iTeh StandardsiTeh Standards
EURUSD
Your shopping cart is empty.
ASTM

ASTM D7784-12

(Practice)

Standard Practice for the Rapid Assessment of Gamma-ray Emitting Radionuclides in Environmental Media by Gamma Spectrometry

Standard Practice for the Rapid Assessment of Gamma-ray Emitting Radionuclides in Environmental Media by Gamma Spectrometry

SIGNIFICANCE AND USE
5.1 This practice was developed for the rapid determination of gamma-emitting radionuclides in environmental media. The results of the test may be used to determine if the activity of these radionuclides in the sample exceeds the action level for the relevant incident or emergency response. The detection limits will be dependent on sample size, counting configuration, and the detector system in use.  
5.2 In most cases, a sample container which is large in diameter and short in height relative to the detector will provide the best gamma-ray detection efficiency. For samples of water or other low-Z materials (e.g., vegetation), the re-entrant or Marinelli-style beaker may yield the best gamma-ray detection efficiency.  
5.3 The density of the sample material and physical parameters of the sample container (e.g., diameter, height, material) may have significant consequences for the accuracy of the sample analysis as compared to the calibration. For this reason, the ideal calibration material and container (often referred to as ‘geometry’) will be exactly the same as the samples to be analyzed. Differences in sample container or sample matrix may introduce significant errors in detector response, especially at low gamma-ray energies. Every effort should be made to account for these differences if the exact calibration geometry is not available.  
5.4 This method establishes an empirical gamma-ray spectrometer calibration using standards traceable to a national standardizing body in a specific geometry selected to ensure that the container, density, and composition of the standard matches that of the samples as closely as possible. However, in some cases it may be beneficial to modify such initial calibrations using mathematical modeling or extrapolations to an alternate geometry. Use of such a model may be acceptable, depending on the measurement quality objectives of the analysis process, and provided that appropriate compensation to uncertainty estimates are inclu...
SCOPE
1.1 This practice covers the quantification of radionuclides in environmental media (e.g., water, soil, vegetation, food) by means of simple preparation and counting with a high-resolution gamma ray detector. Because the practice is designed for rapid analysis, extensive efforts to ensure homogeneity or ideal sample counting conditions are not taken.  
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are provided for information purposes only.  
1.3 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

Status
Historical
Publication Date
31-Oct-2012
ICS
17.240 - Radiation measurements
Technical Committee
D19 - Water
Drafting Committee
D19.04 - Methods of Radiochemical Analysis
Current Stage
Ref Project

Buy Standard

ASTM D7784-12 - Standard Practice for the Rapid Assessment of Gamma-ray Emitting Radionuclides in Environmental Media by Gamma SpectrometryASTM D7784-12 - Standard Practice for the Rapid Assessment of Gamma-ray Emitting Radionuclides in Environmental Media by Gamma Spectrometry
PreviousNext
Standard
ASTM D7784-12 - Standard Practice for the Rapid Assessment of Gamma-ray Emitting Radionuclides in Environmental Media by Gamma Spectrometry
English language
7 pages
sale 15% off
Preview
sale 15% off
Preview

