In a very large mixing bowl allow egg whites to stand at room temperature for 30 minutes. Meanwhile, sift the 1 1/2 cups powdered sugar and the flour together 3 times. Set aside.
Add cream of tartar and vanilla to egg whites. Beat with an electric mixer on medium speed until soft peaks form (tips curl). Gradually add granulated sugar, about 2 tablespoons at a time, beating until stiff peaks form (tips stand straight).
Sift one-fourth of the powdered sugar mixture over beaten egg whites; fold in gently. Repeat, folding in the remaining powdered sugar mixture by fourths. Gently fold in freeze-dried blueberries and orange peel. Pour into an ungreased 10-inch tube pan. Gently cut through batter to remove air pockets.
Bake cake on the lowest rack in a 350 degrees oven for 40 to 45 minutes or until top springs back when lightly touched. Immediately invert cake in pan; cool completely in pan. Loosen cake from pan; remove cake.
In a small bowl combine the 1 cup powdered sugar and 3 teaspoons of the orange juice concentrate. Stir in enough of the remaining orange juice concentrate, 1 teaspoon at a time, to reach a drizzling consistency. Drizzle over cooled cake.
Look for freeze-dried blueberries in the produce section of the supermarket. Do not substitute dried blueberries.