ASTM E393-19
(Test Method)Standard Test Method for Measuring Reaction Rates by Analysis of Barium-140 From Fission Dosimeters
Standard Test Method for Measuring Reaction Rates by Analysis of Barium-140 From Fission Dosimeters
SIGNIFICANCE AND USE
5.1 Refer to Guide E844 for the selection, irradiation, and quality control of neutron dosimeters.
5.2 Refer to Practice E261 for a general discussion of the measurement of neutron fluence rate and fluence. The neutron spectrum must be known in order to measure neutron fluence rates with a single detector. Also it is noted that cross sections are continuously being reevaluated. The latest recommended cross sections and details on how they can be obtained are discussed in Guide E1018.
5.3 The reaction rate of a detector nuclide of known cross section, when combined with information about the neutron spectrum, permits the determination of the magnitude of the fluence rate impinging on the detector. Furthermore, if results from other detectors are available, the neutron spectrum can be defined more accurately. The techniques for fluence rate and fluence determinations are explained in Practice E261.
5.4 140Ba is a radioactive nuclide formed as a result of fission. Although it is formed in fission of any heavy atom, the relative yield will differ. Table 1 gives recommended cumulative fission yields for 140Ba production and direct (independent) fission yields for the daughter product 140La. The independent fission yields for 140La are relatively low compared to the 140Ba cumulative fission yield and will not significantly affect the accuracy of the nondestructive procedure and need not be considered. (A) Thermal = 0.0253 eV19.(B) Fast = 0.4 MeV.(C) From JEF-3.1.1 (Ref (1, 2)), except as noted. Uncertainties in percent of given value.(D) From ENDF/B-VIII.0 (Ref (3)). Not available in JEF-3.1.1. Uncertainties in percent of given value.
5.5 The half-life of 140Ba is 12.752 days. Its daughter 140La has a half-life of 1.6781 days (4).3 The comparatively long half-life of 140Ba allows the counting to be delayed several weeks after irradiation in a high-neutron field. However, to achieve maximum sensitivity the daughter product 140La should be counted five to...
SCOPE
1.1 This test method describes two procedures for the measurement of reaction rates by determining the amount of the fission product 140Ba produced by the non-threshold reactions 235U(n,f), 241Am(n,f), and 239Pu(n,f), and by the threshold reactions 238U(n,f), 237Np(n,f), and 232Th(n,f).
1.2 These reactions produce many fission products, among which is 140Ba, having a half-life of 12.752 days. 140Ba emits gamma rays of several energies; however, these are not easily detected in the presence of other fission products. Competing activity from other fission products requires that a chemical separation be employed or that the 140Ba activity be determined indirectly by counting its daughter product 140La. This test method describes both procedure (a), the nondestructive determination of 140Ba by the direct counting of 140La several days after irradiation, and procedure (b), the chemical separation of 140Ba and the subsequent counting of 140Ba or its daughter 140 La.
1.3 With suitable techniques, fission neutron fluence rates can be measured in the range from 107 n (neutrons) · cm−2 · s−1 to approximately 1015 n · cm−2 · s−1.
1.4 The measurement of time-integrated reaction rates with fission dosimeters by 140Ba analysis is limited by the half-life of 140Ba to irradiation times up to about six weeks.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 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.
1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the De...
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: E393 − 19
Standard Test Method for
Measuring Reaction Rates by Analysis of Barium-140 From
1
Fission Dosimeters
This standard is issued under the fixed designation E393; 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 ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.1 This test method describes two procedures for the
mendations issued by the World Trade Organization Technical
measurement of reaction rates by determining the amount of
140 Barriers to Trade (TBT) Committee.
the fission product Ba produced by the non-threshold
235 241 239
reactions U(n,f), Am(n,f), and Pu(n,f), and by the
2. Referenced Documents
238 237 232
threshold reactions U(n,f), Np(n,f), and Th(n,f).
2
2.1 ASTM Standards:
1.2 These reactions produce many fission products, among
C697Test Methods for Chemical, Mass Spectrometric, and
140 140
which is Ba, having a half-life of 12.752 days. Ba emits
Spectrochemical Analysis of Nuclear-Grade Plutonium
gamma rays of several energies; however, these are not easily
Dioxide Powders and Pellets
detected in the presence of other fission products. Competing
D1193Specification for Reagent Water
activity from other fission products requires that a chemical
E170Terminology Relating to Radiation Measurements and
140
separation be employed or that the Ba activity be deter-
Dosimetry
140
mined indirectly by counting its daughter product La. This
E181Test Methods for Detector Calibration andAnalysis of
test method describes both procedure (a), the nondestructive
Radionuclides
140 140
determination of Ba by the direct counting of La several
E261Practice for Determining Neutron Fluence, Fluence
days after irradiation, and procedure (b), the chemical separa-
Rate, and Spectra by Radioactivation Techniques
140 140
tion of Ba and the subsequent counting of Ba or its
E704Test Method for Measuring Reaction Rates by Radio-
140
daughter La.
activation of Uranium-238
1.3 With suitable techniques, fission neutron fluence rates E705Test Method for Measuring Reaction Rates by Radio-
7 −2 −1
canbemeasuredintherangefrom10 n(neutrons)·cm ·s activation of Neptunium-237
15 −2 −1
to approximately 10 n·cm ·s .
E844Guide for Sensor Set Design and Irradiation for
Reactor Surveillance
1.4 The measurement of time-integrated reaction rates with
140
E944Guide for Application of Neutron Spectrum Adjust-
fission dosimeters by Ba analysis is limited by the half-life
140 ment Methods in Reactor Surveillance
of Ba to irradiation times up to about six weeks.
E1005Test Method for Application and Analysis of Radio-
1.5 The values stated in SI units are to be regarded as
metric Monitors for Reactor Vessel Surveillance
standard. No other units of measurement are included in this
E1018Guide for Application of ASTM Evaluated Cross
standard.
Section Data File
1.6 This standard does not purport to address all of the
3. Terminology
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
3.1 Definitions:
priate safety, health, and environmental practices and deter-
3.1.1 Refer to Terminology E170.
mine the applicability of regulatory limitations prior to use.
4. Summary of Test Method
1.7 This international standard was developed in accor-
dance with internationally recognized principles on standard-
4.1 For nondestructive analysis, the fission dosimeter is
allowed to cool for five days or more. The 1.596-MeV gamma
140
energy peak of La, which is the daughter product of the
1
ThistestmethodisunderthejurisdictionofASTMCommitteeE10onNuclear
Technology and Applicationsand is the direct responsibility of Subcommittee
2
E10.05 on Nuclear Radiation Metrology. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2019. Published December 2019. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1984. Last previous edition approved in 2013 as E393–13. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/E0393-19. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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E393 − 19
140 140
Ba, is then counted. This information, combined with the of the irradiation. The Ba decay constan
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