Yes, CURVATURE is a Scrabble word!

Letter values in Scrabble US: C 3, U 1, R 1, V 4, A 1, T 1, U 1, R 1, E 1.

Is it a valid word?

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

(medicine) a curving or bending; often abnormal
the rate of change (at a point) of the angle between a curve and a tangent to the curve
the property possessed by the curving of a line or surface