The Current reactor is a Conventional reactor but without steam. Replace the current one with a Conventional steam powered reactor, and if you want Pure EU use the RITEG, which doesnt make that much power (10 eu/t per Quad Uranium?) but lasts alot longer. Also has no risk of Exploding, but does emit Radiation, hurting all things nearby.
IMO, both reactors should have a radioactivity effect, not because realism, but because HAYO. (I'm portraying my nuclear power plant, with a HAZMAT suit on a armor stand next to a sign "ALL employees must wear HAZMAT gear prior to entering reactor room). Tough RITEG should have a bit more... larger area of effect and/or stronger effects.
I also think that any reactor you build will be conventional by defaul, attack a cable onto it, and it automatically becomes a RITEG.
This is my suggestion on radioactivity:
-You will get small effects if you are holding nuclear cells without a full hazmat gear, or quantum or nano armor. Like hunger, nausea e.t.c. Temporary effects.
-Get into a room with a reactor without a Hazmat or quantum armor and you will get moderate effects, like withering, no health regeneration, e.t.c, however, if you stay too long next to a reactor, the effect becomes permanent. How can you heal yourself? build a decontamination chamber, supply it with EU and right click. You will enter it and see a progress bar. Once its is done, tadaaa. You are good to go.
-Nuclear Explosions have a massive amount of radiation, killing everything in its radius in a short time. You have to be extra fast not to die, and you will likelly get permanent effects.