Yes, CIRCUMSTANCES is a Scrabble word!

Letter values in Scrabble US: C 3, I 1, R 1, C 3, U 1, M 3, S 1, T 1, A 1, N 1, C 3, E 1, S 1.

Is it a valid word?

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

your overall circumstances or condition in life (including everything that happens to you)
a person's financial situation (good or bad)
a condition that accompanies or influences some event or activity
the set of facts or circumstances that surround a situation or event
information that should be kept in mind when making a decision
formal ceremony about important occasions