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: D7784 − 12
Standard Practice for the
Rapid Assessment of Gamma-ray Emitting Radionuclides in
1
Environmental Media by Gamma Spectrometry
This standard is issued under the fixed designation D7784; 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 2.2 Other Documents:
PCNUDAT data files National Nuclear Data Center,
1.1 This practice covers the quantification of radionuclides
Brookhaven National Lab, Upton, NY, USA
in environmental media (e.g., water, soil, vegetation, food) by
means of simple preparation and counting with a high-
3. Terminology
resolution gamma ray detector. Because the practice is de-
3.1 Definitions—for definitions of terms used in this
signed for rapid analysis, extensive efforts to ensure homoge-
practice, refer to Terminology D1129.
neity or ideal sample counting conditions are not taken.
4. Summary of Practice
1.2 The values stated in SI units are to be regarded as
4.1 Following sample collection, sample material is placed
standard. The values given in parentheses are provided for
in a suitable container for analysis by a gamma spectrometry
information purposes only.
system. A suitable container is defined as a container which
1.3 This standard does not purport to address all of the
willbothholdthesampleinafixedgeometryandforwhichthe
safety concerns, if any, associated with its use. It is the
gamma spectrometry system has been calibrated. For solid
responsibility of the user of this standard to establish appro-
samples, the samples may be ground, sieved, or otherwise
priate safety, health, and environmental practices and deter-
preparedforthepurposeofvolumereduction,homogenization,
mine the applicability of regulatory limitations prior to use.
or conformance to the calibration standard, as desired.
1.4 This international standard was developed in accor-
dance with internationally recognized principles on standard-
5. Significance and Use
ization established in the Decision on Principles for the
5.1 This practice was developed for the rapid determination
Development of International Standards, Guides and Recom-
of gamma-emitting radionuclides in environmental media.The
mendations issued by the World Trade Organization Technical
results of the test may be used to determine if the activity of
Barriers to Trade (TBT) Committee.
these radionuclides in the sample exceeds the action level for
the relevant incident or emergency response. The detection
2. Referenced Documents
limits will be dependent on sample size, counting
2
2.1 ASTM Standards:
configuration, and the detector system in use.
C998Practice for Sampling Surface Soil for Radionuclides
5.2 In most cases, a sample container which is large in
D1129Terminology Relating to Water
diameter and short in height relative to the detector will
D3370Practices for Sampling Water from Closed Conduits
provide the best gamma-ray detection efficiency. For samples
D3648Practices for the Measurement of Radioactivity
of water or other low-Z materials (e.g., vegetation), the
D3649PracticeforHigh-ResolutionGamma-RaySpectrom-
re-entrantorMarinelli-stylebeakermayyieldthebestgamma-
etry of Water
ray detection efficiency.
D7282Practice for Set-up, Calibration, and Quality Control
5.3 The density of the sample material and physical param-
of Instruments Used for Radioactivity Measurements
eters of the sample container (e.g., diameter, height, material)
may have significant consequences for the accuracy of the
sampleanalysisascomparedtothecalibration.Forthisreason,
1
This practice is under the jurisdiction ofASTM Committee D19 on Water and
theidealcalibrationmaterialandcontainer(oftenreferredtoas
is the direct responsibility of Subcommittee D19.04 on Methods of Radiochemical
‘geometry’) will be exactly the same as the samples to be
Analysis.
analyzed. Differences in sample container or sample matrix
Current edition approved Nov. 1, 2012. Published November 2012. DOI:
10.1520/D7784-12.
may introduce significant errors in detector response, espe-
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
ciallyatlowgamma-rayenergies.Everyeffortshouldbemade
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
to account for these differences if the exact calibration geom-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. etry is not available.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D7784 − 12
TABLE 1 Example of most likely radion
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.

This May Also Interest You

ASTM
ASTM D3648-23(Practice)
Standard Practices for the Measurement of Radioactivity

SIGNIFICANCE AND USE
5.1 This practice was developed for the purpose of summarizing the various generic radiometric techniques, equipment, and practices that are used for the measurement of radioactivity.
SCOPE
1.1 These practices cover a review of the accepted counting practices currently used in radiochemical analyses. The practices are divided into four sections:    
Section    
General Information  
6 – 11  
Alpha Counting  
12 – 22  
Beta Counting  
23 – 33  
Gamma Counting  
34 – 41  
1.2 The general information sections contain information applicable to all types of radioactive measurements, while each of the other sections is specific for a particular type of radiation.  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 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.  
1.5 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.

