Yes, RELIEFS is a Scrabble word!

Letter values in Scrabble US: R 1, E 1, L 1, I 1, E 1, F 4, S 1.

Is it a valid word?

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

the feeling that comes when something burdensome is removed or reduced
the condition of being comfortable or relieved (especially after being relieved of distress)
(law) redress awarded by a court
someone who takes the place of another (as when things get dangerous or difficult)
assistance in time of difficulty
a pause for relaxation
a change for the better
aid for the aged or indigent or handicapped
the act of reducing something unpleasant (as pain or annoyance)
sculpture consisting of shapes carved on a surface so as to stand out from the surrounding background
the act of freeing a city or town that has been besieged

Also: stand-in, backup man, fill-in, rest period, sculptural relief.