ASTM E393-96
(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
SCOPE
1.1 This test method describes two procedures for the measurement of reaction rates by determining the amount of the fission product Ba produced by the non-threshold reactions 235 U (n, f), 241 Am (n, f), and 239 Pu (n, f), and by the threshold reactions 238 U (n, f), 237 Np (n, f), and 232 Th (n, f).
1.2 These reactions produce many fission products, among which is 140 Ba, having a half-life of 12.752 days. 140 Ba 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 Ba activity be determined indirectly by counting its daughter product La. This test method describes both procedure (a), the nondestructive determination of Ba by the direct counting of La several days after irradiation, and procedure (b), the chemical separation of Ba and the subsequent counting of Ba or its daughter 140 La.
1.3 With suitable techniques, fission neutron fluence rates can be measured in the range from 10 n (neutrons) [dot]cm -2 [dot]s -1 to approximately 10 15 n[dot]cm -2 [dot]s -1 .
1.4 The measurement of time-integrated reaction rates with fission dosimeters by Ba analysis is limited by the half-life of 140 Ba to irradiation times up to about six weeks.
1.5 The values stated in SI units are to be regarded as 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 and health practices and determine the applicability of regulatory limitations prior to use.
General Information
Relations
Standards Content (Sample)
Designation: E 393 – 96
Standard Test Method for
Measuring Reaction Rates by Analysis of Barium-140 From
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Fission Dosimeters
This standard is issued under the fixed designation E 393; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
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1. Scope Dioxide Powders and Pellets
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D 1193 Specification for Reagent Water
1.1 This test method describes two procedures for the
E 170 Terminology Relating to Radiation Measurements
measurement of reaction rates by determining the amount of
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140
and Dosimetry
the fission product Ba produced by the non-threshold reac-
235 241 239
E 181 Test Methods for Detector Calibration and Analysis
tions U (n, f), Am (n, f), and Pu (n, f), and by the
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238 237 232
of Radionuclides
threshold reactions U (n, f), Np (n, f), and Th (n, f).
E 261 Practice for Determining Neutron Fluence Rate, Flu-
1.2 These reactions produce many fission products, among
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140 140
ence, and Spectra by Radioactivation Techniques
which is Ba, having a half-life of 12.752 days. Ba emits
E 704 Test Method for Measuring Reaction Rates by Ra-
gamma rays of several energies; however, these are not easily
4
dioactivation of Uranium-238
detected in the presence of other fission products. Competing
E 705 Test Method for Measuring Reaction Rates By Ra-
activity from other fission products requires that a chemical
4
140
dioactivation of Neptunium-237
separation be employed or that the Ba activity be determined
140
E 844 Guide for Sensor Set Design and Irradiation for
indirectly by counting its daughter product La. This test
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Reactor Surveillance, E706 (IIC)
method describes both procedure (a), the nondestructive deter-
140 140
E 944 Guide for Application of Neutron Spectrum Adjust-
mination of Ba by the direct counting of La several days
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ment Methods in Reactor Surveillance, (IIA)
after irradiation, and procedure (b), the chemical separation of
140
E 1005 Test Method for Application and Analysis of Radio-
140Ba and the subsequent counting of Ba or its daughter
metric Monitors for Reactor Vessel Surveillance, E706
140La.
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(IIA)
1.3 With suitable techniques, fission neutron fluence rates
7 −2 −1
E 1018 Guide for Application of ASTM Evaluated Cross
can be measured in the range from 10 n (neutrons) · cm ·s
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15 −2 −1
Section Data File, Matrix E 706 (IIB)
to approximately 10 n·cm ·s .
1.4 The measurement of time-integrated reaction rates with
3. Terminology
140
fission dosimeters by Ba analysis is limited by the half-life
140
3.1 Definitions:
of Ba to irradiation times up to about six weeks.
3.1.1 Refer to Terminology E 170.
1.5 The values stated in SI units are to be regarded as
standard.
4. Summary of Test Method
1.6 This standard does not purport to address all of the
4.1 For nondestructive analysis, the fission dosimeter is
safety concerns, if any, associated with its use. It is the
allowed to cool for five days or more. The 1.596-MeV gamma
responsibility of the user of this standard to establish appro-
140
energy peak of La, which is the daughter product of the
priate safety and health practices and determine the applica-
140Ba, is then counted. This information, combined with the
bility of regulatory limitations prior to use.
decay constants for the La and the Ba, and the fission yield of
140
the Ba gives the reaction fission rate. When the proper cross
2. Referenced Documents
section is used with the reaction rate, the equivalent fission
2.1 ASTM Standards:
fluence rate can be determined.
C 697 Test Methods for Chemical, Mass Spectrometric, and
140
4.2 For destructive analysis, the fission product Ba is
Spectrochemical Analysis of Nuclear-Grade Plutonium
separated from the irradiated fission dosimeter. The activity of
140
the Ba is determined by counting the 0.537 MeV gamma
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This test method is under the jurisdiction of ASTM Committee E-10 on Nuclear
Technology and Applications and is the direct responsibility of Subcommittee
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E10.05 on Nuclear Radiation Metrology. Annual Book of ASTM Standards, Vol 12.01.
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Current edition approved Jan. 10, 1996. Published March 1996. Originally Annual Book of ASTM Standards, Vol 11.01.
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published as E 393 – 84. Last previous edition E 393 – 90. Annual Book of ASTM Standards, Vol 12.02.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
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E 393
140
TABLE 1 Recommended Cumulative Fission Yields for Ba
energy peak. This information is then used as in 4.1 to give the
Production
reaction rate or the equivalent fission fluence rate.
Thermal or Fast
A,B
Fission Dosimeter Fission Yield,%
5. Significance and Use Neutron Field
235
UT 5.84596 6 1%
5.1 Refer to Guide E 844 for the selection, irradiation, and
F 5.98741 6 1%
quality control of neutron dosimeters.
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