  • Standard
    28 pages
    English language
    sale 15% off
ASTM
ASTM D7282-21e1(Practice)
Standard Practice for Setup, Calibration, and Quality Control of Instruments Used for Radioactivity Measurements

SIGNIFICANCE AND USE
5.1 This practice is consistent with a performance-based approach wherein the frequency of recalibration and instrument testing is linked to the results from continuing instrument quality control. Under the premise of this practice, a laboratory demonstrates that its instrument performance is acceptable for analyzing sample test sources.  
5.2 When a laboratory demonstrates acceptable performance based on continuing instrument quality control data (that is, control charts and tolerance charts), batch QC samples (that is, blanks, laboratory control samples, replicates, matrix spikes, and other batch QC samples as may be applicable) and independent reference materials, traditional schedule-driven instrument recalibration is permissible but unnecessary.  
5.3 When continuing instrument QC, batch QC, or independent reference material sample results indicate that instrument response has exceeded established control or tolerance limits, instrument calibration is required. Other actions related to sample analyses on the affected instruments may be required by the laboratory QM.  
5.4 The data obtained while following this practice will likely be stored electronically. The data remain in electronic storage, where they are readily available to produce plots, graphs, spreadsheets, and other types of displays and reports. The laboratory QM should specify the frequency and performance of data storage backup.
SCOPE
1.1 This practice covers consensus criteria for the setup, calibration, and quality control of nuclear instruments. Setup establishes the operating parameters of the instrument—for example, voltage or discriminator settings. Calibrations determine the instrument’s response characteristics—for example, its counting efficiency or gain. Quality control ensures that the performance of the instrument remains acceptable for its intended use and consistent with the performance at the time of calibration.  
1.2 This practice addresses four of the most commonly used types of nuclear counting instruments: alpha-particle spectrometer, gamma-ray spectrometer, gas proportional counter, and liquid scintillation counter.  
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions that are provided for information only and are not considered standard.  
1.4 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.  
1.5 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.

  • Standard
    27 pages
    English language
    sale 15% off
ASTM
ASTM D7784-20(Practice)
Standard Practice for the Rapid Assessment of Gamma-ray Emitting Radionuclides in Environmental Media by Gamma Spectrometry

SIGNIFICANCE AND USE
5.1 This practice was developed for the rapid determination of gamma-emitting radionuclides in environmental media. The results of the test may be used to determine if the activity of these radionuclides in the sample exceeds the action level for the relevant incident or emergency response. The detection limits will be dependent on sample size, counting configuration, and the detector system in use.  
5.2 In most cases, a sample container which is large in diameter and short in height relative to the detector will provide the best gamma-ray detection efficiency. For samples of water or other low-Z materials (for example, vegetation), the re-entrant or Marinelli-style beaker may yield the best gamma-ray detection efficiency.  
5.3 The density of the sample material and physical parameters of the sample container (for example, diameter, height, material) may have significant consequences for the accuracy of the sample analysis as compared to the calibration. For this reason, the ideal calibration material and container (often referred to as ‘geometry’) will be exactly the same as the samples to be analyzed. Differences in sample container or sample matrix may introduce significant errors in detector response, especially at low gamma-ray energies. Every effort should be made to account for these differences if the exact calibration geometry is not available.  
5.4 This practice establishes an empirical gamma-ray spectrometer calibration using standards traceable to the SI via a national metrology institute (NMI) such as the National Institute of Standards and Technology (NIST) in the United States and the National Physical Laboratory (NPL) in the United Kingdom in a specific geometry selected to ensure that the container, density, and composition of the standard matches that of the samples as closely as possible. However, in some cases it may be beneficial to modify such initial calibrations using mathematical modeling or extrapolations to an alternate geometry. Use...
SCOPE
1.1 This practice covers the quantification of radionuclides in environmental media (for example, water, soil, vegetation, food) by means of simple preparation and counting with a high-resolution gamma ray detector. Because the practice is designed for rapid analysis, extensive efforts to ensure homogeneity or ideal sample counting conditions are not taken.  
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.  
1.3 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.  
1.4 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.

