ASTM C1475-17

Standard Guide for Determination of Neptunium-237 in Soil

SIGNIFICANCE AND USE
5.1 A soil sampling and analysis program provides a direct means of determining the concentration and distribution of radionuclides in soil. The presence and extent of neptunium-237 is of particular interest because it is one of the more mobile transuranics in terms of migration and plant uptake. Since soil is an integrator and a reservoir on long-lived radionuclides, and serves as an intermediary in several pathways of potential importance to humans, knowledge of the concentration of neptunium-237 in soil is essential.
SCOPE
1.1 This guide covers the determination of neptunium-237 in soil by means of radiochemical separations and alpha spectrometry. This guide provides options in the selection of sample preparation, separation, and measurement. Although neptunium-237 is not a component of global fallout, it is a product of production reactors and spent fuel processing. This guide is designed for analysis of ten grams of soil previously collected and treated in accordance with Practices C998 and C999. Larger-size samples of environmental soil may also be analyzed, as long as the concentrations of interferences such as uranium and thorium are at or near environmental concentrations. Depending on the choice of a sample dissolution method, all chemical forms of neptunium may not be completely solubilized. This guide should allow the determination of neptunium-237 concentrations from sub becquerel per gram levels to applicable standards depending on count time, sample size, detector efficiency, background, and tracer yield.  
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. Specific precautionary statements are given in Section 9.  
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.

General Information

• Status: Published
• Publication Date: 31-May-2017
• ICS: 13.080.10 - Chemical characteristics of soils
• Technical Committee: C26 - Nuclear Fuel Cycle
• Drafting Committee: C26.05 - Methods of Test

Relations

• Replaces: ASTM C1475-05(2010)e1 - Standard Guide for Determination of Neptunium-237 in Soil
• Effective Date: 01-Jun-2017
• Refers: ASTM C859-24 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Jan-2024
• Refers: ASTM C1001-19 - Standard Test Method for Radiochemical Determination of Plutonium in Soil by Alpha Spectroscopy
• Effective Date: 01-Nov-2019
• Refers: ASTM C1000-19 - Standard Test Method for Radiochemical Determination of Uranium Isotopes in Soil by Alpha Spectrometry
• Effective Date: 01-Nov-2019
• Refers: ASTM D4962-18 - Standard Practice for NaI(Tl) Gamma-Ray Spectrometry of Water
• Effective Date: 01-Oct-2018
• Refers: ASTM C1284-18 - Standard Practice for Electrodeposition of the Actinides for Alpha Spectrometry
• Effective Date: 01-Jun-2018
• Refers: ASTM D1890-15(2017) - Standard Test Method for Beta Particle Radioactivity of Water
• Effective Date: 15-Dec-2017
• Refers: ASTM D4962-17 - Standard Practice for NaI(Tl) Gamma-Ray Spectrometry of Water
• Effective Date: 01-Nov-2017
• Refers: ASTM C999-17 - Standard Practice for Soil Sample Preparation for the Determination of Radionuclides
• Effective Date: 01-Jun-2017
• Refers: ASTM C998-17 - Standard Practice for Sampling Surface Soil for Radionuclides
• Effective Date: 01-Jun-2017
• Refers: ASTM D1890-15 - Standard Test Method for Beta Particle Radioactivity of Water 
• Effective Date: 01-Jan-2015
• Refers: ASTM C859-14a - Standard Terminology Relating to Nuclear Materials
• Effective Date: 15-Jun-2014
• Refers: ASTM C859-14 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 15-Jan-2014
• Refers: ASTM C859-13a - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Jun-2013
• Refers: ASTM C859-13 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-May-2013

Overview

ASTM C1475-17: Standard Guide for Determination of Neptunium-237 in Soil provides comprehensive guidance for laboratories and professionals involved in the detection and quantification of neptunium-237 (Np-237) in environmental soil samples. Issued by ASTM International, this standard is essential for assessing sites with potential radionuclide contamination. It outlines standardized radiochemical separation and measurement techniques, emphasizing sample preparation, separation, and quantification using alpha spectrometry. Neptunium-237 is not a fallout radionuclide but a byproduct of nuclear reactors and spent fuel processing, making targeted analysis crucial in certain environmental and regulatory contexts.

