Florida Orange Poached Scallops with Florida Grapefruit Yuzu Sauce and Shichimi Spice

2 cups Florida orange juice
2 cups white wine
¼ cup rice vinegar
¼ cup lemon juice
¼ cup carrot, diced into ¾-inch cubes
¼ cup onion, diced into ¾-inch cubes
¼ cup celery, diced into ¾-inch cubes
2 tablespoons fresh gingerroot
1 teaspoon peppercorns
1 bay leaf
6 large scallops, cleaned
1 cup Florida grapefruit, segmented
4 scallop shells (optional)*
Sea salt to taste
Shichimi spice to taste**

Grapefruit Yuzu Sauce:
¾ cup Florida grapefruit juice
¾ cup white wine
1 tablespoon rice vinegar
2 teaspoons grenadine
2 tablespoons shallots, chopped
1 teaspoon Yuzu juice
3 tablespoons butter
Salt to taste