Chernobyl and Fukushima I will grant (especially Chernobyl!) but Three Mile Island has a no-go zone that's far smaller than most people think. And it's only sort of no-go at that.

> which could wipe out our grid, leading to nuclear leaks worldwide

Sorry, but citation needed for the causal mechanism via which the grid going down would lead to "nuclear leaks".

> Pushing water past the core means pumps that are generally run by electricity. What happens when a reactor gets disconnected from the grid? There are emergency diesel generators. You also have a battery system to keep instruments running, but that can also provide power to safety systems [which prevent a meltdown by cooling the reactor core]. It's all meant to provide defense in depth. First you rely on the grid. If the grid is no longer available, you use diesel generators. If there is an issue with the diesels, you have a battery backup. And the batteries usually last long enough for you to get the diesels going. [1]

All I'm saying is that we have a very short term understanding of cosmic events and extreme space weather events [2] and maybe a good percentage of nuclear power plants could withstain these types of events, but I don't see it as a viable long term option.

[1] https://www.scientificamerican.com/article/how-to-cool-a-nuc...

[2]https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/201...

I agree that this is something we should be keeping in mind as we build new reactors. And people have in fact kept it in mind. Modern reactor designs use passive cooling systems that don't need power to operate properly.

The single best thing we could do for nuclear safety, including from extreme space weather effects, is replace decades-old plants with modern ones. Unfortunately, people tend to react to that with "we shouldn't build any new nuclear plants, even if we're replacing old and less safe ones".

Just to put this in perspective, the first ever commercial nuclear plant was opened in 1956. Fukushima construction began in 1967, finished in 1971, 40 years before the meltdown. We've learned a good bit about safety in reactor design in the 50+ years that have passed since Fukushima was designed...

So, yeah.

> Due to the prolonged period of stagnation in the construction of new reactors and the continued (but declining) popularity of Generation II/II+ designs in new construction, relatively few third generation reactors have been built. Generation IV designs are still in development as of 2017, and are not expected to start entering commercial operation until 2020–2030.[1]

[0]: http://www.world-nuclear.org/information-library/nuclear-fue...

[1]: https://en.wikipedia.org/wiki/Nuclear_reactor#Reactor_types

I don’t understand how nuclear leaks could be a result of grid failure.

Also, I read recently that CME could cause DC charge to occur on very long power lines, but that modern systems can handle this. There was a HN thread about this couple days ago, can anyone find it?