Interfaces

Think of how many different modern devices now use Bluetooth connections and smartphone apps to control them. Extend that further, and the various controls and diagnostic displays in the plant all were built with the expectation that the maintenance techs will have their own Augmented Reality system that they can use to view the outputs and send commands back to the system.

The main control panels have visual displays for redundancy and the AI is of course monitoring everything as well so the plant can still be operated, but in order to perform detailed, specific maintenance, you need to have the interface augments that the system was built to work with.

The AI is smart enough to identify that, say, Pump AX-1 is operating at 72% capacity, but can't identify that it's because a compressor seal in it is wearing out. The AR interface would let a maintenance tech accessing the pump see its full technical specs, pull up the complete maintenance log for it including when all of the seals were last replaced, the expected life cycle of those seals, the replacement part numbers, etc. And even if the AI could identify that the compressor seal was failing, it wouldn't have the step-by-step instructions available for how to disassemble the pump and replace it.

Since the post-apocalyptic crew doesn't have those augs, they either have to replace broken components from an increasingly-depleted stock of spare parts, or figure out patch fixes, kludges, or workarounds that clear the error that the AI is reporting. So the post-apocalyptic operators are making duedo with bare-minimum fixes that are slowly eroding the safety margins and failsafes that the system was designed with.

Once someone is able to properly access the maintenance interfaces, they'll be able to begin the process of getting the reactor back up to spec, if it's still possible at that point.