Another thing you could do is watch any of Direwolf20's LP videos on youtube. He runs his own pack(s) and has a series for every version of MC his pack has been created for (1.7, 1.10 and probably 1.12 very soon). He has included Extreme Reactors (and it's ancestral mods) since it was first introduced.
Since his packs run mods that have very little modification (no changed recipes, etc) you can be sure that the builds are as close to the same as the original modders' intended them to be.
In addition, he does "Mod Spotlight" videos on most mods, although the Extreme Reactor vid might be a bit dated. He also was one of the first to automate reactors using Computercraft. [Edit] He also has his "computer" code available for download and mentions how to get it while setting up the automation.
All of his LPs and Spotlights are collected in playlists on Youtube. The LPs also have World Downloads every 10 episodes or so so you can get and run in-progress worlds identical to those in the videos to play along if you want.