Notwithstanding section
8411
(b)(3) of title
5, except to the extent that an eligible employee may be otherwise compensated (including the provision of retirement benefits in accordance with the memorandum of understanding) for the period of service as an employee of the Tennessee Valley Authority, that period of service shall be treated as a period of service as an employee of the U.S. Department of Agriculture for all purposes relating to the Federal employment of the eligible employee.