Background research is crucial to developing any new project or mod package. Here are some tips specifically tailored to electrical engineers . . . .
The initial background research period is where you do your research about the system you are going to be modifying and the different interfaces new equipment will impact. By interfaces, I mean physical connections: incoming cables, outgoing cables, new cables, conduit connections, panel boxes, the place where new equipment will be mounted, and so on.
You need to accumulate the existing single-line drawings, schematic diagrams, wiring drawings, and raceway or conduit drawings. You need to find calculations that track the existing power load consumed by the existing equipment. Look for plant design criteria that might contain specific instructions for how to do things like compute voltage drop, cable sizing, and breaker sizing, as well as how to number new equipment, cables, and drawings.
Another thing you should do is figure out how the existing equipment works and what its purpose is within the overall system it’s a part of. Read through the plant’s UFSAR and TS Bases, as well as any other design basis documents that compile technical explanations, to acquire any specific information that may be relevant to understanding how the system and components presently work. You need to understand what existing safety-related functions, if any, are performed by the existing equipment so you can get an idea what features and functionality the new equipment will have to replace.
If you are adding new features or functionality, study how that functionality will interact with the existing SSCs to identify any unexpected pitfalls in actual operation. You don’t want to be like the Weapon X scientists who recognized the usefulness of fusing an indestructible metal to Wolverine’s skeleton to turn him into an invincible assassin, only to overlook the possibility that he could go on a murderous rampage and destroy the whole program.