Unsure of the cause (presumably a mod conflict?), non-recoverable error when placing an ejector hatch on a nuclear plant:

Error while running event RenaiTransportation::on_nth_tick(3)
__RenaiTransportation__/control.lua:80: attempt to perform arithmetic on field 'electric_buffer_size' (a nil value)
stack traceback:
__RenaiTransportation__/control.lua:80: in function
<__RenaiTransportation__/control.lua:75>

Found it, it's this mod it conflicts with:
https://mods.factorio.com/mod/InsertersDontNeedPower

That's weird, I can see why that would be a problem but when I try it with that mod it works just fine.

Just in case though I added a check for inserters that have 0 buffer size so it should't happen in the future.

Yeah, it appears it was actually this mod (https://mods.factorio.com/mod/bobinserters-tweak) that makes no mention of altering the power demand.