ASTM C1855-18
(Test Method)Standard Test Method for Determination of Uranium and Plutonium Concentration in Aqueous Solutions Using Hybrid K-Edge Densitometry and X-Ray Fluorescence
Standard Test Method for Determination of Uranium and Plutonium Concentration in Aqueous Solutions Using Hybrid K-Edge Densitometry and X-Ray Fluorescence
SIGNIFICANCE AND USE
5.1 The HKED technique is highly element specific and depends upon a well-known controlled geometry.
5.2 The HKED technique can provide concentration measurements of actinides in solutions with precision typically better than 0.3 % for uranium concentrations >50 g/L and 1 % for plutonium in typical U-Pu solutions for a typical measurement time of 3 × 1000 s (3 replicates, 1000 s live time each) (1).
5.3 For pure plutonium only product solutions, the KED technique can achieve measurement precisions better than 0.3 % for plutonium concentrations >50 g/L for a typical measurement time of 3 × 1000 s.
5.4 For pure uranium only solutions, precisions of better than 0.3 % can be achieved using the KED technique for uranium concentrations >50 g/L, for a typical measurement time of 3 × 3600 s.
5.5 For uranium only or plutonium only solutions of concentrations approximately 1 g/L, assayed using XRF, a measurement precision of 1.0 % has been achieved (1). For solutions of concentration approximately 50 g/L, assayed using XRF, measurement precisions of 0.2 % or better have been achieved. The typical measurement time for stand-alone XRF assay is 3 × 3000 s.
5.6 Quality Control (QC) samples are assayed for a typical measurement time of 3 × 3000 s.
5.7 It is applicable when solutions to be measured are homogeneous with respect to chemical composition.
5.8 Results are typically used for fuel fabrication, process control, quality control, material control and accountancy, and safeguards in nuclear fuel reprocessing plants. Each application can have its own data quality objectives (Guide C1068).
5.9 The HKED instrument may use a single cylindrical vial for both the KED and XRF measurements, or separate sample containers for KED and XRF. The typical values for the path length of the rectangular cuvette and the inner diameter of the cylindrical vial are given in 7.8.
5.10 The transfer of the sample into the HKED system can be accomplished either horizontally b...
SCOPE
1.1 This test method specifies the determination of the volumetric uranium and plutonium concentrations, typically, in nitric acid solutions through the combination of K-Edge absorption Densitometry (KED) and K X-Ray fluorescence (XRF) using an X-Ray generator. It is known as the “Hybrid K-Edge” (HKED) technique whose original implementation is described in Ref (1).2 The method is applicable to dissolver (input) solutions and product solutions. The test method also specifies the determination of low concentrations (
1.2 This test method is applicable to the following common-use conditions:
1.2.1 Spent nuclear fuel reprocessing and fuel production.
1.2.2 Homogeneous aqueous solutions contained in cylindrical vials or cuvettes. HKED systems may use two separate sample containers, namely a rectangular cuvette for KED and a cylindrical vial for XRF. Alternatively, there are HKED systems 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 cylindrical vial for XRF) are compliant with the International Target Values (ITV) (1).
1.2.4 The precision results produced by the single cylindrical vial configuration are degraded in comparison to the two container system.
1.2.5 This test method is applicable to facilities that do not adopt the ITVs, but have their own Data Quality Objectives (DQO).
1.2.6 Solutions which contain uranium and plutonium with uranium concentration of 150 to 250 g/L and a U:Pu ratio of 100:1 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 where a minor element such as U needs to be quantified in which Pu is the major element.
1.2.6.2 This test method is applicable for common use process control applications for quantifying Pu in the 5 g/L to 30 g/L range ...
General Information
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Standards Content (Sample)
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.
