I had an account in a bank in Nepal with some money. Now I ama US citizen. Will i be able to withdraw my money from the bank when i visit Nepal?

you cant...because you need citizenship of nepal to activate, withdraw account...
but there may be some way around ..good luck

Of course you can, just go and tell them you need to close your account. They don't ask for your citizenship, nobody carries citizenship card in Nepal. You are the living body that matches the photo they have and you can sign in front of them for signature match.

Nada!
Most of the bank used to open an account with minimum 10 buck, as new foreign bank came they started with 1000 buck.
As account goes inactive as well raised the minimum balance and started charging various charges evan for your bank balance statement.
Bottom line is if your balance was less than the bank required minimum balance , it may be gone all by now !!!