I do have to admit that the scenario that Marssim puts out there is, one; scary and, two; not uncommon. That being said, I'm not about to try to discuss someone else's decision to include/exclude personal bias based on outside romantic inputs. I'm just saying that if someone is important to you then their desires should have an influence on your life, because your decisions will have an impact on theirs. I didn't join the Navy until very late in life, so that I could stay with my girlfriend... I later married her and we've just celebrated our 10-year. I don't know what lucid's situation is, but I know that I would ask before tearing him a new one. (Side note: lucid, Marssim has made a very valid point in his example. Make sure it doesn't apply to you.)
War Eagle, sorry for the assumption. I extrapolated data from Marssim's references about you being the in-the-know guy for NR positions and your input shortly thereafter. My statement still stands about the initially posed question being a difficult one.
All said and told, lucid, make sure that you do a lot of research before making your decision. Getting into the nuclear industry is a great challenge, an excellent area for personal growth, and an outstanding financial choice for a stable and comfortable future. If your girlfriend is an integral part of your life, involve her in these decisions. My wife was not real thrilled about me joining the Navy, but when she saw how important it was to me she was very supportive. It may have taken close to ten years and life changing events, but once we agreed on the decision she was all I could ever need every time I needed her (and that was often).
Good luck and keep us posted.