If at any time Tit. IX of the Social Security Act, as amended, shall be amended or repealed by Congress or held unconstitutional by the supreme court of the United States, with the result that no portion of the contributions required under this chapter may be credited against the tax imposed by said Tit. IX, in any such event the operation of the provisions of this chapter requiring the payment of contributions and benefits shall immediately cease, the department shall thereupon requisition from the unemployment trust fund all moneys therein standing to its credit, and such moneys, together with any other moneys in the unemployment compensation fund shall be refunded, without interest and under regulations prescribed by the department, to each employer by whom contributions have been paid, proportionately to the employer’s pro rata share of the total contributions paid under this chapter. Any interest or earnings of the fund shall be available to the department to pay for the costs of making such refunds. When the department shall have executed the duties prescribed in this section and performed such other acts as are incidental to the termination of its duties under this chapter, the provisions of this chapter, in their entirety, shall cease to be operative.