Full Description 1.1 This specification covers uranium hexafluoride (UF6) intended for feeding to an enrichment plant. Included are specifications for UF6 derived from unirradiated natural uranium and UF6 derived from irradiated uranium that has been reprocessed and converted to UF6 for enrichment and subsequent reuse. The objectives of this specification are twofold: (1) To define the impurity and uranium isotope limits for Commercial Natural UF6 feedstock so that the corresponding enriched uranium is essentially equivalent to enriched uranium made entirely from virgin natural UF6; and (2) To define additional limits for Reprocessed UF 6 (or any mixture of Reprocessed UF6 and Commercial Natural UF6). For such UF6, special provisions may be needed to ensure that no extra hazard arises to the work force, process equipment, or the environment.1.2 The scope of this specification does not comprehensively cover all provisions for preventing criticality accidents or requirements for health and safety or for shipping. Observance of this specification does not relieve the user of the obligation to conform to all international, federal, state, and local regulations for processing, shipping, or in any other way using UF6 (see, for example, TID-7016, DP-532, ORNL-NUREG-CSD-6, and DOE O 474.1).1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.