Marinated Shrimp with Champagne Beurre Blanc

Name: Marinated Shrimp with Champagne Beurre Blanc
Ingredients: 2 cups Champagne or other dry sparkling wine; 1/3 cup finely chopped shallots; 2 tablespoons Champagne vinegar or other white wine vinegar; 1/4 teaspoon whole black peppercorns; 1 cup Champagne or other dry sparkling wine; 1/4 cup extra-virgin olive oil; 3 tablespoons minced shallots; 1/2 teaspoon freshly ground black pepper; 24 extra-large uncooked shrimp (about 2 pounds), peeled with tail left intact, deveined; 1 tablespoon minced fresh chives; 1 tablespoon minced fresh tarragon; 1 tablespoon minced fresh parsley; Nonstick vegetable oil spray; 1 cup (2 sticks) chilled unsalted butter, cut into 16 pieces