Key Topics

• Sampling and Preparation: Relies on established protocols for soil collection and preparation, notably ASTM Practices C998 (surface soil sampling) and C999 (sample preparation for radionuclide determination).
• Radiochemical Separation: Describes methods for extracting neptunium-237 from soil via radiochemical techniques and extraction chromatography, optimizing for specificity even in the presence of uranium and thorium at environmental levels.
• Alpha Spectrometry: Details the use of alpha spectrometry to measure neptunium-237, with guidance on sample mounting using practices such as C1163 (neodymium fluoride co-precipitation) or C1284 (electrodeposition).
• Quality Control: Utilizes neptunium-239 as a radiometric yield monitor, ensuring accuracy through beta or gamma-ray counting methods.
• Interferences and Limitations: Identifies common interferences such as phosphates, uranium, and thorium, with recommended adjustments to minimize their impact on analytical results.
• Safety Considerations: Highlights the need to address chemical and radiological safety, particularly when handling hazardous reagents like hydrofluoric acid.

Applications

• Environmental Site Assessment: Used to evaluate radionuclide distribution and migration at sites impacted by nuclear reactor operations or fuel reprocessing, supporting risk assessment and remediation strategies.
• Regulatory Compliance: Facilitates compliance with environmental regulations governing radioactive contamination, ensuring data is reliable for decision-making by authorities and stakeholders.
• Research and Monitoring: Applied in long-term monitoring of environmental sites or scientific studies investigating the mobility, uptake, and environmental fate of transuranics, particularly neptunium-237.
• Soil Analysis Programs: Integral to comprehensive soil analysis programs as soil acts as an integrator and reservoir for long-lived radionuclides, impacting potential human exposure pathways.

Related Standards

Practitioners using ASTM C1475-17 often reference associated ASTM and industry standards for a complete analytical workflow:

• ASTM C998: Sampling Surface Soil for Radionuclides
• ASTM C999: Soil Sample Preparation for Radionuclide Determination
• ASTM C1000: Radiochemical Determination of Uranium Isotopes in Soil by Alpha Spectrometry
• ASTM C1001: Radiochemical Determination of Plutonium in Soil by Alpha Spectroscopy
• ASTM C1163: Mounting Actinides for Alpha Spectrometry Using Neodymium Fluoride
• ASTM C1284: Electrodeposition of Actinides for Alpha Spectrometry
• ASTM D1193: Specification for Reagent Water
• ASTM D1890: Test Method for Beta Radioactivity of Water
• ASTM D3084: Practice for Alpha-Particle Spectrometry of Water
• IEEE/ASTM SI-10: Standard for Use of the International System of Units (SI)

Practical Value

ASTM C1475-17 delivers a robust framework for the determination of neptunium-237 in soil, critical for environmental monitoring, health risk assessment, and regulatory compliance in nuclear and radiological contexts. By adhering to standardized procedures, laboratories can provide high-confidence data on neptunium-237 concentrations, supporting informed decision-making and public safety. The guide’s flexibility in sample preparation and detection techniques ensures it remains applicable in a variety of field and laboratory scenarios, reinforcing its value for professionals in radiochemistry, environmental science, and nuclear industry compliance.

