Yes, SANCTUARY is a Scrabble word!

Letter values in Scrabble US: S 1, A 1, N 1, C 3, T 1, U 1, A 1, R 1, Y 4.

Is it a valid word?

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

a consecrated place where sacred objects are kept
a shelter from danger or hardship
area around the altar of a church for the clergy and choir; often enclosed by a lattice or railing