In mixing bowl stir together the all-purpose flour, sugar, baking powder, salt, and baking soda.
Beat together the eggs, melted butter or margarine, milk, grated orange peel, and orange juice.
Stir the butter mixture into the flour mixture, stirring just till dry ingredients are moistened.
Fold in the blueberries and walnuts.
Pour batter into a greased 9x5x3-inch loaf pan.
Bake at 350° till golden brown, 60 to 70 minutes.
Remove from pan; cool.
Wrap in foil and store overnight before slicing.