ASTM D7938-21
(Practice)Standard Practice for Sampling of C-14 in Gaseous Effluents
Standard Practice for Sampling of C-14 in Gaseous Effluents
SIGNIFICANCE AND USE
5.1 This practice was developed4 for the purpose of sampling gaseous effluent streams from a facility that releases 14C in either organic or inorganic forms.
5.1.1 For many years 14C was not included in gaseous and liquid effluent measurements used for effluent dose calculations at nuclear power facilities. U.S. NRC Regulatory Guide 1.21 now requires 14C analysis (either estimated by calculation or actual measurement) and its impact on annual dose in the environs of nuclear plants be evaluated. Based on the revisions to the Regulatory Guide and NRC guidance to licensees, 14C activity will need to be reported and evaluated for dose contribution based on the activity concentration and chemical form of the 14C in the release.
5.2 While 14C releases may be estimated, the measurement of actual 14C emissions provides a more reliable and accurate means of reporting emissions. The chemical form of 14C that yields the greatest dose significance due to uptake by living organisms is the inorganic form. Thus the distribution of 14C chemical forms in plant effluents is important in assessing the overall dose impact.
5.3 Use of this sampling practice has identified that for pressurized water reactors (PWRs) >90 % of all 14C released may be in the organic form during operation, and for boiling water reactors (BWRs) 14C released may be in the organic form during operation.
5.3.1 Some power plants have catalytic hydrogen recombiners in the waste gas processing system. These can also oxidize organic carbon to CO2, increasing the percentage of 14CO2 in the effluent release.
5.3.2 During refueling outages, oxidizing conditions exist in the reactor cavity due to air saturation and radiolytic reactions by the nuclear fuel. The combination of these two effects has been shown to increase the 14CO2 content of the sampled atmosphere inside the containment building.
5.4 The sampling methodology described in this practice is not capable of discriminating between different org...
SCOPE
1.1 The intended use of this practice is for sampling of gasses containing 14C in inorganic, organic or particulate forms. This sampling practice captures the 14C in a media that can be submitted to a laboratory for analysis, typically by liquid scintillation counting (LSC)
1.2 This practice does not include the needed steps for the liberation of 14C from the media on which it was adsorbed or those for the preparation for LSC sample preparation in the laboratory prior to liquid scintillation analysis. This practice does not include the methodology used to analyze the prepared samples by LSC.
1.3 The overall 14C analytical detection capability is impacted by a number of factors including the volume sampled, the method used to desorb the 14C from the media, and the analytical method used the measure 14C from the media. This practice only directly addresses the volume of the gas stream from which any present 14C would be adsorbed.
1.4 The values stated in pCi units are to be regarded as standard given the reporting requirements of the U.S. NRC Regulatory Guide 1.21. The Bq values given in parenthesis are mathematical conversions to SI units that are provided for information only and are not considered standard. Other values stated in SI units are to be regarded as 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.
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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: D7938 − 21
Standard Practice for
1
Sampling of C-14 in Gaseous Effluents
This standard is issued under the fixed designation D7938; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
2
1.1 The intended use of this practice is for sampling of 2.1 ASTM Standards:
14
D1129 Terminology Relating to Water
gasses containing C in inorganic, organic or particulate
14
D7282 Practice for Set-up, Calibration, and Quality Control
forms. This sampling practice captures the C in a media that
of Instruments Used for Radioactivity Measurements
can be submitted to a laboratory for analysis, typically by
D7902 Terminology for Radiochemical Analyses
liquid scintillation counting (LSC)
3
2.2 U.S. NRC Publications:
1.2 This practice does not include the needed steps for the
U.S. NRC Regulatory Guide 1.21 “Measuring, Evaluating,
14
liberation of C from the media on which it was adsorbed or
and Reporting Radioactive Material in Liquid and Gas-
those for the preparation for LSC sample preparation in the
eous Effluents and Solid Waste,” revision 2, June 2009
laboratory prior to liquid scintillation analysis. This practice
does not include the methodology used to analyze the prepared
3. Terminology
samples by LSC.
3.1 Definitions:
14
1.3 The overall C analytical detection capability is im- 3.1.1 For definitions of terms used in this standard, refer to
pacted by a number of factors including the volume sampled, Terminologies D1129 and D7902.
14
the method used to desorb the C from the media, and the 3.2 Definitions of Terms Specific to This Standard:
14 14 14
analytical method used the measure C from the media. This 3.2.1 organic C, n—any gaseous, chemical C form
practice only directly addresses the volume of the gas stream (including CO) that is not particulate and not CO .
2
14
from which any present C would be adsorbed. 3.2.1.1 Discussion—Although no specific organic form is
determined, the major contributors are likely to be CH,C H ,
4 2 6
1.4 The values stated in pCi units are to be regarded as
C H , CO, and C H .