Designation: C1855 − 18
Standard Test Method for
Determination of Uranium and Plutonium Concentration in
Aqueous Solutions Using Hybrid K-Edge Densitometry and
1
X-Ray Fluorescence
This standard is issued under the fixed designation C1855; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.2.6 Solutions which contain uranium and plutonium with
uranium concentration of 150 to 250 g/L and a U:Pu ratio of
1.1 This test method specifies the determination of the
100:1 typically, in the presence of fission products with β, γ,
volumetricuraniumandplutoniumconcentrations,typically,in
activity of up to 10 TBq/L.
nitric acid solutions through the combination of K-Edge
1.2.6.1 This test method is not applicable to samples where
absorption Densitometry (KED) and K X-Ray fluorescence
a minor element such as U needs to be quantified in which Pu
(XRF) using an X-Ray generator. It is known as the “Hybrid
is the major element.
K-Edge” (HKED) technique whose original implementation is
2
1.2.6.2 This test method is applicable for common use
described in Ref (1). The method is applicable to dissolver
process control applications for quantifying Pu in the 5 g/L to
(input) solutions and product solutions. The test method also
30 g/L range using XRF only in the presence of up to ~10%
specifies the determination of low concentrations (<50 g/L) of
(~100 000 ppm) of transuranic impurities (predominantly U
U and Pu using XRF measurements alone (the “stand-alone
andAm). In this application, the impurity concentration in the
XRF” mode). Using the XRF measurement in the stand-alone
Pu samples is not quantified.Additional uncertainties must be
mode, solutions in the 0.2 g/L to 50 g/L range of Pu with or
estimated and factored in the Pu concentration results.
withoutUandsolutionsinthe0.2g/Lto50g/LrangeofUwith
1.2.7 Solutions containing 50 g/L to 400 g/L of uranium
or without Pu are commonly measured.
alone.
1.2 Thistestmethodisapplicabletothefollowingcommon-
1.2.8 Solutions containing 50 g/L to 400 g/L of plutonium
use conditions:
alone.
1.2.1 Spent nuclear fuel reprocessing and fuel production.
1.2.9 Solutions with low concentrations of U and Pu,
1.2.2 Homogeneous aqueous solutions contained in cylin-
typically in the 0.2 g/L to 50 g/L range.
drical vials or cuvettes. HKED systems may use two separate
sample containers, namely a rectangular cuvette for KED and 1.2.10 The concentration ranges given in 1.2.6 – 1.2.9 are
application of the HKED technique for Materials Control and
a cylindrical vial for XRF. Alternatively, there are HKED
systemsthatuseasamplecontainedinasinglecylindricalvial, Accountancy (MC&A) purposes. For process control applica-
tions where precision requirements are less stringent, KED
for both K-Edge and XRF.
1.2.3 The results produced by the two sample configuration methodcanbeusedtoassaysampleswithlowerconcentrations
of U or Pu (down to 30 g/L).
(a rectangular cuvette for K-Edge densitometry and a cylindri-
cal vial for XRF) are compliant with the International Target
1.3 Units—The values stated in SI units are to be regarded
Values (ITV) (1).
asstandard.Nootherunitsofmeasurementareincludedinthis
1.2.4 The precision results produced by the single cylindri-
standard.
cal vial configuration are degraded in comparison to the two
1.4 This standard does not purport to address all of the
container system.
safety concerns, if any, associated with its use. It is the
1.2.5 This test method is applicable to facilities that do not
responsibility of the user of this standard to establish appro-
adopt the ITVs, but have their own Data Quality Objectives
priate safety, health, and environmental practices and deter-
(DQO).
mine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accor-
1
ThistestmethodisunderthejurisdictionofASTMCommitteeC26onNuclear
dance with internationally recognized principles on standard-
Fuel Cycle and is the direct responsibility of Subcommittee C26.10 on Non
Destructive Assay.
ization established in the Decision on Principles for the
Current edition approved June 1, 2018. Published August 2018. DOI: 10.1520/
Development of International Standards, Guides and Recom-
C1855-18.
2 mendations issued by the World Trade Organization Technical
The boldface numbers in parentheses refer to a list of references at the end of
this standard. Barriers to Trade (TBT) Committee.
Copyright © ASTM Internationa
...
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