Cook shimp and cut into 1/4 pieces.

In a small bowl toss carrot with scallion greens, vinegar, and salt and pepper to taste.

Fill a small shallow baking pan or cake pan with warm water. Working with 4 sheets rice paper at a time, immerse them in water and let stand until very pliable, about 45 seconds. Carefully arrange soaked sheets in a single layer on paper towels to drain. Working with 1 soaked sheet at a time and keeping remaining sheets covered with dampened paper towels, put sheet on a clean dry work surface and arrange about 1 tablespoon coriander leaves in a horizontal line across bottom, leaving a 1-inch border on bottom edge and on each side. Top coriander with about 2 tablespoons shrimp pieces and top shrimp with about 1 tablespoon carrot mixture. Sprinkle about 1 tablespoon lettuce, about 1 tablespoon sprouts, and salt and pepper to taste over carrot mixture. Roll up filling tightly in sheet, folding in 2 sides of sheet to completely enclose filling, and continue rolling.

Make more spring rolls in same manner with remaining 3 soaked sheets. Transfer assembled rolls to a tray and cover with dampened paper towels. Repeat procedure with remaining 8 rice paper sheets and filling ingredients. Tightly cover tray with plastic wrap (keeping dampened paper towels directly on spring rolls). Spring rolls may be made 6 hours ahead and chilled.

Just before serving, with a serrated knife cut spring rolls in half diagonally. Arrange spring rolls on a platter and garnish with coriander sprigs. Serve spring rolls with peanut sauce.