【国外标准】 Standard Practice for Preparation of Plutonium Materials by Pyrohydrolysis for Determination of Fluoride, Chloride, or Both

5.1 This practice provides a means of collecting fluoride and chloride from plutonium test materials for analysis by ISE or IC. The results can be used to determine whether the material meets the requirements of Specifications C757 or C833, or other specification agreed by a supplier and customer, for fluoride or chloride content, or both.1.1 This practice provides a procedure for the preparation of samples of plutonium (Pu) materials, using pyrohydrolysis, for subsequent measurement of fluoride, chloride, or both, by ion chromatography (IC) or ion-selective electrode (ISE).1.2 This practice utilizes a sample size of 0.3 ± 0.1 g and is therefore suitable when the larger sample size used in Test Methods C697 and C698 is not available.1.3 Test materials within the scope of this practice include plutonium dioxide powder and mixed (U, Pu) oxide powder. Pellets of plutonium dioxide and mixed (U, Pu) oxide may also be treated after pulverization and with use of an accelerant. Samples of neptunium oxide may also be prepared using this practice.1.4 Full recovery may not be achieved for levels above 50 μg/g fluoride or 50 μg/g chloride (1).2 At higher levels precipitation may occur in the reaction vessel or condenser, or both. The user should validate suitability of the method above these levels.1.5 The procedure described in this practice may be applicable to other plutonium materials, such as plutonium compounds and scrap metals. The user must determine the safety and applicability of this practice to such materials.1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.7 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.1.8 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.