Remove side-muscle from scallops and slice crosswise with a very sharp knife into 1/4-inch thick rounds.
In a small bowl, whisk together orange juice, lemon juice and zest and olive oil until emulsified. Pour onto a serving platter or divide among 4 individual plates.
Arrange sliced scallops over dressing and garnish with pistachios, chives, red pepper flakes and salt. Serve.