Another interesting board 1 hand.

North will pass.

East will open 1♦ 

South will pass.

West has a choice between 2NT or 2♣? Here is a good EBU summary document on Acol bidding.

Some people may be worried about the 3 ♠ s, 10 high, but 2NT shows the balanced hand shape 5332 and 10-12 HCPs.. 

A bigger worrier is that the hand is stronger than 12HCPs, it has good intermediates 10 and 9s. Also the good 5 card ♣ suit. The Kaplan hand evaluator shows it is worth 12.75HCPs, so probably 2♣ could be better and see partners response.

Over West's 2NT bid East will review his hand to see if he should raise to 3NT. In teams scoring game is crucial and would say 3NT is the bid. In duplicate how would you evaluate your bid. East has a good source of tricks in ♦ s opposite partner's probably 2+♦ s and East's stops and entries in the majors he should raise 2NT to 3NT. East's hand is also far stronger than his 13HCPs, The above Kaplan hand evaluator shows it is worth 15.5HCPs due to the 10,9s, finessable positions and the 6card suit.

Over West's 2♣ East could evaluate his hand as 15-16HCPs and bid 2NT which west will easily raise to 3NT. Or East could bid 2♦ 

Over East bidding 2♦ West could bid 2NT or 3NT. Because his hand is so strong it is probably better to bid 3NT. Though if West bids 2NT (10-12) East should raise this to 3NT.

All bidding should probably lead to 3NT. E/W make 3NT +1 with correct play.