6 servings (serving size: about 1 2/3 cups)
Cook pasta according to package directions, omitting salt and fat; drain. Cool completely.
Combine orange juice and the next 7 ingredients (orange juice through rice vinegar) in a large bowl, stirring with a whisk to combine. Add pasta, chicken, grapes, celery, red onion, walnuts, chives, and parsley; toss gently to combine.