ASTM E692-08
(Test Method)Standard Test Method for Determining the Content of Cesium-137 in Irradiated Nuclear Fuels by High-Resolution Gamma-Ray Spectral Analysis (Withdrawn 2013)
Standard Test Method for Determining the Content of Cesium-137 in Irradiated Nuclear Fuels by High-Resolution Gamma-Ray Spectral Analysis (Withdrawn 2013)
SIGNIFICANCE AND USE
This test method uses a high-resolution gamma-ray spectrometer as a basis for measuring the gamma-ray emission rate of 137Cs-137mBa in a dilute nitric acid solution containing 10 mg/L of cesium carrier. No chemical separation of the cesium from the dissolved-fuel solution is required. The principal steps consist of diluting a weighed aliquot of the dissolved-fuel solution with a known mass of 1 M nitric acid (HNO3) and measuring the 662 keV gamma-ray count rate from the sample, then measuring the 662 keV gamma-ray count rate from a standard source that has the same physical form and counting geometry as the sample.
The amount of fuel sample required for the analysis is small. For a sample containing 0.1 g of fuel irradiated to one atom percent fission, a net count rate of approximately 105 counts per second will be observed for a counting geometry that yields a full-energy peak efficiency fraction of 1 × 10-3. The advantage of this small amount of sample is that the concentration of fuel material can be kept at levels well below 1 g/L, which results in negligible self-absorption in the sample aliquot and a small radiation hazard to the analyst.
SCOPE
1.1 This test method covers the determination of the number of atoms of 137Cs in aqueous solutions of irradiated uranium and plutonium nuclear fuel. When combined with a method for determining the initial number of fissile atoms in the fuel, the results of this analysis allows atom percent fission (burn-up) to be calculated (1). The determination of atom percent fission, uranium and plutonium concentrations, and isotopic abundances are covered in Test Methods E 267 and E 321.
1.2 137Cs is not suitable as a fission monitor for samples that may have lost cesium during reactor operation. For example, a large temperature gradient enhances 137Cs migration from the fuel region to cooler regions such as the radial fuel-clad gap, or, to a lesser extent, towards the axial fuel end.
1.3 A nonuniform 137Cs distribution should alert the analyst to the potential loss of the fission product nuclide. The 137Cs distribution may be ascertained by an axial gamma-ray scan of the fuel element to be assayed. In a mixed-oxide fuel, comparison of the 137Cs distribution with the distribution of nonmigrating fission-product nuclides such as 95Zr or 144Ce would indicate the relative degree of 137Cs migration.
1.4 The values stated in SI units are to be regarded as standard. No other unites of measurement are included in this standard.
1.5 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.
WITHDRAWN RATIONALE
This test method covers the determination of the number of atoms of���137Cs in aqueous solutions of irradiated uranium and plutonium nuclear fuel. When combined with a method for determining the initial number of fissile atoms in the fuel, the results of this analysis allows atom percent fission (burn-up) to be calculated.
Formerly under the jurisdiction of Committee C26 on Nuclear Fuel Cycle, this test method was withdrawn in January 2013. This standard is being withdrawn without replacement due to its limited use by industry.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E692 − 08
StandardTest Method for
Determining the Content of Cesium-137 in Irradiated Nuclear
1
Fuels by High-Resolution Gamma-Ray Spectral Analysis
This standard is issued under the fixed designation E692; 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 2. Referenced Documents
3
1.1 Thistestmethodcoversthedeterminationofthenumber 2.1 ASTM Standards:
137
of atoms of Cs in aqueous solutions of irradiated uranium E170Terminology Relating to Radiation Measurements and
andplutoniumnuclearfuel.Whencombinedwithamethodfor Dosimetry
determining the initial number of fissile atoms in the fuel, the E181Test Methods for Detector Calibration andAnalysis of
resultsofthisanalysisallowsatompercentfission(burn-up)to Radionuclides
2
be calculated (1). The determination of atom percent fission, E219Test Method for Atom Percent Fission in Uranium
uranium and plutonium concentrations, and isotopic abun- Fuel(RadiochemicalMethod)(Discontinued2001)(With-
4
dances are covered in Test Methods E267 and E321. drawn 2001)
137 E267Test Method for Uranium and Plutonium Concentra-
1.2 Csisnotsuitableasafissionmonitorforsamplesthat
tions and Isotopic Abundances
may have lost cesium during reactor operation. For example, a
137 E321TestMethodforAtomPercentFissioninUraniumand
large temperature gradient enhances Cs migration from the
Plutonium Fuel (Neodymium-148 Method)
fuel region to cooler regions such as the radial fuel-clad gap,
or, to a lesser extent, towards the axial fuel end.
3. Summary of Test Method
137
137 5
1.3 Anonuniform Csdistributionshouldalerttheanalyst
3.1 Csisassayedbymeasuringthe662 keVgamma-ray
137
6
to the potential loss of the fission product nuclide. The Cs
emissionratefromtheisomerictransitionofitsmetastable2.6
137m
distribution may be ascertained by an axial gamma-ray scan of
min Ba daughter, using a high-resolution germanium de-
the fuel element to be assayed. In a mixed-oxide fuel, com-
tector and multichannel pulse-height analyzer. Refer to Test
137
parison of the Cs distribution with the distribution of non-
Methods E181.
95 144
migratingfission-productnuclidessuchas Zror Cewould
137
137 3.2 The number of atoms of Cs in a sample is computed
indicate the relative degree of Cs migration.
from the measured net gamma-ray count rate relative to the
137
1.4 The values stated in SI units are to be regarded as
measured net gamma-ray count rate from a standard Cs
standard. No other unites of measurement are included in this
solution.
standard.
4. Significance and Use
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 4.1 This test method uses a high-resolution gamma-ray
responsibility of the user of this standard to establish appro- spectrometer as a basis for measuring the gamma-ray emission
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
1
ThistestmethodisunderthejurisdictionofASTMCommitteeC26onNuclear the ASTM website.
4
Fuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods of The last approved version of this historical standard is referenced on
Test. www.astm.org.
5
Current edition approved July 1, 2008. Published September 2008. Originally TheenergyofthegammarayismorepreciselygiveninRef (2)as661.637keV.
approved in 1979. Last previous edition approved in 2000 as E692–00. DOI: For simplicity, all citations of this energy in this standard will be given as 662 keV.
6
10.1520/E0692-08. The half-life of this state is more precisely given in Ref (3) as 2.552 min. For
2
Theboldfacenumbersinparenthesesrefertothelistofreferencesattheendof simplicity, all citations of this half-life listed in this standard will be given as 2.6
this test method. min.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
E692 − 08
FIG. 1 Gamma-Ray Spectrum of a (Pu,U)O Fuel, Irradiated to 6 Atom % Fission, and Decayed for Seven Months
2
137 137m
rate of Cs- Ba in a dilute nitric acid solution containing (defined in Terminology E170) from the 766 keV gamma ray
95 134
10 mg/L of cesium carrier. No chemical separation of the of Nb and from the 796 keV gamma ray of Cs, as shown
cesium from the dissolved-fuel solution is required. The i
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.