ASTM C1718-10(2019)
(Test Method)Standard Test Method for Nondestructive Assay of Radioactive Material by Tomographic Gamma Scanning
Standard Test Method for Nondestructive Assay of Radioactive Material by Tomographic Gamma Scanning
SIGNIFICANCE AND USE
5.1 The TGS provides a nondestructive means of mapping the attenuation characteristics and the distribution of the radionuclide content of items on a voxel by voxel basis. Typically in a TGS analysis a vertical layer (or segment) of an item will be divided into a number of voxels. By comparison, a segmented gamma scanner (SGS) can determine matrix attenuation and radionuclide concentrations only on a segment by segment basis.
5.2 It has been successfully used to quantify 238Pu, 239Pu, and 235U. SNM loadings from 0.5 g to 200 g of 239Pu (5, 6), from 1 g to 25 g of 235U (7), and from 0.1 to 1 g of 238Pu have been successfully measured. The TGS technique has also been applied to assaying radioactive waste generated by nuclear power plants (NPP). Radioactive waste from NPP is dominated by activation products (for example, 54Mn, 58Co, 60Co, 110mAg) and fission products (for example, 137Cs, 134Cs). The radionuclide activities measured in NPP waste is in the range from 3.7E+04 Bq to 1.0E+07 Bq. Some results of TGS application to non-SNM radionuclides can be found in the literature (8).
5.3 The TGS technique is well suited for assaying items that have heterogeneous matrices and that contain a non-uniform radionuclide distribution.
5.4 Since the analysis results are obtained on a voxel by voxel basis, the TGS technique can in many situations yield more accurate results when compared to other gamma ray techniques such as SGS.
5.5 In determining the radionuclide distribution inside an item, the TGS analysis explicitly takes into account the cross talk between various vertical layers of the item.
5.6 The TGS analysis technique uses a material basis set method that does not require the user to select a mass attenuation curve apriori, provided the transmission source has at least 2 gamma lines that span the energy range of interest.
5.7 A commercially available TGS system consists of building blocks that can easily be configured to operate the system in the ...
SCOPE
1.1 This test method describes the nondestructive assay (NDA) of gamma ray emitting radionuclides inside containers using tomographic gamma scanning (TGS). High resolution gamma ray spectroscopy is used to detect and quantify the radionuclides of interest. The attenuation of an external gamma ray transmission source is used to correct the measurement of the emission gamma rays from radionuclides to arrive at a quantitative determination of the radionuclides present in the item.
1.2 The TGS technique covered by the test method may be used to assay scrap or waste material in cans or drums in the 1 to 500 litre volume range. Other items may be assayed as well.
1.3 The test method will cover two implementations of the TGS procedure: (1) Isotope Specific Calibration that uses standards of known radionuclide masses (or activities) to determine system response in a mass (or activity) versus corrected count rate calibration, that applies to only those specific radionuclides for which it is calibrated, and (2) Response Curve Calibration that uses gamma ray standards to determine system response as a function of gamma ray energy and thereby establishes calibration for all gamma emitting radionuclides of interest.
1.4 This test method will also include a technique to extend the range of calibration above and below the extremes of the measured calibration data.
1.5 The assay technique covered by the test method is applicable to a wide range of item sizes, and for a wide range of matrix attenuation. The matrix attenuation is a function of the matrix composition, photon energy, and the matrix density. The matrix types that can be assayed range from light combustibles to cemented sludge or concrete. It is particularly well suited for items that have heterogeneous matrix material and non-uniform radioisotope distributions. Measured transmission values should be available to permit valid attenuation corrections, but are not n...
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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: C1718 − 10 (Reapproved 2019)
Standard Test Method for
Nondestructive Assay of Radioactive Material by
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Tomographic Gamma Scanning
This standard is issued under the fixed designation C1718; 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 mission values should be available to permit valid attenuation
corrections, but are not needed for all volume elements in the
1.1 This test method describes the nondestructive assay
container, for example, if interpolation is justified.
(NDA) of gamma ray emitting radionuclides inside containers
using tomographic gamma scanning (TGS). High resolution
1.6 The values stated in SI units are to be regarded as
gamma ray spectroscopy is used to detect and quantify the
standard. No other units of measurement are included in this
radionuclidesofinterest.Theattenuationofanexternalgamma
standard.
ray transmission source is used to correct the measurement of
1.7 This standard does not purport to address all of the
the emission gamma rays from radionuclides to arrive at a
safety concerns, if any, associated with its use. It is the
quantitative determination of the radionuclides present in the
responsibility of the user of this standard to establish appro-
item.
priate safety, health, and environmental practices and deter-
1.2 The TGS technique covered by the test method may be
mine the applicability of regulatory limitations prior to use.
used to assay scrap or waste material in cans or drums in the 1
1.8 This international standard was developed in accor-
to500litrevolumerange.Otheritemsmaybeassayedaswell.
dance with internationally recognized principles on standard-
1.3 The test method will cover two implementations of the
ization established in the Decision on Principles for the
TGS procedure: (1) Isotope Specific Calibration that uses
Development of International Standards, Guides and Recom-
standards of known radionuclide masses (or activities) to
mendations issued by the World Trade Organization Technical
determine system response in a mass (or activity) versus
Barriers to Trade (TBT) Committee.
corrected count rate calibration, that applies to only those
specific radionuclides for which it is calibrated, and (2)
2. Referenced Documents
Response Curve Calibration that uses gamma ray standards to
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determine system response as a function of gamma ray energy
2.1 ASTM Standards:
and thereby establishes calibration for all gamma emitting
C1030TestMethodforDeterminationofPlutoniumIsotopic
radionuclides of interest.
Composition by Gamma-Ray Spectrometry
1.4 This test method will also include a technique to extend C1128Guide for Preparation of Working Reference Materi-
the range of calibration above and below the extremes of the als for Use in Analysis of Nuclear Fuel Cycle Materials
measured calibration data. C1156Guide for Establishing Calibration for a Measure-
ment Method Used toAnalyze Nuclear Fuel Cycle Mate-
1.5 The assay technique covered by the test method is
rials
applicable to a wide range of item sizes, and for a wide range
C1490GuidefortheSelection,TrainingandQualificationof
of matrix attenuation. The matrix attenuation is a function of
Nondestructive Assay (NDA) Personnel
the matrix composition, photon energy, and the matrix density.
C1592/C1592MGuide for Making Quality Nondestructive
The matrix types that can be assayed range from light
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Assay Measurements (Withdrawn 2018)
combustibles to cemented sludge or concrete. It is particularly
C1673Terminology of C26.10 NondestructiveAssay Meth-
well suited for items that have heterogeneous matrix material
ods
and non-uniform radioisotope distributions. Measured trans-
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ThistestmethodisunderthejurisdictionofASTMCommitteeC26onNuclear For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Fuel Cycle and is the direct responsibility of Subcommittee C26.10 on Non contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Destructive Assay. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Feb. 1, 2019. Published February 2019. Originally the ASTM website.
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approved in 2010. Last previous edition approved in 2010 as C1718–10. DOI: The last approved version of this historical standard is referenced on
10.1520/C1718-10R19. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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