(a) Use as livestock feed and for distillation of alcohol. No payment shall be allowed or made under section 6418 (a) unless within 2 years after the date the right to such payment has accrued a claim therefor is filed by the person entitled thereto. Such right accrues as of the date the manufactured sugar, or article manufactured therefrom, is used for a purpose for which payment is allowable under section 6418(a).

(b) Exportation. No payment shall be allowed or made under section 6418 (b) unless within 2 years after the date the right to such payment has accrued a claim therefor is filed by the person entitled thereto. Such right accrues as of the date the articles are exported.