Fill a large pot 3/4 with water and bring to a boil. Add orzo and dill sprigs and cook until orzo is al dente (about 10 minutes), or according to package directions. Remove 1 cup cooking water. Drain orzo. Remove and discard dill sprigs.
Coat a wok with cooking spray, add the oil, and place over medium-high heat. When hot, add carrot and stir-fry for 1 minute.
Add scallops, orzo and reserved cooking water and cook, stirring frequently, until most of the liquid has been evaporated and scallops are opaque throughout (4 - 5 minutes).
Stir in pepper, chopped dill, lime juice, lime zest, and garlic.