Any science or engineering job issues?

[anon1943]

I am completing my master's degree in a sub-discipline of nuclear physics. After graduation it is likely that I will be seeking employment at various government and private nuclear facilities, what I mean by that, any facilities that utilizes ionizing radiation in one form or another. 

I'm slightly worried about taking a poly graph test because of my excessive drug use during my teen-years, from marijuana to acid I've done them all and I don't think I could pass any drug use questions.  I'm completely drug free and have been for over 10yrs.

So...  Does anyone know if a lie detector test is required for employment at a nuclear research facility/power plant, or other government-based scientific facilities?

Will a failed poly-graph test be accessible by industries in the private sector during the background check process?  If so I may try to avoid government all together.