There are authorized to be appropriated for assistance payments under this subchapter $520,665,600 for fiscal year 1993 and $542,533,555 for fiscal year 1994, of which such sums as may be necessary shall be available in each such fiscal year for use under section 12852(e) of this title. Any amount appropriated under this section shall be deposited in the Fund and shall remain available until expended, subject to the provisions of section 12858 1