People tend to check in during these times:
Outdoor parking is terribly priced for government workers. $4 per 2 hours. You'd have to use parkmobile and be billed 4 times in a day by credit card or get towed. Better to hotel park for $30.
There is a small museum in the first floor open to the public. It covers the entire timeline of nuclear power and the Manhattan Project, as well as the DOEs other research.
Basement of South Bldg still has $1 can soda vending machines. The rest of DOE is $1.75 16oz bottles.
Dunkin Donuts in the basement
Best food of Depts on independence ave