Preheat the oven to 350 degrees F (175 degrees C). Set a 9x13-inch casserole dish aside.

Combine chicken breasts, celery, 1/2 teaspoon salt, 1/8 teaspoon black pepper, and enough water to cover in a large saucepan; bring to a boil. Cover, reduce heat to medium low; simmer for 35 minutes. Drain, reserving 1 cup liquid. Cool chicken, remove meat from bones, and cut into bite-size pieces; discard bones.

Combine soup, reserved 1 cup cooking liquid, sour cream, celery salt, garlic powder, and onion powder; season with salt and black pepper. Stir in cooked chicken and rice; spoon into casserole dish.

Shake crushed crackers and melted butter together in a resealable plastic bag; sprinkle over casserole.

Bake in the preheated oven for 30 to 35 minutes.