Pro Film and Lab in Washington, DC?

I'm planning to take a trip to Washington, DC, soon. Although I have
a Nikon digital SLR, I still enjoy shooting a lot of black & white film
too. If possible, I'd like to fly to DC, go to a pro camera store and
pick up some Fujifilm Neopan film. Prior to leaving town, I'd like to
take it to a lab and have the film processed in a day or less. I'd
like to hear of a lab/store in DC where I can get true black & white
film and have it processed. If I can't identify one in advance, I
guess I'll drive to DC instead of flying in order to avoid sending film
through an airport x-ray machine. Thanks in advance.

Bob