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: C1475 − 17
Standard Guide for
Determination of Neptunium-237 in Soil
This standard is issued under the fixed designation C1475; 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
1.1 This guide covers the determination of neptunium-237
2.1 ASTM Standards:
in soil by means of radiochemical separations and alpha
C859 Terminology Relating to Nuclear Materials
spectrometry. This guide provides options in the selection of
C998 Practice for Sampling Surface Soil for Radionuclides
sample preparation, separation, and measurement. Although
C999 Practice for Soil Sample Preparation for the Determi-
neptunium-237 is not a component of global fallout, it is a
nation of Radionuclides
product of production reactors and spent fuel processing. This
C1000 Test Method for Radiochemical Determination of
guide is designed for analysis of ten grams of soil previously
Uranium Isotopes in Soil by Alpha Spectrometry
collected and treated in accordance with Practices C998 and
C1001 Test Method for Radiochemical Determination of
C999. Larger-size samples of environmental soil may also be
Plutonium in Soil by Alpha Spectroscopy
analyzed, as long as the concentrations of interferences such as
C1163 Practice for MountingActinides forAlpha Spectrom-
uranium and thorium are at or near environmental concentra-
etry Using Neodymium Fluoride
tions.Dependingonthechoiceofasampledissolutionmethod,
C1284 Practice for Electrodeposition of the Actinides for
all chemical forms of neptunium may not be completely
Alpha Spectrometry
solubilized. This guide should allow the determination of
C1317 Practice for Dissolution of Silicate or Acid-Resistant
neptunium-237 concentrations from sub becquerel per gram
Matrix Samples (Withdrawn 2001)
levels to applicable standards depending on count time, sample
C1342 Practice for Flux Fusion Sample Dissolution (With-
size, detector efficiency, background, and tracer yield.
drawn 2001)
1.2 The values stated in SI units are to be regarded as
C1387 Guide for the Determination of Technetium-99 in
standard. No other units of measurement are included in this
Soil
standard.
C1412 Practice for Microwave Oven Dissolution of Glass
1.3 This standard does not purport to address all of the
Containing Radioactive and Mixed Wastes (Withdrawn
safety concerns, if any, associated with its use. It is the
2001)
responsibility of the user of this standard to establish appro-
D1193 Specification for Reagent Water
priate safety and health practices and determine the applica-
D1890 Test Method for Beta Particle Radioactivity of Water
bility of regulatory limitations prior to use. Specific precau-
D3084 Practice for Alpha-Particle Spectrometry of Water
tionary statements are given in Section 9.
D4962 Practice for NaI(Tl) Gamma-Ray Spectrometry of
1.4 This international standard was developed in accor-
Water
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
2.2 Other Documents:
Development of International Standards, Guides and Recom-
IEEE/ASTM SI-10 Standard for the Use of the International
mendations issued by the World Trade Organization Technical
System of Units (SI): The Modern Metric System
Barriers to Trade (TBT) Committee.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
This guide is under the jurisdiction ofASTM Committee C26 on Nuclear Fuel contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Cycle and is the direct responsibility of Subcommittee C26.05 on Methods of Test. Standards volume information, refer to the standard’s Document Summary page on
CurrenteditionapprovedJune1,2017.PublishedJuly2017.Originallyapproved the ASTM website.
ɛ1 3
in 2000. Last previous edition approved in 2010 as C1475 – 05 (2010) . DOI: The last approved version of this historical standard is referenced on
10.1520/C1475-17. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1475 − 17
3. Terminology tee on Analytical Reagents of the American Chemical Society
where such specifications are available. Other grades may be
3.1 Except as otherwise defined herein, definitions of terms
used, provided it is first ascertained that the reagent is of
are as given in Terminology C859.
sufficiently high purity to permit its use without lessening the
4. Summary of Guide accuracy of the determination.
4.1 This guide may be used to determine neptunium-237 in
8.2 Purity of Water—Unless otherwise indicated, references
