【国外标准】 Standard Practice for The Ion Exchange Separation of Uranium and Plutonium Prior to Isotopic Analysis

5.1 Uranium and plutonium are used in nuclear reactor fuel and must be analyzed to insure that they meet certain criteria for isotopic composition as described in Specifications C833 and C1008. This practice is used to chemically separate the same mass peak interferences from uranium and plutonium and from other impurities prior to isotopic abundance determination by thermal ionization mass spectrometry.5.2 In those facilities where perchloric acid use is tolerated, the separation in Test Method C698 may be used prior to isotopic abundance determination. Uranium and plutonium concentrations as well as isotopic abundances using thermal ionization mass spectrometry can be determined using this separation and following Test Method C1625.1.1 This practice is for the ion exchange separation of uranium and plutonium from each other and from other impurities for subsequent isotopic analysis by thermal ionization mass spectrometry. Plutonium-238 and uranium-238, and plutonium-241 and americium-241, will appear as the same mass peak and must be chemically separated prior to analysis. Only high purity solutions can be analyzed reliably using thermal ionization mass spectrometry.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 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.1.4 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.