there are 99 nuclear reactors operating in the US, producing about 100,000mw. So about 1000mw/ea.

Many of the plants in the US have more than one reactor.. but you can see on this page, plant capacity/units is about 1gw/ea [edit: corrected, thanks], and many of the single reactor plants are about that size also: https://en.wikipedia.org/wiki/List_of_the_largest_nuclear_po...

Note, that page has the largest plants.. about ~45. There are only 61 in the US. So there are a few smaller ones not in the list. If you built a 1100mw reactor, it would be ~#42 largest plant.

Isn’t this not about size of energy produced but rather the physical size of the reactor?

*1 GW each.

A small reactor is under a few hundred megawatts. A micro reactor is on the order of tens of megawatts. It's quite hard to make economic reactors below that.

Some Russian satellites went into space with two to a whopping six kilowatt reactors (https://en.wikipedia.org/wiki/US-A). The Americans in contrast only got a 500 watt reactor into the sky, and it failed after 43 days (https://en.wikipedia.org/wiki/SNAP-10A).

Yes but when you aren't allowed to use highly-enriched (weapons-grade) uranium it's a different story.

And space is a much different story for economics. Out there, fully enriching your fuel probably makes sense because weight is so expensive. My comment was limited to terrestrial reactors.

1100 MW is big enough that you would need to connect to the high voltage transmission network. This will require you to build the station close to an existing line with capacity, or spend millions on your own cable.