ASTM C859-24

Standard Terminology Relating to Nuclear Materials

SCOPE
1.1 This terminology standard covers terms, definitions, descriptions of terms, nomenclature, and explanations of acronyms and symbols specifically associated with standards under the jurisdiction of Committee C26 on Nuclear Fuel Cycle. The content of this terminology standard may also be applicable to documents not under the jurisdiction of Committee C26, in which case this terminology standard may be referenced in those documents.  
1.2 While subcommittees within Committee C26 are free to only provide terms and definitions within individual standards, each subcommittee may request the addition of utilized terms and definitions to this terminology standard if it believes that such serves the broader interest of Committee C26 and the nuclear fuel cycle profession. Therefore, terms and definitions proposed for inclusion in Terminology C859 need not be used in more than one committee standard before being considered.  
1.3 In general, technical terms that are defined in common dictionaries would not also be defined in this terminology standard unless there is a need to emphasize a specific definition in making appropriate use of a Committee C26 standard.  
1.4 Subcommittee C26.10 (Nondestructive Assay) also has a terminology standard applicable to its standards: Terminology C1673.  
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-2023
• ICS: 01.040.27 - Energy and heat transfer engineering (Vocabularies)
• ICS: 27.120.30 - Fissile materials and nuclear fuel technology
• Technical Committee: C26 - Nuclear Fuel Cycle
• Drafting Committee: C26.01 - Editorial and Terminology

Relations

• Replaces: ASTM C859-23 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Jan-2024
• Referred By: ASTM C1387-23 - Standard Guide for the Determination of Technetium-99 in Soil
• Effective Date: 01-Jan-2024
• Referred By: ASTM C1163-14(2023) - Standard Practice for Mounting Actinides for Alpha Spectrometry Using Neodymium Fluoride
• Effective Date: 01-Jan-2024
• Referred By: ASTM C1572/C1572M-23 - Standard Guide for Dry Lead Glass and Oil-Filled Lead Glass Radiation Shielding Window Components for Remotely Operated Facilities
• Effective Date: 01-Jan-2024
• Referred By: ASTM C1733-21 - Standard Test Method for Distribution Coefficients of Inorganic Species by Batch Method
• Effective Date: 01-Jan-2024
• Referred By: ASTM C1254-18 - Standard Test Method for Determination of Uranium in Mineral Acids by X-Ray Fluorescence
• Effective Date: 01-Jan-2024
• Referred By: ASTM C1457-18 - Standard Test Method for Determination of Total Hydrogen Content of Uranium Oxide Powders and Pellets by Carrier Gas Extraction
• Effective Date: 01-Jan-2024
• Referred By: ASTM C1590-21 - Standard Practice for Alternate Actinide Calibration for Inductively Coupled Plasma-Mass Spectrometry
• Effective Date: 01-Jan-2024
• Referred By: ASTM C1001-19 - Standard Test Method for Radiochemical Determination of Plutonium in Soil by Alpha Spectroscopy
• Effective Date: 01-Jan-2024
• Referred By: ASTM C1725-17(2022) - Standard Guide for Hot Cell Specialized Support Equipment and Tools
• Effective Date: 01-Jan-2024
• Referred By: ASTM C1817-16 - Standard Test Method for The Determination of the Oxygen to Metal (O/M) Ratio in Sintered Mixed Oxide ((U, Pu)O<inf>2</inf>) Pellets by Gravimetry
• Effective Date: 01-Jan-2024
• Referred By: ASTM C784-20 - Standard Specification for Nuclear-Grade Aluminum Oxide-Boron Carbide Composite Pellets
• Effective Date: 01-Jan-2024
• Referred By: ASTM C996-20 - Standard Specification for Uranium Hexafluoride Enriched to Less Than 5&#x2009;%&#x2009;<sup > 235</sup>U
• Effective Date: 01-Jan-2024
• Referred By: ASTM C1062-23 - Standard Guide for Design, Fabrication, and Installation of Nuclear Fuel Dissolution Facilities
• Effective Date: 01-Jan-2024
• Referred By: ASTM C1009-21 - Standard Guide for Establishing and Maintaining a Quality Assurance Program for Analytical Laboratories Within the Nuclear Industry
• Effective Date: 01-Jan-2024

Overview

ASTM C859-24: Standard Terminology Relating to Nuclear Materials is an international standard developed by ASTM Committee C26 on Nuclear Fuel Cycle. This terminology standard provides authoritative definitions, nomenclature, acronyms, and symbols pertinent to nuclear materials, supporting consistency and clarity across technical documents and standards related to the nuclear fuel cycle. The standard plays a vital role in facilitating communication and interpretation among professionals working with nuclear fuel, radioactive waste management, and associated analytical methods.

