Yes, COPPERS is a Scrabble word!

Letter values in Scrabble US: C 3, O 1, P 3, P 3, E 1, R 1, S 1.

Is it a valid word?

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

a ductile malleable reddish-brown corrosion-resistant diamagnetic metallic element; occurs in various minerals but is the only metal that occurs abundantly in large masses; used as an electrical and thermal conductor
a copper penny
uncomplimentary terms for a policeman
a reddish-brown color resembling the color of polished copper
any of various small butterflies of the family Lycaenidae having coppery wings

Also: atomic number 29, copper color.

Not playable in Scrabble US: CU.