  • Standard
    7 pages
    English language
    sale 15% off
  • Standard
    7 pages
    English language
    sale 15% off
ASTM
ASTM D8027-17(Practice)
Standard Practice for Concentration of Select Radionuclides Using MnO2 for Measurement Purposes

SIGNIFICANCE AND USE
5.1 This practice is applicable to the separation of specific radionuclides of interest as part of overall radiochemical analytical methods. Radionuclides of interest may need to be quantified at activity levels of less than 1 Bq. This may require measurement of less than 1 fg of analyte in a sample which has a mass of a gram to more than several kilograms. This requires concentration of radionuclides into a smaller volume counting geometry or exclusion of species which would impede subsequent chemical separations, or both. MnO2 has shown good selectivity in being able to concentrate the following elements: actinium (Ac), bismuth (Bi), lead (Pb), polonium (Po), plutonium (Pu), radium (Ra), thorium (Th), and uranium (U) as noted in the referenced literature (see Sections 4 and 8). The MnO2 can be loaded onto a variety of substrates in preparation for use or generated in-situ in an aqueous solution. The presented processes are not meant to be all encompassing of what is possible or meant to address all limitations of using MnO2. Some limitations are noted in Section 6, Interferences.
SCOPE
1.1 This practice is intended to provide a variety of approaches in which manganese oxide (MnO2) can be used to concentrate radionuclides of interest into a smaller volume counting geometry or exclude other species that would otherwise impede subsequent chemical separation steps in an overall radiochemical method, or both.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 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.  
1.4 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.

  • Standard
    5 pages
    English language
    sale 15% off
  • Standard
    5 pages
    English language
    sale 15% off
ASTM
ASTM D7283-17(Test Method)
Standard Test Method for Alpha and Beta Activity in Water By Liquid Scintillation Counting

SIGNIFICANCE AND USE
5.1 This test method is intended for the measurement of gross alpha- and beta-activity concentrations in the analyses of environmental and drinking waters. For samples submitted to satisfy regulatory or permit requirements, the submitter should assure that this or any other method used is acceptable to the regulator or permit issuer.  
5.2 This test method is also applicable to the direct analysis of gross alpha- and beta-activity concentrations in water when low detection limits are not required. Direct analysis provides a rapid method for determination of gross alpha- and beta-activity concentrations when low detection limits are not required.  
5.3 This test method is not capable of discriminating among alpha emitting radionuclides or among beta emitting radionuclides. Those intending to identify and quantify specific radionuclides should use test methods specific to the radionuclides of interest.  
5.4 This test method may not be cited as a method for the determination of gross alpha- or beta-activity concentrations in a solid/soil matrix or the acid digestate of the same. The use of this test method for such applications brings the potential for serious bias and incomparability of results dependent on the matrix constituents, manner of sample preparation or treatment, or both.
SCOPE
1.1 This test method covers the measurement of gross alpha- and beta- activity concentrations in a homogeneous water sample. It is applicable to alpha emitters with activity concentration levels above 0.11 Bq/L (3 pCi/L) and beta emitters with activity concentration levels above 0.15 Bq/L (4 pCi/L). This test method is not applicable to samples containing radionuclides that are volatile under conditions of the analysis.  
1.2 This test method may also be used for the direct measurement of gross alpha- and beta- activity concentrations in homogeneous water samples with alpha emitter activity concentration levels above 1.8 Bq/L (50 pCi/L) and beta emitter activity concentration levels above 3.7 Bq/L (100 pCi/L).  
1.3 This test method was tested using single-operator tests.2,3 A collaborative study following the U.S. EPA “Protocol for the Evaluation of Alternate Test Procedures for Analyzing Radioactive Contaminants in Drinking Water” was performed. The results of this study are on file at ASTM Headquarters.4  
1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to pCi/L that are provided for information only and are not considered standard. An exception is noted in Section 14.  
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.  
1.6 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.

