【国外标准】 Standard Practice for Bulk Sampling of Liquid Uranium Hexafluoride

5.1 Uranium hexafluoride is normally produced and handled in large (typically 1- to 20-ton) quantities and must, therefore, be characterized by reference to representative samples. The quantities involved, physical properties, chemical reactivity, and hazardous nature of UF6 are such that for representative sampling, specially designed equipment must be used and operated in accordance with the most carefully controlled and stringent procedures. This practice indicates appropriate principles, equipment, and procedures currently in use for bulk sampling of liquid UF6. It is used by UF6 converters, enrichers, and fuel fabricators to review the effectiveness of existing procedures or as a guide to the design of equipment and procedures for future use.5.2 It is emphasized that this practice is not meant to address conventional or nuclear criticality safety issues.1.1 This practice covers methods for withdrawing representative samples of liquid uranium hexafluoride (UF6) from bulk quantities of the material. Such samples are then prepared for further analytical testing in accordance with Practices C1689 and C1346. Multiple different methods are used for determining compliance with the applicable commercial specification, for example Specifications C787 and C996. Methods used for compliance to each of these standards can be found in the Referenced Documents section of each respective specification.1.2 It is assumed that the bulk liquid UF6 being sampled comprises a single quality and quantity of material. This practice does not address any special additional arrangements that might be required for taking proportional or composite samples. When the sampled bulk material is being added to UF6 residues already in a container (“heels recycle”) additional arrangements are required to avoid cross contamination of the bulk UF6, these are addressed in Specifications C787 and C996.1.3 The number of samples to be taken, their nominal sample weight, and their disposition shall be agreed upon between the parties.1.4 The scope of this practice does not include provisions for preventing criticality incidents.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.