Piece Word

WITH the help of the Across clues only, can you fit the pieces into their correct positions in the grid?

ACROSS 1 Shell creature that clings to rocks 2 Avoided, dodged 3 No longer acceptable or practical 4 Refined in manner 5 More grouchy 6 Jettison 7 Store up 8 Person presiding at an inquest 9 Mountain range 10 Catastrophic 11 Film device 12 Seized