soil at potential release sites.Aneptunium-239 yield monitor is
to water shall be understood to mean reagent water as defined
added to the soil aliquot and the sample solubilized by one of
in Specification D1193.
several methods, such as those described in Guide C1387. The
8.3 Aluminum Nitrate Hydrate [Al(NO ) ·9H O].
neptunium is separated from the resulting solution using an 3 3 2
extraction chromatography column. A valence adjustment is
8.4 Aliphatic Quaternary Amine Extraction Chromatogra-
performed prior to loading the sample onto the conditioned
phy Resin.
chromatography column. The sample is passed through the
8.5 Ferrous Sulfamate [Fe(SO NH ) ], 1.0 M—Dissolve
column, which retains the neptunium in the +4 oxidation state. 3 2 2
38.8 g of sulfamic acid (NH SO H) and 11.6 g of iron powder
The column is washed to remove interferences and selectively
2 3
in approximately 150 mL of water. Stir while heating until
eluted with dilute acid. The samples are prepared for measure-
dissolved and then dilute to 200 mL with water. Prepare fresh
ment by neodymium fluoride co-precipitation or
electrodeposition, and the neptunium-237 content determined each week or keep under a nitrogen blanket to minimize
by alpha spectrometry. The neptunium-239 yield monitor is oxidation.
determined by beta or gamma-ray counting.
8.6 Hydrofluoric Acid (48 to 51 %)—Concentrated hydro-
fluoric acid (HF).
5. Significance and Use
5.1 A soil sampling and analysis program provides a direct 8.7 Iron Powder.
means of determining the concentration and distribution of
8.8 Nitric Acid (sp gr 1.42)—Concentrated nitric acid
radionuclides in soil. The presence and extent of neptunium-
(HNO ).
237isofparticularinterestbecauseitisoneofthemoremobile
transuranics in terms of migration and plant uptake. Since soil
8.9 Nitric Acid, 3.0 M—Add 189 mL of concentrated nitric
isanintegratorandareservoironlong-livedradionuclides,and
acid to 400 mLof water and dilute to 1.0 Lwith water and mix.
serves as an intermediary in several pathways of potential
8.10 2.5 M Nitric Acid-0.5 M Aluminum Nitrate—Dissolve
importance to humans, knowledge of the concentration of
187.6 g of aluminum nitrate in about 500 mLof water, add 159
neptunium-237 in soil is essential.
mL of concentrated nitric acid, and dilute to 1.0 L.
6. Interferences
8.11 0.02 M Nitric Acid-0.02 M Hydrofluoric Acid—Add
6.1 Phosphates present in the sample matrix will interfere
1.25 mLof concentrated nitric acid and 0.7 mLof concentrated
with the separation chemistry.Aluminum nitrate may be added
hydrofluoric acid to 800 mL of water and dilute to 1.0 L with
to the load solution to minimize this problem.
water and mix.
6.2 Highconcentrationsofuraniumorthoriumcanoverload
8.12 Radiometric Yield Tracer—Neptunium-239isnormally
the column, resulting in low recoveries of neptunium or
used as a yield monitor in the determination of neptunium-237.
spectral interferences. A preliminary separation may be re-
Where beta counting is used to determine the neptunium-239
quired to avoid spectral interference from uranium, see Test
yield, a relatively low amount of activity, for example, 5 to 15
Method C1000. The presence of uranium-233 and uranium-
Bq, is typically required to obtain the desired precision with a
234 could cause spectral interferences with the neptunium-237
60-min count duration. Another option is the addition of a
determination.
known quantity of americium-243, in secular equilibrium with
neptunium-239, directly to the sample. This approach has the
7. Apparatus
advantage of allowing the use of americium-243 solutions of
7.1 Apparatus for the sample dissolution and measurement
NIST-traceable activity. Where gamma-ray counting is used to
are identified within the selected test method.
determinetheneptunium-239yield,alargeramountofactivity,
7.2 Extraction Columns, with a bed volume of several
for example, 120 to 1200 Bq, may be required to obtain the
millilitres for the extraction chromatography resin.
desired precision with a 10-min count duration dependent on
the use of a NaI(TI) or HPGe detector. In this situation, it may
8. Reagents
8.1 Purity of Reagents—Reagent grade chemicals shall be
used in all tests. Unless otherwise indicated, it is intended that
Reagent Chemicals, American Chemical Society Specifications, American
all reagents shall conform to the specifications of the Commit-
...

