1Heat oven to 350°F. Pierce sweet potatoes with fork to allow steam to escape. Bake 55 to 60 minutes or until tender. Cool 10 minutes.
2Meanwhile, remove fat from pork chops. Place pork in ungreased rectangular pan, 13x9x2 inches. Mix salt, paprika, garlic powder and pepper; sprinkle half of the salt mixture over pork. Turn pork; sprinkle with remaining salt mixture. Pour 1/2 cup orange juice into pan; set aside.
3Cut each sweet potato lengthwise in half. Scoop out pulp, leaving 1/4-inch shell. Mash pulp until no lumps remain. Beat in 2 tablespoons orange juice until light and fluffy. Stir in apple, onion and celery. Fill shells with pulp mixture.
4Move pork to one end of pan; place sweet potatoes in other end of pan. Bake uncovered about 35 minutes or until sweet potatoes are hot and pork is slightly pink in center.