Can a person work 2 separate positions w/in the same company without additional hours being considered OT?

Generally speaking - no.  If both positions are with the same company, then you have to be paid overtime when you work over 40 hours per week per the Fair Labor Standards Act (FLSA).  Your Human Resources contact will be able to tell you more and whether any unusual exceptions exist for your situation.  Note: If your pay is different for each position, calculating that overtime may require weighting the averages of the two.  So, check the amount of your pay to make sure you're being compensated properly.