  • Standard
    13 pages
    English language
    sale 15% off
  • Standard
    13 pages
    English language
    sale 15% off
ASTM
ASTM D7939-15(Test Method)
Standard Test Method for Rapid Radiochemical Determination of Americium-241 in Water

SIGNIFICANCE AND USE
5.1 This test method is considered a rapid method when compared to other classical methods for the determination of 241Am in aqueous solutions. During the method validation of this method, a test batch of fourteen test samples plus quality control samples was chemically processed in ~7.5 hours. Additional time for counting the samples depends on the measurement quality objectives.  
5.2 This test method is specific for Americium-241 (241Am) in drinking water and other aqueous samples. However, if any isotopes of curium are present in the sample, they will be carried with americium during the analytical separation process and will be observed in the final alpha spectrum.  
5.3 This test method is capable of achieving a required method uncertainty for 241Am of 0.070 Bq/L at an analytical action level of 0.555 Bq/L. This test method is capable of achieving a required relative method uncertainty, φMR, 13 % above 0.555 Bq/L. This test method is capable of achieving a “required” minimum detectable concentration (MDC) of 0.055 Bq/L.  
5.4 To attain these stated measurement quality objectives (MQOs), a sample volume of approximately 200 mL and count time of at least 1 to 3 hours are recommended. The sample turnaround time and throughput may vary based on additional project MQOs, the time for analysis of the final counting form, and initial sample volume. This test method should be validated before use following the protocols provided in Method Validation Guide for Qualifying Methods Used by Radiological Laboratories Participating in Incident Response Activities.4  
5.5 This test method is intended to be used for water samples that are similar in composition to drinking water. This method was evaluated following the guidance presented for “Level E Method Validation: Adapted or Newly Developed Methods, Including Rapid Methods” in Method Validation Guide for Qualifying Methods Used by Radiological Laboratories Participating in Incident Response Activities and Chapter 6 of ...
SCOPE
1.1 This test method is specifically for Americium-241 (241Am) in drinking water and other aqueous samples. However, if any isotopes of curium are present in the sample, they will be carried with americium during the analytical separation process and will be observed in the final alpha spectrum. The presence of 243Am in the water sample will bias the results obtained by this test method.  
1.2 This test method is applicable to samples in which radioactive contamination is from either known or unknown origins. If any filtration of the sample is performed before starting the analysis, those solids should be analyzed separately. The results from the analysis of these solids should be reported separately (as a suspended activity concentration for the water volume filtered) but identified with the filtrate results.  
1.3 This test method is applicable to the determination of soluble 241Am. This test method is not applicable to the determination of 241Am in highly insoluble particulate matter possibly present in water samples contaminated as a result of a radiological dispersal device (RDD) event.  
1.4 This test method uses rapid radiochemical separation techniques for determining americium in water samples following a radiological or nuclear incident. Although, with this test method, concentrations of 241Am on the same order of magnitude as methods used for the Safe Drinking Water Act (SDWA) can be detected, this test method is not a substitute for SDWA-approved methods for 241Am.  
1.5 Units—The values stated in SI units are to be regarded as the 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 and health practices and determine the applicability of regulatory limitations prior to use.

  • Standard
    14 pages
    English language
    sale 15% off
ASTM
ASTM D5928-23(Practice)
Standard Practice for Screening of Waste for Radioactivity

SIGNIFICANCE AND USE
5.1 Most facilities disposing or using waste materials are prohibited from handling wastes that contain radioactive materials. This practice provides the user a rapid method for screening waste material for the presence or absence of radioactivity at user-established levels that consider background radiation and the intended use of the screening method. It is important to these facilities to be able to verify generator-supplied information in regard to radiation and to meet worker health and safety needs.
SCOPE
1.1 This practice covers the screening for α–, β–, and γ radiation above ambient background levels or user-defined criteria, or both, in liquid, sludge, or solid waste materials.  
1.2 This practice is intended to be a gross screening method for determining the presence or absence of radioactive materials in liquid, sludge, or solid waste materials. It is not intended to replace more sophisticated quantitative analytical techniques, but to provide a method for rapidly screening samples for radioactivity above ambient background levels or user-defined criteria, or both, for facilities prohibited from handling radioactive waste.  
1.3 This practice may or may not be suitable for applications such as site assessments and remediation activities, depending on the data quality objectives or intended use.  
1.4 The values stated in SI units are to be regarded as the 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 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.

