Yes, DECLARATIONS is a Scrabble word!

Letter values in Scrabble US: D 2, E 1, C 3, L 1, A 1, R 1, A 1, T 1, I 1, O 1, N 1, S 1.

Is it a valid word?

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

a statement that is emphatic and explicit (spoken or written)
(law) unsworn statement that can be admitted in evidence in a legal transaction
a statement of taxable goods or of dutiable properties
(contract bridge) the highest bid becomes the contract setting the number of tricks that the bidder must make
a formal public statement
a formal expression by a meeting; agreed to by a vote