I am trying to get the Minor Operative accolade. Where is the best place in game, other than the Azura mission (which I have already completed) to find and defeat Orion pirates?

What you can do is get a mission that spawns orions, do80% of it, then leave and drop the mission/retake it. I believe "The Kuvagh'Magh' has a bunch of orions.

Yeah, the one on Regulus even has infinitely respawning waves of them. I wish I had thought of that before I did that mission, heh.