Heat oven to 375°F. In 10-inch nonstick skillet, cook beef, onions and celery over medium heat, stirring frequently, until beef is thoroughly cooked; drain.
Stir in both soups, the green beans, garlic powder and pepper; spoon into ungreased 2-quart casserole. Top with potato nuggets.
Bake uncovered 40 to 50 minutes or until mixture is bubbly and potato nuggets are golden brown.