Yes, ROTARIES is a Scrabble word!

Letter values in Scrabble US: R 1, O 1, T 1, A 1, R 1, I 1, E 1, S 1.

Is it a valid word?

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

a road junction at which traffic streams circularly around a central island
electrical converter consisting of a synchronous machine that converts alternating to direct current or vice versa

Also: traffic circle, synchronous converter, rotary converter.