You could always install the 100,000 small reactors at 100 large sites.

Are there any micro-reactor designs that use non-enriched or minimally enriched uranium? My understanding is that natural uranium isn't really that dangerous, even in a dirty bomb, and then in terms of proliferation it already isn't that hard to get it.

Yeah. Uranium for sale, no permits: https://unitednuclear.com/index.php?main_page=product_info&c...

Most reactors use somewhere in the range of 3-5% U235 (compared to .7% naturally). That by itself won't let you make a bomb, but it gets you about 1/8th of the way to 20% which is about where a bomb is possible.

I assume the risk is that a bad actor could make a dirty bomb from the uranium. If that's the case, how does the risk of that compare to the risk of other attacks against our water supplies, pipelines, bridges, or even poison gas attacks?

How do you compare the deaths from a distributed reactor network to the deaths from additional global warming?

As others pointed out - just because you have lots of micro reactors, they all don’t have to be in individual locations.

And there are far more easily obtainable things than uranium if you want to construct a dirty bomb. Another fantastic anti-nuke red herring.

The 100,000 smaller reactors can still be put in the same place as the 100 giant reactors to make inspection and monitoring easier. The modular design makes incremental capacity upgrades easier, makes maintenance and repair easy, and helps to put more testing and QA on the modular design. Just think of it as 100 locations where you can either have 1 giant reactor each or up to 1000 modular micro-reactors.