Yes, PATERNOSTER is a Scrabble word!

Letter values in Scrabble US: P 3, A 1, T 1, E 1, R 1, N 1, O 1, S 1, T 1, E 1, R 1.

Is it a valid word?

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

(Roman Catholic Church) the Lord's Prayer in Latin; translates as `our father'
a type of lift having a chain of open compartments that move continually in an endless loop so that (agile) passengers can step on or off at each floor