What do all settlements need? Lots of power! While solar panels and wind turbines are all very well, you can't beat a decent reactor, and here is mine.
As with my machinery tower, this is built from plaster blocks from a Hirst Arts mould. I've used curving corridor wall sections from the starship wall mould #301 for the main reactor casing, with a small statue plinth from the gothic dungeon accessories mould #41 for the end caps. For the cable run covers between the reactors I've used some tiny curved blocks from the Cargo Bay Accessory Mould # 302. Here you can see a few NAC Marines and a technician from GZG to give a sense of scale. The Rebel Alliance reactor destroyed by the AT-AT assault on Hoth was the inspiration for this piece of scenery. I haven't decided whether it's going to have a fence or wall around it, or remain a standalone item that can be dropped inside a larger building.
Some of the outer colonies have rather battered old reactors. You can see that this one is rather rusty with the odd hole in the outer casing, but the healthy blue glow shows that it's still working just fine. The technician regularly checks it, and the armoured inner reactor vessel is in very good condition. Mayor Hokum (GZG colonist on the left with a headswap) wouldn't be standing this close to it if there was any chance getting irradiated!