Scope

1.1 This test method specifies the determination of thevolumetric uranium and plutonium concentrations, typically, innitric acid solutions through the combination of K-Edgeabsorption Densitometry (KED) and K X-Ray fluorescence(XRF) using an X-Ray generator. It is known as the “HybridK-Edge” (HKED) technique whose original implementation isdescribed in Ref (1).2 The method is applicable to dissolver(input) solutions and product solutions. The test method alsospecifies the determination of low concentrations (<50 g/L) ofU and Pu using XRF measurements alone (the “stand-aloneXRF” mode). Using the XRF measurement in the stand-alonemode, solutions in the 0.2 g/L to 50 g/L range of Pu with orwithout U and solutions in the 0.2 g/L to 50 g/L range of U withor without Pu are commonly measured.1.2 This test method is applicable to the following commonuseconditions:1.2.1 Spent nuclear fuel reprocessing and fuel production.1.2.2 Homogeneous aqueous solutions contained in cylindricalvials or cuvettes. HKED systems may use two separatesample containers, namely a rectangular cuvette for KED anda cylindrical vial for XRF. Alternatively, there are HKEDsystems that use a sample contained in a single cylindrical vial,for both K-Edge and XRF.1.2.3 The results produced by the two sample configuration(a rectangular cuvette for K-Edge densitometry and a cylindricalvial for XRF) are compliant with the International TargetValues (ITV) (1).1.2.4 The precision results produced by the single cylindricalvial configuration are degraded in comparison to the twocontainer system.1.2.5 This test method is applicable to facilities that do notadopt the ITVs, but have their own Data Quality Objectives(DQO).1.2.6 Solutions which contain uranium and plutonium withuranium concentration of 150 to 250 g/L and a U:Pu ratio of100:1 typically, in the presence of fission products with β, γ,activity of up to 10 TBq/L.1.2.6.1 This test method is not applicable to samples wherea minor element such as U needs to be quantified in which Puis the major element.1.2.6.2 This test method is applicable for common useprocess control applications for quantifying Pu in the 5 g/L to30 g/L range using XRF only in the presence of up to ~10 %(~100 000 ppm) of transuranic impurities (predominantly Uand Am). In this application, the impurity concentration in thePu samples is not quantified. Additional uncertainties must beestimated and factored in the Pu concentration results.1.2.7 Solutions containing 50 g/L to 400 g/L of uraniumalone.1.2.8 Solutions containing 50 g/L to 400 g/L of plutoniumalone.1.2.9 Solutions with low concentrations of U and Pu,typically in the 0.2 g/L to 50 g/L range.1.2.10 The concentration ranges given in 1.2.6 – 1.2.9 areapplication of the HKED technique for Materials Control andAccountancy (MC&A) purposes. For process control applicationswhere precision requirements are less stringent, KEDmethod can be used to assay samples with lower concentrationsof U or Pu (down to 30 g/L).1.3 Units—The values stated in SI units are to be regardedas standard. No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appropriatesafety, health, and environmental practices and determinethe applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordancewith internationally recognized principles on standardizationestablished in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendationsissued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.

General Product Information

Published
Document Type	Standard
Status	Current
Publisher	American Society for Testing and Materials
Pages
ISBN
Committee	C 26