If you are going to be interning at NIH (congratulations btw, even if you have no funding because it can be an excellent feather in your cap), Bethesda is the place to live.  It is little expensive.  But check Craigslist and you might find a reasonable short term accomodation.  You might want to choose a place near the metro station so that you can go around.  Parking is a bitch, so better if you do not have a car.  There are quite a few Nepali households in the area, you just have to ask around.