US Navy Nuclear Engineer interview questions

Invited to DC to interview. Had technical interviews with three SESs and a final interview with the Director. The technical interviews were 45 minutes and largely focused on calculus and physics problems, but there was also a good amount of time spent in discussion. There is a fit process going on throughout the whole interview.

Meet a recruiter on a college campus, had a quick 1 on 1 interview. After I sent them my transcripts, we set up an onsite interview. Gov't paid for everything. Onsite interview was 4 other candidates and we mostly just walking around the shipyard, talking to random people. Had a 1 on 1 with the 'boss-to-be' and a group interview with people who would be my coworkers. All candidates had to then reapply online and go through usajobs.gov . After about 3 months, I got a phone call asking if I was still interested.