ASTM C760-90(2020)

Standard Test Methods for Chemical and Spectrochemical Analysis of Nuclear-Grade Silver-Indium-Cadmium Alloys

SIGNIFICANCE AND USE
3.1 Silver-indium-cadmium alloy is used as a control material in nuclear reactors. In order to be suitable for this purpose, the material must meet the specifications for assay and impurity content. These test methods are designed to show whether or not a given material meets the specifications as given in Specification C752.  
3.1.1 An assay is performed to determine whether the material has the chemical composition specified.  
3.1.2 The impurity content is determined to ensure that the maximum concentration limit of impurities is not exceeded.
SCOPE
1.1 These test methods cover procedures for the chemical and spectrochemical analysis of nuclear grade silver-indium-cadmium (Ag-In-Cd) alloys to determine compliance with specifications.  
1.2 The analytical procedures appear in the following order:    
Sections  
Silver, Indium, and Cadmium by a Titration Method  
7 – 15  
Trace Impurities by Carrier-Distillation Spectro-
chemical Method  
16 – 22  
1.3 The values stated in SI units are to be regarded as the 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. For specific hazard and precautionary statements, see Section 5 and Practices E50.  
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.

General Information

• Status: Published
• Publication Date: 31-Dec-2019
• ICS: 77.040.30 - Chemical analysis of metals
• Technical Committee: C26 - Nuclear Fuel Cycle
• Drafting Committee: C26.03 - Neutron Absorber Materials Specifications

Relations

• Replaces: ASTM C760-90(2015) - Standard Test Methods for Chemical and Spectrochemical Analysis of Nuclear-Grade Silver-Indium-Cadmium Alloys
• Effective Date: 01-Jan-2020
• Refers: ASTM C752-18 - Standard Specification for Nuclear-Grade Silver-Indium-Cadmium Alloy
• Effective Date: 01-Jun-2018
• Refers: ASTM E50-17 - Standard Practices for Apparatus, Reagents, and Safety Considerations for Chemical Analysis of Metals, Ores, and Related Materials
• Effective Date: 01-Sep-2017
• Refers: ASTM E50-11(2016) - Standard Practices for Apparatus, Reagents, and Safety Considerations for Chemical Analysis of Metals, Ores, and Related Materials
• Effective Date: 01-Aug-2016
• Refers: ASTM C752-13(2016) - Standard Specification for Nuclear-Grade Silver-Indium-Cadmium Alloy
• Effective Date: 01-Apr-2016
• Refers: ASTM C752-13 - Standard Specification for Nuclear-Grade Silver-Indium-Cadmium Alloy
• Effective Date: 01-Feb-2013
• Refers: ASTM E50-11 - Standard Practices for Apparatus, Reagents, and Safety Considerations for Chemical Analysis of Metals, Ores, and Related Materials
• Effective Date: 15-Oct-2011
• Refers: ASTM C752-03(2010) - Standard Specification for Nuclear-Grade Silver-Indium-Cadmium Alloy
• Effective Date: 01-Mar-2010
• Refers: ASTM D1193-06 - Standard Specification for Reagent Water
• Effective Date: 01-Mar-2006
• Refers: ASTM E50-00(2005) - Standard Practices for Apparatus, Reagents, and Safety Considerations for Chemical Analysis of Metals, Ores, and Related Materials
• Effective Date: 01-May-2005
• Refers: ASTM C752-03 - Standard Specification for Nuclear-Grade Silver-Indium-Cadmium Alloy
• Effective Date: 10-Jul-2003
• Refers: ASTM E50-00 - Standard Practices for Apparatus, Reagents, and Safety Considerations for Chemical Analysis of Metals, Ores, and Related Materials
• Effective Date: 10-Nov-2000
• Refers: ASTM D1193-99e1 - Standard Specification for Reagent Water
• Effective Date: 10-Feb-1999
• Refers: ASTM D1193-99 - Standard Specification for Reagent Water
• Effective Date: 10-Feb-1999
• Refers: ASTM C752-88(1997) - Standard Specification for Nuclear-Grade Silver-Indium-Cadmium Alloy
• Effective Date: 10-May-1997

Overview

ASTM C760-90(2020) is the internationally recognized standard for performing chemical and spectrochemical analysis of nuclear-grade silver-indium-cadmium (Ag-In-Cd) alloys. These alloys are critically important as control materials in nuclear reactors, where precise composition and low impurity levels are a necessity for reliable, safe operation. This standard specifies test methods that ensure the alloy meets the chemical composition requirements and impurity limits defined in ASTM C752, supporting quality control and regulatory compliance within the nuclear industry.

