Yes, OCCLUSIVE is a Scrabble word!

Letter values in Scrabble US: O 1, C 3, C 3, L 1, U 1, S 1, I 1, V 4, E 1.

Is it a valid word?

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

a consonant produced by stopping the flow of air at some point and suddenly releasing it

Also: stop consonant, plosive consonant, plosive speech sound.