If the tax imposed by Title IX of the Social Security Act or any amendments thereto, or any other federal tax against which contributions under this chapter may be credited for any cause becomes inoperative, the provisions of this chapter, by virtue of that fact, likewise become inoperative, and any unobligated money in the Unemployment Compensation Fund or returned by the Secretary of the Treasury because the Social Security Act is inoperative must be refunded to the contributors proportionately to their unexpended contributions, under the regulations of the Administrator.