Key procedures outlined in ASTM C760-90(2020) include:

• Titration methods for determining levels of silver, indium, and cadmium.
• Spectrochemical (carrier-distillation) methods for analyzing trace impurities.

All values and measurements are reported in SI units, aligning with global best practices.

Key Topics

• Purpose: Verifies that Ag-In-Cd alloys used as nuclear reactor control materials meet stringent specifications for composition and impurity content.
• Assay Determination: Tests confirm that silver, indium, and cadmium concentrations match required values-essential for neutron absorption performance in reactors.
• Impurity Limits: Ensures that extraneous elements or substances do not exceed levels which could compromise material integrity or reactor operation.
• Test Methods:
  • Chemical Analysis (Titration): Quantitative precipitation and complexometric titration techniques are employed for primary element assay.
  • Spectrochemical Analysis: Carrier-distillation arc spectrography is applied for trace impurity detection and quantification.
• Safety Considerations: Users must observe stringent laboratory practices to manage hazards associated with handling heavy metals and corrosive chemicals, as referenced in related ASTM safety procedures.

Applications

The analytical methods described in ASTM C760-90(2020) are essential for:

• Quality Assurance in Nuclear Manufacturing: Ensuring nuclear-grade control rod alloys meet composition and purity requirements for safe reactor operation.
• Materials Qualification: Verifying conformity with ASTM C752 specifications prior to use in critical nuclear environments.
• Regulatory Compliance: Providing documented evidence for auditors and regulatory authorities regarding material integrity and suitability.
• Research and Development: Developing and verifying new alloy batches, quality improvements, or alternative control rod compositions for enhanced performance.
• Failure Analysis: Investigating and diagnosing materials-related issues in nuclear component performance.

By following ASTM C760, laboratories can provide reliable, reproducible results that underpin the trust in nuclear reactor control materials.

Related Standards

For effective implementation of ASTM C760-90(2020), familiarity with these related standards is beneficial:

• ASTM C752 – Specification for Nuclear-Grade Silver-Indium-Cadmium Alloy: The referenced document providing detailed compositional requirements.
• ASTM D1193 – Specification for Reagent Water: Guidance for water quality used in analysis.
• ASTM E50 – Practices for Apparatus, Reagents, and Safety for Chemical Analysis: Safety and equipment protocols for the laboratory environment.
• ASTM E115 – (Withdrawn) Practice for Photographic Processing in Spectrographic Analysis: Refers to photographic development of spectrochemical analysis plates.
• ISO and NIST methods for emission spectroscopy and analytical chemistry may provide supplementary guidance.

Adhering to these standards ensures comprehensive quality, safety, and technical rigor for nuclear-grade Ag-In-Cd alloy analysis, reinforcing confidence in both materials and analytical results.

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Keywords: ASTM C760, nuclear-grade silver-indium-cadmium alloys, chemical analysis, spectrochemical analysis, nuclear reactor materials, control rods, impurity detection, alloy assay, quality assurance, ASTM standards.

