“ It is the 'traditional rule' that interest on claims against the United States cannot be recovered in the absence of an express provision to the contrary in the relevant statute or contract. 28 U.S.C. (Supp. III) , § 2516 (a) , 28 U.S.C.A. § 2516 (a) . United States v. Thayer-West Point Hotel Co., 1947, 329 U.S. 585, 588, 67 S.Ct. 398, 399, 91 L.Ed. 521, and cases cited therein. This rule precludes an award of interest even though a statute should direct an award of 'just compensation' for a particular taking. United States v. ”

“ The only exception arises when the taking entitles the claimant to just compensation under the Fifth Amendment. Only in such cases does the award of compensation include interest. Seaboard Airline R. Co. ”