2 4 2 2
standard given the reporting requirements of the U.S. NRC
14 14
3.2.2 inorganic C, n—the gaseous, chemical form of C
Regulatory Guide 1.21. The Bq values given in parenthesis are
as CO .
mathematical conversions to SI units that are provided for 2
3.2.2.1 Discussion—These chemical form categorizations
information only and are not considered standard. Other values
are based on U.S. NRC Regulatory Guide 1.21.
stated in SI units are to be regarded as standard.
1.5 This standard does not purport to address all of the
4. Summary of Practice
safety concerns, if any, associated with its use. It is the
4.1 A sample of a flowing gaseous stream is extracted at a
responsibility of the user of this standard to establish appro-
flowrateof30to3000mL/min.Thesampleisfilteredandsplit
priate safety, health, and environmental practices and deter-
into two parallel flow paths. One flow path is passed through a
mine the applicability of regulatory limitations prior to use. 14
furnace to convert all carbon to CO .This will yield a total C
2
1.6 This international standard was developed in accor-
content of the sample. The other flow path collects only the
dance with internationally recognized principles on standard-
CO fraction of the gaseous stream. This yields the inorganic
2
ization established in the Decision on Principles for the 14
C content of the gaseous stream. The calculated difference
Development of International Standards, Guides and Recom-
between the measured total and inorganic carbon content is the
mendations issued by the World Trade Organization Technical
organic content (U.S. NRC Regulatory Guide 1.21). The
Barriers to Trade (TBT) Committee. 14
concentration of C in the particulate matter may also be
determined.
1 2
This practice is under the jurisdiction of ASTM Committee D19 on Water and For referenced ASTM standards, visit the ASTM website, www.astm.org, or
is the direct responsibility of Subcommittee D19.04 on Methods of Radiochemical contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Analysis. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Dec. 15, 2021. Published February 2022. Originally the ASTM website.
3
approved in 2015. Last previous edition approved in 2015 as D7938 – 15. DOI: Available from U.S. Nuclear Regulatory Commission, W
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D7938 − 15 D7938 − 21
Standard Practice for
1
Sampling of C-14 in Gaseous Effluents
This standard is issued under the fixed designation D7938; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope
14
1.1 The intended use of this practice is for sampling of gasses containing C in inorganic, organic or particulate forms. This
14
sampling practice captures the C in a media that can be submitted to a laboratory for analysis, typically by liquid scintillation
counting (LSC)
14
1.2 This practice does not include the needed steps for the liberation of C from the media on which it was adsorbed or those
for the preparation for LSC sample preparation in the laboratory prior to liquid scintillation analysis. This practice does not include
the methodology used to analyze the prepared samples by LSC.
14
1.3 The overall C analytical detection capability is impacted by a number of factors including the volume sampled, the method
14 14
used to desorb the C from the media, and the analytical method used the measure C from the media. This practice only directly
14
addresses the volume of the gas stream from which any present C would be adsorbed.
1.4 The values stated in pCi units are to be regarded as standard given the reporting requirements of the U.S. NRC Regulatory
Guide 1.21. The Bq values given in parenthesis are mathematical conversions to SI units that are provided for information only
and are not considered standard. Other values stated in SI units are to be regarded as 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.
2. Referenced Documents
2
2.1 ASTM Standards:
D1129 Terminology Relating to Water
D7282 Practice for Set-up, Calibration, and Quality Control of Instruments Used for Radioactivity Measurements
D7902 Terminology for Radiochemical Analyses
3
2.2 U.S. NRC Publications:
U.S. NRC Regulatory Guide 1.21 “Measuring, Evaluating, and Reporting Radioactive Material in Liquid and Gaseous Effluents
and Solid Waste,” revision 2, June 2009
1
This practice is under the jurisdiction of ASTM Committee D19 on Water and is the direct responsibility of Subcommittee D19.04 on Methods of Radiochemical Analysis.
Current edition approved Dec. 15, 2015Dec. 15, 2021. Published February 2016February 2022. Originally approved in 2015. Last previous edition approved in 2015 as
D7938 – 15. DOI: 10.1520/D7938-15.10.1520/D7938-21.
2
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 the ASTM website.
3
Available from U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, http://www.nrc.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D7938 − 21
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms used in this standard, refer to Terminologies D1129 and D7902.
3.2 Definitions of Terms Specific to This Standard:
14 14
3.2.1 organic C, n—any gaseous, chemical C form (including CO) that is not particulate and not CO .
2
3.2.1.1 Discussion—
Although no specific organic form is determined, the major contributors are likely to be CH , C H , C H , CO, and C H .
4 2 6 2 4 2 2
14 14
3.2.2 inorganic C, n—the gaseous, chemical form of C as CO .
2
3.2.2.1 Discussion—
These chemical form categorizations are based on U.S. NRC Regulatory Guide 1.21.
4. Summary of Practice
4.1 A sample of a flowing gaseous stream is extracted at a flow rate of 30 to 3000 mL/min. The sample is filtered,filtered and split
14
into two parallel flow paths. One flow path is passed through a fu
...
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