Yes, SOUDAN is a Scrabble word!

Letter values in Scrabble US: S 1, O 1, U 1, D 2, A 1, N 1.

Is it a valid word?

SOUDAN is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a republic in northeastern Africa on the Red Sea; achieved independence from Egypt and the United Kingdom in 1956
a region of northern Africa to the south of the Sahara and Libyan deserts; extends from the Atlantic to the Red Sea

Also: republic of the sudan.

Not playable in Scrabble US: SUDAN.