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: C760 − 90 (Reapproved 2020)
Standard Test Methods for
Chemical and Spectrochemical Analysis of Nuclear-Grade
Silver-Indium-Cadmium Alloys
This standard is issued under the fixed designation C760; 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 erations for Chemical Analysis of Metals, Ores, and
Related Materials
1.1 These test methods cover procedures for the chemical
E115Practice for Photographic Processing in Optical Emis-
and spectrochemical analysis of nuclear grade silver-indium-
sion Spectrographic Analysis (Withdrawn 2002)
cadmium (Ag-In-Cd) alloys to determine compliance with
specifications. 2.2 Other Document:
NBS Circular 602
1.2 Theanalyticalproceduresappearinthefollowingorder:
Sections
3. Significance and Use
Silver, Indium, and Cadmium by a Titration Method 7–15
Trace Impurities by Carrier-Distillation Spectro- 16–22
3.1 Silver-indium-cadmium alloy is used as a control mate-
chemical Method
rial in nuclear reactors. In order to be suitable for this purpose,
1.3 The values stated in SI units are to be regarded as the
the material must meet the specifications for assay and impu-
standard.
rity content. These test methods are designed to show whether
1.4 This standard does not purport to address all of the
or not a given material meets the specifications as given in
safety concerns, if any, associated with its use. It is the
Specification C752.
responsibility of the user of this standard to establish appro-
3.1.1 An assay is performed to determine whether the
priate safety, health, and environmental practices and deter-
material has the chemical composition specified.
mine the applicability of regulatory limitations prior to use.
3.1.2 The impurity content is determined to ensure that the
Forspecifichazardandprecautionarystatements,seeSection5
maximum concentration limit of impurities is not exceeded.
and Practices E50.
1.5 This international standard was developed in accor-
4. Purity of Reagents
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
4.1 Reagent grade chemicals shall be used in all tests.
Development of International Standards, Guides and Recom-
Unlessotherwiseindicated,itisintendedthatallreagentsshall
mendations issued by the World Trade Organization Technical
conform to the specifications of the Committee on Analytical
Barriers to Trade (TBT) Committee.
Reagents of the American Chemical Society, where such
specifications are available. Other grades may be used, pro-
2. Referenced Documents
vided it is first ascertained that the reagent is of sufficiently
2.1 ASTM Standards: high purity to permit its use without lessening the accuracy of
the determination.
C752 Specification for Nuclear-Grade Silver-Indium-
Cadmium Alloy
4.2 Purity of Water—Unless otherwise indicated, references
D1193Specification for Reagent Water
towatershallbeunderstoodtomeanreagentwaterconforming
E50Practices for Apparatus, Reagents, and Safety Consid-
to Specification D1193.
These test methods are under the jurisdiction of ASTM Committee C26 on
Nuclear Fuel Cycle and are the direct responsibility of Subcommittee C26.03 on The last approved version of this historical standard is referenced on
Neutron Absorber Materials Specifications. www.astm.org.
Current edition approved Jan. 1, 2020. Published January 2020. Originally Available from National Institute of Standards and Technology (NIST), 100
approved in 1971. Last previous edition approved in 2015 as C760–90(2015). Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http://www.nist.gov.
DOI: 10.1520/C0760-90R20. Reagent Chemicals, American Chemical Society Specifications, American
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Chemical Society, Washington, DC. For suggestions on the testing of reagents not
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM listed by the American Chemical Society, see Analar Standards for Laboratory
Standards volume information, refer to the standard’s Document Summary page on Chemicals,BDHLtd.,Poole,Dorset,U.K.andthe United States Pharmacopeia and
the ASTM website. National Formulary,U.S.PharmacopeialConvention,Inc.(USPC),Rockville,MD.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C760 − 90 (2020)
5. Hazards 10.3 Glass pH Electrode—Standard type.
5.1 Properprecautionsshouldbetakentopreventinhalation 10.4 Chloride Specific Ion Electrode.
or ingestion of heavy element (silver, indium, or cadmium)
10.5 Expanded Scale pH/millivolt Meter.
powder or dust during handling.
5.2 Workers should observe precautions as specified in 11. Reagents
vendor-supplied Material Safety Data Sheets (MSDS).
11.1 Ammonium Hydroxide (sp gr 0.90)—Concentrated am-
monium hydroxide (NH OH).
6. Sampling
11.2 Buffer Solution, pH4—0.5 M sodium acetate—0.5 M
6.1 Suggestions for sampling this alloy are given in Speci-
acetic acid.
fication C752.
11.3 Cadmium (Cd)—Metal, >99.99% pure.
SILVER, INDIUM, AND CADMIUM BY A TITRATION
11.4 Ethylenediaminetetraacetate Dihydrate Disodium Salt
