Yes, SOMERSETS is a Scrabble word!

Letter values in Scrabble US: S 1, O 1, M 3, E 1, R 1, S 1, E 1, T 1, S 1.

Is it a valid word?

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

a county in southwestern England on the Bristol Channel
an acrobatic feat in which the feet roll over the head (either forward or backward) and return