched uranium is because of political pressure from nuclear-armed countries to both force everyone to use reactors that require enrichment and take control of availability of enriched fuel.
NPT with annexes is already plenty enough to prevent hidden repurposing of waste into weapons, it just doesn't fit American immediate econopolitical wants.
It's not an all-or-nothing issue. Every single reactor that produces weapons-grade material increases the risk.
Because it's not just state actors you need to be worried about. A gun-type fission bomb is simple enough for a well-funded terrorist group to construct from scratch - if they can obtain enough enriched Uranium.
There are currently no commercial power reactors that use highly enriched uranium. A terrorist group that stole a trainload of fresh fuel for one of today's power reactors would be unable to make a bomb from it.
Fast spectrum reactors require a larger core inventory of fuel and higher concentrations of fissile material within the fuel. That makes fuel diversion more dangerous with fast reactors. Presumably that's why people interested in fast reactors are trying to improve their proliferation resistance, to bring it in line with what's considered acceptable today.
As a side note, purely technical measures cannot render reactor designs proliferation-proof against rogue governments that might repurpose reactors to make weapons. At best you get some warning from breach of anti-proliferation measures so other countries know when legal/diplomatic countermeasures become warranted.
> There are hundred of weaponizable reactors in not really good places of the world.
Usually, a reactor is considered a proliferation problem if it allows you to produce plutonium easily. Getting radioactive material isn't good enough to be a significant security risk, because dirty bombs are much more complicated than conventional explosives, for an impact that isn't significantly bigger.
So a reactor can be a risk if it lets you get plutonium easily (and, specifically, the Pu239 isotope). The other plutonium isotopes are not good weapon material, and so you want to be able to use a reactor that lets you produce material with as much pu239 as possible.
Depending on design, if you can get easy access to the nuclear fuel, you can filter it frequently to retrieve the pu239, before it has a chance to react with another neutron and become one of the bad Pu isotopes.
BWR and PWR reactors are bad for enrichment, because in order to access the fuel, you need to stop the reactor and depressurize the primary cooling circuit, which takes time. On the other hand, if you let the fuel spend a long time in the reactor, you end up with spent fuel that has lots of Pu240 and Pu241, which sucks.
Other types of reactor, like CANDU, RMBK or UNGG reactors let you access the fuel more easily, without shutting down the reactor. Therefore, it is easier and quieter to retrieve the fuel frequently and get the Pu239 before it has time to react again.
That is why some types of reactors are nicer to have if you want to build a bomb: they take less time and would raise less suspicion from other countries to collect the same amount of Pu239.
Currently, most commercial reactors in the world use BWR/PWR technology.
I think that sums up the gist of what it means to make a reactor less proliferation-friendly, and why it's important in order to make that technology more friendly to export.
There are hundred of weaponizable reactors in not really good places of the world. In case of the next big war, nobody will ask IAEA for permission to build the nuke.
As some the saying goes, the genie is long out of the bottle.