  • Standard
    3 pages
    English language
    sale 15% off
  • Standard
    3 pages
    English language
    sale 15% off
ASTM
ASTM E481-23(Practice)
Standard Practice for Measuring Neutron Fluence Rates by Radioactivation of Cobalt and Silver

SIGNIFICANCE AND USE
3.1 This practice uses one monitor (cobalt) with a nearly 1/v absorption cross-section curve and a second monitor (silver) with a large resonance peak so that its resonance integral is large compared to its thermal cross section. The pertinent data for these two reactions are given in Table 1. The equations are based on the Westcott formalism ((2, 3) and Practice E261) and determine a Westcott 2200 m/s neutron fluence rate nv0 and the Westcott epithermal index parameter  . References (4-6) contain a general discussion of the two-reaction test method. In this practice, the absolute activities of both cobalt and silver monitors are determined. This differs from the test method in the references wherein only one absolute activity is determined.  (A) The numbers in parentheses following given values are the uncertainty in the last digit(s) of the value; 0.729 (8) means 0.729 ± 0.008, 70.8(1) means 70.8 ± 0.1.(B) The decay constant, λ, is defined as ln(2) / t1/2 with units of sec–1, where t1/2 is the nuclide half-life in seconds.(C) Calculated using Eq 10.(D) In Fig. 1, Θ = 4ErkT/AΓ2 = 0.2 corresponds to the value for 109Ag for T = 293 K, ∑r = N0σr,max,T=0Kσr,max,T=0K = 31138.03 barn at 5.19 eV (13). The value of σr,max,T=0K = 31138.03 barns is calculated using the Breit-Wigner single-level resonance formula  where the 109Ag atomic mass is A = 108.9047558 amu (14), the ENDF/B-VIII.0 (MAT = 4731) (13) resonance parameters are: resonance total width Γ = 0.1427333 eV, formation neutron width Γn = 0.0127333 eV, and radiative/decay width Γγ = 0.13 eV, with a resonance spin J=1, and the statistical spin factor  where s1 = 1/2 and s2 = 1/2 are the spins of the two particles (neutron and 109Ag ground state (15)) forming resonance.  
3.2 The advantages of this approach are the elimination of four difficulties associated with the use of cadmium: (1) the perturbation of the field by the cadmium; (2) the inexact cadmium cut-off energy; (3) the low melting temperature of cadmium; a...
SCOPE
1.1 This practice covers a suitable means of obtaining the thermal neutron fluence rate, or fluence, in nuclear reactor environments where the use of cadmium, as a thermal neutron shield as described in Test Method E262, is undesirable for reasons such as potential spectrum perturbations or due to temperatures above the melting point of cadmium.  
1.2 The reaction 59Co(n,γ )60Co results in a well-defined gamma emitter having a half-life of 5.2711 years2 (8)3 (1).4 The reaction 109Ag(n,γ)110mAg results in a nuclide with a well-known, complex decay scheme with a half-life of 249.78 (2) days (1). Both cobalt and silver are available either in very pure form or alloyed with other metals such as aluminum. A reference source of cobalt in aluminum alloy to serve as a neutron fluence rate monitor wire standard is available from the National Institute of Standards and Technology (NIST) as Standard Reference Material (SRM) 953.5 The competing activities from neutron activation of other isotopes are eliminated, for the most part, by waiting for the short-lived products to die out before counting. With suitable techniques, thermal neutron fluence rate in the range from 108 cm−2·s−1 to 3 × 1015 cm−2·s−1 can be measured. Two calculational practices are described in Section 9 for the determination of neutron fluence rates. The practice described in 9.3 may be used in all cases. This practice describes a means of measuring a Westcott neutron fluence rate in 9.2 (Note 1) by activation of cobalt- and silver-foil monitors (see Terminology E170). For the Wescott Neutron Fluence Convention method to be applicable, the measurement location must be well moderated and be well represented by a Maxwellian low-energy distribution and an (1/E) epithermal distribution. These conditions are usually only met in positions surrounded by hydrogenous moderator without nearby strongly multiplying or absorbing materials.
Note 1: Westcott fluence rate    ...