METHOD
(EDTA) Solution (0.01000 M)—Weigh 3.722 6 0.001 g of
EDTAintoasmallplasticbeaker.Dissolvewithwater,transfer
7. Scope
quantitativelytoa1-Lvolumetricflask,andmakeuptovolume
7.1 This test method is applicable to the determination of
with water.Transfer the solution to a plastic storage bottle. Do
silver, indium, and cadmium in alloys of approximately 80%
not allow the EDTA solution to stand in contact with glass
silver, 15% indium, and 5% cadmium used in nuclear reactor
containers.
6,7
control rod applications. The titrimetric methods presented
11.5 Indium (In)—Metal, >99.99% pure.
will yield results with a bias of the order of 0.1%.
11.6 Nitric Acid (sp gr 1.42)—Concentrated nitric acid
7.2 This international standard was developed in accor-
(HNO ).
dance with internationally recognized principles on standard- 3
ization established in the Decision on Principles for the
11.7 PAN Indicator Solution (0.1% PAN in Methanol)—
Development of International Standards, Guides and Recom-
Dissolve 100 mg of 1-(2-pyridylazo)-2-naphthol in 100 mLof
mendations issued by the World Trade Organization Technical
methyl alcohol and mix until completely dissolved.
Barriers to Trade (TBT) Committee.
11.8 Silver (Ag)—Metal, >99.99% pure.
8. Summary of Test Method 11.9 Sodium Chloride (NaCl).
8.1 Aweighed sample is dissolved in nitric acid and diluted
11.10 Sodium Chloride Solution (0.0500 M)—Dry sodium
to a known volume, and aliquots are removed for analysis. chloride (NaCl) at 120°C, in a weighing bottle, to a constant
Silver is determined first by titrating with standardized sodium
weight and cool to room temperature in a desiccator. Weigh
chloride solution to the potentiometric endpoint indicated by a 2.922 6 0.001 g of the dried NaCl into a small plastic beaker.
chloride-selective ion electrode. Following the silver titration,
Dissolve in water, quantitatively transfer to a 1-L volumetric
the solution is boiled to coagulate the silver chloride. The pH flask, and make up to volume with water.
isadjustedto2.5andtheindiumcontentistitratedwithEDTA,
using PAN (1-(2-pyridylazo)-2-naphthol) indicator. The pH is 12. Standardization
thenraisedto6.0andthecadmiumistitratedwithEDTAusing
12.1 Silver-Indium-Cadmium Calibration Standard:
the same indicator. The entire process requires approximately
12.1.1 Clean approximately 8.0 g of silver metal, 1.5 g of
20 min per aliquot, exclusive of sample weighing and disso-
indium metal, and 0.5 g of cadmium metal with an organic
lution.
solvent and air dry.
12.1.2 Weigh each metal accurately and transfer to a
9. Interferences
100-mL beaker.
9.1 Nointerferenceshavebeenobservedfromanyelements
12.1.3 Add sufficient water to cover the metal pieces and
normally encountered as impurities in nuclear grade silver-
add HNO (sp gr 1.42) dropwise until dissolution is complete.
indium-cadmiumalloyovertheconcentrationrangesexpected.
12.1.4 Transfer quantitatively to a 100-mLvolumetric flask
and dilute to volume with water.
10. Apparatus
12.2 Calibration of NaCl and EDTA Titrants:
10.1 Burets, precision, two, 25-mL capacity, preferably
12.2.1 Pipet 10 mL of the calibration standard into a
Schellbach type with TFE-fluorocarbon stopcock and auto-
100-mL volumetric flask and dilute to volume with water.
matic zero. They shall be certified or tested to conform with
(Retain this solution as a working standard.)
tolerances specified in NBS Circular 602.
12.2.2 Pipet 10 mL of the diluted standard into a 100-mL
10.2 Reference Electrode—Saturated calomel electrode.
beaker and adjust the volume to about 25 mL with water.
12.2.3 Adjust the pH to approximately 1 using NH OH (sp
gr 0.90).
Cheng, K. L., “Complexometric Titration of Indium,” Analytical Chemistry,
12.2.4 Place a TFE-fluorocarbon-coated stirring bar in the
Vol 27, 1955, p. 1582.
solution and insert the chloride specific ion electrode and the
Cheng, K. L., “Complexometric Titration of Copper and Other Metals in a
Mixture,” Analytical Chemistry, Vol 30, 1958, p. 243. reference electrode.
C760 − 90 (2020)
12.2.5 StiratamoderaterateandtitratethesilverwithNaCl 15. Precision and Bias
solution. Record millivolt readings versus volume added.
15.1 Precision—The estimated standard deviation for a
Allow sufficient time for equilibrium readings to be attained.
single measurement of each element is 0.03% for silver,
12.2.6 The titration end point is taken as the termination of
indium, and cadmium.
the rapidly rising segment of the millivolt versus volume
15.2 Bias—The estimated bias, measured using a known
titration curve.
80% Ag-15% In-5% Cd alloy, is as follows: Ag,−0.02%;
12.2.7 Adjust to pH 2.5 6 0.2 by dropwise addition of
In,+0.09%; Cd,−0.03%, absolute.
acetate buffer solution (pH4).
12.2.8 Remove the electrodes and rinse thoroughly to avoid
TRACE IMPURITIES BY
loss of indium and cadmium.
CARRIER–DISTILLATION
12.2.9 Heat the solution to boiling on a hotplate until the
SPECTRO
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