1.1 ,This specification covers nuclear grade uranium hexafluoride (UF₆) that either has been processed through an enrichment plant or has been produced by the blending of Highly Enriched Uranium with other uranium to obtain uranium of any , ²³⁵U concentration below 5 ,% and that is intended for fuel fabrication. The objectives of this specification are twofold: (1) to define the impurity and uranium isotope limits for Enriched Commercial Grade UF₆ so that, with respect to fuel design and manufacture, it is essentially equivalent to enriched uranium made from natural UF₆, and (2) to define limits for Enriched Reprocessed UF₆ to be expected if Reprocessed UF₆ is to be enriched without dilution with Commercial Natural UF₆. For such UF₆, special provisions, not defined herein, may be needed to ensure fuel performance and to protect the work force, process equipment, and the environment.