  • Standard
    7 pages
    English language
    sale 15% off
  • Standard
    7 pages
    English language
    sale 15% off
ASTM
ASTM D3648-23(Practice)
Standard Practices for the Measurement of Radioactivity

SIGNIFICANCE AND USE
5.1 This practice was developed for the purpose of summarizing the various generic radiometric techniques, equipment, and practices that are used for the measurement of radioactivity.
SCOPE
1.1 These practices cover a review of the accepted counting practices currently used in radiochemical analyses. The practices are divided into four sections:    
Section    
General Information  
6 – 11  
Alpha Counting  
12 – 22  
Beta Counting  
23 – 33  
Gamma Counting  
34 – 41  
1.2 The general information sections contain information applicable to all types of radioactive measurements, while each of the other sections is specific for a particular type of radiation.  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 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.  
1.5 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.

  • Standard
    28 pages
    English language
    sale 15% off
ASTM
ASTM E266-23(Test Method)
Standard Test Method for Measuring Fast-Neutron Reaction Rates by Radioactivation of Aluminum

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 determination of fast-neutron fluence rate with threshold detectors.  
5.3 Pure aluminum in the form of foil or wire is readily available and easily handled. 27Al has an abundance of 100 % (1).3  
5.4 24Na has a half-life of 14.958 (2)4 h (2) and emits gamma rays with energies of 1.368630 (5) and 2.754049 (13) MeV (2).  
5.5 Fig. 1 shows a plot of the International Reactor Dosimetry and Fusion File (IRDFF-II) cross section (3, 4) versus neutron energy for the fast-neutron reaction  27Al(n,α) 24Na (3) along with a comparison to the current experimental database (5, 6). While the RRDF-2008 and IRDFF-1.05 cross sections extend from threshold up to 60 MeV, due to considerations of the available validation data, the energy region over which this standard recommends use of this cross section for reactor dosimetry applications only extends from threshold at ~4.25 MeV up to 20 MeV. This figure is for illustrative purposes and is used to indicate the range of response of the  27Al(n,α) reaction. Refer to Guide E1018 for recommended sources for the tabulated dosimetry cross sections.
FIG. 1 27Al(n,α)24Na Cross Section, from IRDFF-II Library, with EXFOR Experimental Data  
5.6 Two competing activities, 28Al (2.25 (2) minute half-life) and 27Mg (9.458 (12) minute half-life), are formed in the reactions 27Al(n,γ)28Al and 27Al(n,p)27Mg, respectively, but these can be eliminated by waiting 2 h before counting.
SCOPE
1.1 This test method covers procedures measuring reaction rates by the activation reaction  27Al(n,α)24Na.  
1.2 This activation reaction is useful for measuring neutrons with energies above approximately 6.5 MeV and for irradiation times up to about two days (for longer irradiations, or when there are significant variations in reactor power during the irradiation, see Practice E261).  
1.3 With suitable techniques, fission-neutron fluence rates above 106 cm−2·s−1 can be determined.  
1.4 Detailed procedures for other fast neutron detectors are referenced in Practice E261.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 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.

  • Standard
    4 pages
    English language
    sale 15% off
  • Standard
    4 pages
    English language
    sale 15% off