SMRs - Factorio Mods

SMRs

Small modular nuclear reactors designed to be deployed off-grid at remote sites. SMRs are manufactured as sealed units with a fixed energy capacity, including both fuel and generator components. This means they can be quickly setup anywhere but once depleted must be returned to base for refurbishment.

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

https://forums.factorio.com/viewtopic.php?f=190&t=74435

Pros

Small footprint, quick and easy to deploy in the wilderness
High energy density compared to solar or accumulators

Cons

Limited energy supply rates
Uranium fuel cells for life span required in advance
Eventually becomes depleted and must be refurbished
Efficiency penalty compared to running power lines from main grid

And since this is Factorio, Cons are just another person's Pros :-)

Other notes

5MW 10GJ / 25MW 100GJ / 50MW 500GJ
Supply priority is tertiary, same as accumulators, so an SMR on the main electricty grid is like a high-capacity accumulator that can't recharge.
SMRs retain fuel level if picked up and moved. Fuel reserve is visible as a health bar when in an inventory.
Current fuel level can be read by the circuit network, like an accumulator.