Cost is a larger issue than proliferation. Civilian nuclear reactors care a lot more about fuel costs than military reactors do and highly enriched uranium just costs more.

Isn't weapon's grade uranium at 85%? I know that western powers got really worried at Iran past 19.75%. But, I still doubt it's that heavy for energy applications, even if military.

You are mistaken. US naval reactors run on around 95% enriched uranium. There's a desire to switch to lower enrichment fuels, but it meets a lot of competing concerns, such as state of the art naval reactors can be fuel'd just once for a ~40 year lifetime. Basically, military naval reactors are not a pathway to economic civilian reactors because the military has different concerns and less price sensitivity vs those concerns.

>95% Jesus effin Christ almighty

U for a nuke mounted on a missile needs to be heavily enriched. On a semi trailer, not so much.

What danger is there with proliferation? Does it really matter when the US has thousands of nuclear weapons?

Obviously a very US-oriented perspective, but: yes, to the extent that the US has historically attempted at least sometimes to be a global police power, they're significantly constrained when the country they're trying to police has nuclear weapons. The US response to Russia invading Ukraine has been fundamentally different in kind from, say, Iraq invading Kuwait, in which Iraqi forces were pushed back to the border in a matter of days. There are lots of reasons for this (much greater asymmetry in conventional military forces, etc.), but at least in part this is because of US concerns that direct conflict with Russia would escalate to nuclear war. Similarly, can already start to see how US posture towards North Korea is starting to change and will likely continue to do so as a result of their nuclear advancement.

Sorry this article is about US regulators approving the use of reactors in the US, right? That’s why I wrote in a US centric way.

Why does it matter that the US has more nuclear reactors that could potentially become weapons if they already a massive arsenal of nuclear weapons?

Yeah I never quite got this. We can have Putin say “you’d better let me kill whoever I want or I’ll destroy the entire world”, but we can’t have power plants.

Sure, terrorists will rummage around these and steal the fuel rods. Then they somehow figure out how to make a thermonuclear weapon.

"Standard LWR fuel in 17 x 17 configuration, each assembly 2 meters (~ 6 ft.) in length; up to 24-month refueling cycle with fuel enriched at less than 5 percent"

Proliferation among nations is also a concern not just terrorists.

Frankly, I think the most dangerous countries have nuclear weapons already. I mean of course those countries prone to starting imperialistic wars, threatening their neighbors, apartheid, etc.

I would be rather concerned if Iran gained nuclear weapons. They have recently had both overt and covert wars of aggression and have threatened their neighbors etc. But they have also had a recent insurgency demonstrating instability.

But on the plus side, North Korea already has them.

It seems China and Russia are actively building SMRs. [0] I'd be a pity if the west do not get serious at least about exploring the opportunity to test some of the designs being made.

https://en.wikipedia.org/wiki/Small_modular_reactor#List_of_...