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.
´1
Designation: C1475 − 05 (Reapproved 2010) C1475 − 17
Standard Guide for
Determination of Neptunium-237 in Soil
This standard is issued under the fixed designation C1475; 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.
ε NOTE—Editorial changes were made throughout in June 2010.
1. Scope
1.1 This guide covers the determination of neptunium-237 in soil by means of radiochemical separations and alpha
spectrometry. This guide provides options in the selection of sample preparation, separation, and measurement. Although
neptunium-237 is not a component of global fallout, it is a product of production reactors and spent fuel processing. This guide
is designed for analysis of ten grams of soil previously collected and treated in accordance with Practices C998 and C999.
Larger-size samples of environmental soil may also be analyzed, as long as the concentrations of interferences such as uranium
and thorium are at or near environmental concentrations. Depending on the choice of a sample dissolution method, all chemical
forms of neptunium may not be completely solubilized. This guide should allow the determination of neptunium-237
concentrations from sub becquerel per gram levels to applicable standards depending on count time, sample size, detector
efficiency, background, and tracer yield.
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. Specific precautionary statements are given in Section 89.
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.
2. Referenced Documents
2.1 ASTM Standards:
C859 Terminology Relating to Nuclear Materials
C998 Practice for Sampling Surface Soil for Radionuclides
C999 Practice for Soil Sample Preparation for the Determination of Radionuclides
C1000 Test Method for Radiochemical Determination of Uranium Isotopes in Soil by Alpha Spectrometry
C1001 Test Method for Radiochemical Determination of Plutonium in Soil by Alpha Spectroscopy
C1163 Practice for Mounting Actinides for Alpha Spectrometry Using Neodymium Fluoride
C1284 Practice for Electrodeposition of the Actinides for Alpha Spectrometry
C1317 Practice for Dissolution of Silicate or Acid-Resistant Matrix Samples (Withdrawn 2001)
C1342 Practice for Flux Fusion Sample Dissolution (Withdrawn 2001)
C1387 Guide for the Determination of Technetium-99 in Soil
C1412 Practice for Microwave Oven Dissolution of Glass Containing Radioactive and Mixed Wastes (Withdrawn 2001)
D1193 Specification for Reagent Water
D1890 Test Method for Beta Particle Radioactivity of Water
D3084 Practice for Alpha-Particle Spectrometry of Water
D4962 Practice for NaI(Tl) Gamma-Ray Spectrometry of Water
This guide is under the jurisdiction of ASTM Committee C26 on Nuclear Fuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods of Test.
Current edition approved June 1, 2010June 1, 2017. Published June 2010July 2017. Originally approved in 2000. Last previous edition approved in 20052010 as
ɛ1
C1475 – 05.C1475 – 05 (2010) . DOI: 10.1520/C1475-05R10E01.10.1520/C1475-17.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1475 − 17
2.2 Other Documents:
IEEE/ASTM SI-10 Standard for the Use of the International System of Units (SI): The Modern Metric System
3. Terminology
3.1 Except as otherwise defined herein, definitions of terms are as given in Terminology C859.
4. Summary of Guide
4.1 This guide may be used to determine neptunium-237 in soil at potential release sites. A neptunium-239 yield monitor is
added to the soil aliquot and the sample solubilized by one of several methods, such as those described in Guide C1387. The
neptunium is separated from the resulting solution using an extraction chromatography column. A valence adjustment is performed
prior to loading the sample onto the conditioned chromatography column. The sample is passed through the column, which retains
the neptunium in the +4 oxidation state. The column is washed to remove interferences and selectively eluted with dilute acid. The
samples are prepared for measurement by neodymium fluoride co-precipitation or electrodeposition, and the neptunium-237
content determined by alpha spectrometry. The neptunium-239 yield monitor is determined by beta or gamma-ray counting.
5. Significance and Use
5.1 A soil sampling and analysis program provides a direct means of determining the concentration and distribution of
radionuclides in soil. The presence and extent of neptunium-237 is of particular interest because it is one of the more mobile
transuranics in terms of migration and plant uptake. Since soil is an integrator and a reservoir on long-lived radionuclides, and
serves as an intermediary in several pathways of potential importance to humans, knowledge of the concentration of
neptunium-237 in soil is essential.
6. Interferences
6.1 Phosphates present in the sample matrix will interfere with the separation chemistry. Aluminum nitrate may be added to the
load solution to minimize this problem.
6.2 High concentrations of uranium or thorium can overload the column, resulting in low recoveries of neptunium or spectral
interferences. A preliminary separation may be required to avoid spectral interference from uranium, see Test Method C1000. The
presence of uranium-233 and uranium-234 could cause spectral interferences with the neptunium-237 determination.
7. Apparatus
7.1 Apparatus for the sample dissolution and measurement are identified within the selected test method.
7.2 Extraction Columns, with a bed volume of several millilitres for the extraction chromatography resin.
8. Reagents
8.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society where
such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high
purity to permit its use without lessening the accuracy of the determination.
8.2 Purity of Water—Unless otherwise indicated, references to water shall be understood to mean reagent water as defined in
Specification D1193.
8.3 Aluminum Nitrate Hydrate [Al(NO ) ·9H O].
3 3 2
8.4 Aliphatic Quaternary Amine Extraction Chromatography Resin.
8.5 Ferrous Sulfamate [Fe(SO NH ) ], 1.0M—Dissolve 38.8 g of sulfamic acid (NH SO H) and 11.6 g of iron powder in
3 2 2 2 3
approximately 150 mL of water. Stir while heating until dissolved and then dilute to 200 mL with water. Prepare fresh each week
or keep under a nitrogen blanket to minimize oxidation.
8.6 Hydrofluoric Acid (48 to 51 %)—Concentrated hydrofluoric acid (HF).
8.7 Iron Powder.
8.8 Nitric Acid (sp gr 1.42)—Concentrated nitric acid (HNO ).
8.9 Nitric Acid, 3.0M—Add 189 mL of concentrated nitric acid to 400 mL of water and dilute to 1.0 L with water and mix.
Prepacked columns of TEVA Resin from Eichrom Technologies, Inc., Lisle, IL, have been found to be satisfactory for this purpose.
Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed by
the American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National
Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.
C1475 − 17
8.10 2.5 M Nitric Acid-0.5 M Aluminum Nitrate—Dissolve 187.6 g of aluminum nitrate in about 500 mL of water, add 159 mL
of concentrated nitric acid, and dilute to 1.0 L.
8.11 0.02 M Nitric Acid-0.02 M Hydrofluoric Acid—Add 1.25 mL of concentrated nitric acid and 0.7 mL of concentrated
hydrofluoric acid to 800 mL of water and dilute to 1.0 L with water and mix.
8.12 Radiometric Yield Tracer—Neptunium-239 is normally used as a yield monitor in the determination of neptunium-237.
Where beta counting is used to determine the neptunium-239 yield, a relatively low amount of activity, for example, 5 to 15 Bq,
is typically required to obtain the desired precision with a 60-min count duration. Another option is the addition of a known
quantity of americium-243, in secular equilibrium with neptunium-239, directly to the sample. This approach has the advantag
...