Greetings!
Does anyone know of a source/site that accepts plays or one acts for publication? Does duotrope have access to these markets?
I don't, but you could email someone either in the Communications department or the English department of a local university. I'd try both, since Communications usually has the students interested in drama and scriptwriting, and English would have writing intensive majors as well. Find the department heads on the college website. They would be able to either tell you or to point you in the direction of someone who might know. Here's the University of Texas Communications department, and the English department. A good place to start.
duotrope doesn't.
Playscripts publishes scripts, but they have to first be produced by a professional company.
I suggest you submit your plays in competitions.