Yes, NAPAS is a Scrabble word!

Letter values in Scrabble US: N 1, A 1, P 3, A 1, S 1.

Is it a valid word?

NAPAS is a valid word in the official Scrabble dictionary (US) and the UK Scrabble Dictionary, but not in Words with Friends (ENABLE).

plant with an elongated head of broad stalked leaves resembling celery; used as a vegetable in east Asia

Also: chinese cabbage, celery cabbage, pe-tsai, brassica rapa pekinensis.