LEGO Reactor Unit
This compact reactor is designed to produce an enormous, yet safe, amount of energy within a small housing unit. This model is specifically built for a large nomad-class fortress, such as the Iceberg Outpost, which is a military base intended for mobile relocation.
This small unit can succumb to an unstable meltdown if left unmonitored. To combat this potential demise, various failsafes are implemented, such as breakers, temperature regulators, exhausts, energy dampers, and cooling units.
Within the reactor unit lies two removable energy cores with enough power to operate for years. These powerful cores are, for the most part, incredibly stable, but in the wrong hands they can be repurposed into makeshift bombs.
The energy cores are housed within the reactor's chamber, and they can only be extracted by a specialized gear system that extends the chamber outward. Here is a video that shows the entire process: