I am an Instructor Trainer -- I teach the Operations Instructors and keep them qualified to teach. Your roadblocks would indeed be many and formidable, the most severe of which would likely be gaining the respect of your peers and trainees. They have all gone through very rigorous training and a lot of hard work to get where they are (I am not saying you haven't, but it is totally unrelated experience.) The amount and intensity of training that goes into making an Operator is astounding. Without that experience you are not likely to do well as an instructor. On top of that you are severely limited by not having an operators license yourself. You are limited in the classes that you can teach without a license or SRO Certificate. As an instructor you will also be required to attend the training that your trainees do (i.e. those classes you do not teach) and pass any related tests to maintain your technical skills. Very difficult without the background.
There are Engineering Instructor positions in Nuclear Plants as well. Perhaps that is where you should be looking if you really want to enter the nuclear arena. You would still need to beef up your nuclear knowledge, but it would be much less of a stretch.
Good luck and keep us informed.