One interview with a panel.
I had three two of which were nurse managers and the third for me was the director of the program. (Friends of mine had a different panel) You interview alone. When you come in to the HR office there are several applicants and they bring you back one at a time (I went to the 7th floor immediately but a friend of mine waited an hour-ish)
The questions while I don't remember specifics were not difficult. Straight forward. They did a wonderful job at keeping my stress level down.