Be aware that the Naval Research Lab is one of the worst parts of the city. If he/she has never lived in a big city, I wouldn't recommend it. There's a bus that connect the Naval Research Lab to the Anacostia Metro that might be safe only because it doesn't seem to stop in the residential areas:
https://www.wmata.com/bus/timetables/dc/a4-w5.pdf. If he/she has a car, I highly recommend that they bring it and drive to/from work.
We need a budget to recommend places too. Somewhere along the Green Line would probably be your best bet like Shaw, Petworth, Columbia Heights, etc.