Key Topics

ASTM C859-24 encompasses terminology for a wide array of concepts vital in nuclear materials science and technology, including:

• Nuclear Fuel Cycle: Definitions relevant to various stages such as fuel fabrication, irradiation, reprocessing, and waste disposal.
• Radiation and Radioactivity: Terms for types of radiation (alpha, beta, gamma, neutron), units of measurement (becquerel, gray, sievert), and biological effects.
• Analytical Methods: Standardized vocabulary for physical and chemical analysis, such as destructive analysis (DA), non-destructive assay (NDA), and calibration procedures.
• Materials and Waste Forms: Nomenclature for spent nuclear fuel types (e.g., aluminum-based spent fuel), waste forms, corrosion products, and high-level radioactive waste.
• Test Methods and Quality Assurance: Descriptions of leach tests, calibration and verification solutions, and concepts supporting measurement reliability.
• Facilities and Equipment: Definitions of facilities like hot cells, dry cask storage systems, canyons, and remote handling devices such as electro-mechanical manipulators.

Additionally, the standard offers explanations for commonly used acronyms and abbreviations, ensuring clarity in technical communication.

Applications

ASTM C859-24 is an essential reference for:

• Standards Development and Compliance: Assisting committees, developers, and regulators in harmonizing language used in nuclear fuel cycle standards and technical documents.
• Nuclear Industry Operations: Supporting nuclear fuel fabrication, handling, assay, and waste management by providing precise terminology, reducing ambiguity in procedures and reporting.
• Regulatory Documents and Reports: Useful in drafting, reviewing, and interpreting regulatory or safety documentation where accurate definitions are critical.
• Research and Education: Serving as a foundation for educational materials and research publications in nuclear engineering, radiology, and environmental sciences.
• International Collaboration: Improving understanding and collaboration across borders by standardizing terminology, especially for organizations referencing ASTM standards globally.

The standard’s flexible approach allows subcommittees to propose and include new terms as the profession evolves, ensuring relevance and comprehensive coverage.

Related Standards

For comprehensive application and understanding, ASTM C859-24 should be considered alongside other related ASTM standards and technical guides, such as:

• ASTM C1673: Terminology of C26.10 Nondestructive Assay Methods
• ASTM C1108: Test Method for Plutonium by Controlled-Potential Coulometry
• ASTM C1156: Guide for Establishing Calibration for a Measurement Method Used to Analyze Nuclear Fuel Cycle Materials

These documents further detail testing methods and terminology specific to nondestructive assays, plutonium analysis, and calibration, complementing the terminology foundation provided by ASTM C859-24.

---

Keywords: ASTM C859-24, nuclear materials, nuclear fuel cycle, radioactive waste, terminology, nuclear standards, Committee C26, radiation, nondestructive assay, analytical methods, calibration, hot cell, radioactive materials, waste management

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: C859 − 24
Standard Terminology Relating to
Nuclear Materials
This standard is issued under the fixed designation C859; 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 terminology standard covers terms, definitions, 2.1 ASTM Standards:
descriptions of terms, nomenclature, and explanations of acro- C1108 Test Method for Plutonium by Controlled-Potential
nyms and symbols specifically associated with standards under Coulometry
the jurisdiction of Committee C26 on Nuclear Fuel Cycle. The C1156 Guide for Establishing Calibration for a Measure-
content of this terminology standard may also be applicable to ment Method Used to Analyze Nuclear Fuel Cycle Mate-
documents not under the jurisdiction of Committee C26, in rials
which case this terminology standard may be referenced in C1673 Terminology of C26.10 Nondestructive Assay Meth-
those documents. ods
1.2 While subcommittees within Committee C26 are free to
3. Terminology
only provide terms and definitions within individual standards,
3.1 Definitions:
each subcommittee may request the addition of utilized terms
2 -2
absorbed dose, D, [L T ], n—absorbed dose is the mean
and definitions to this terminology standard if it believes that
energy imparted by ionizing radiation to a unit mass of
such serves the broader interest of Committee C26 and the
specified material.
nuclear fuel cycle profession. Therefore, terms and definitions
DISCUSSION—The SI unit for absorbed dose is the gray (Gy), defined
proposed for inclusion in Terminology C859 need not be used
as 1 J/kg.
in more than one committee standard before being considered.
abundance sensitivity, n—in methods of chemical analysis,
1.3 In general, technical terms that are defined in common
the ratio of the ion beam intensity of the major isotope, M,
dictionaries would not also be defined in this terminology
to the background current at the adjacent mass positions.
standard unless there is a need to emphasize a specific
definition in making appropriate use of a Committee C26 ion current at mass M
Abundance sensitivity 5 (1)
ion current at M61
standard.
1.4 Subcommittee C26.10 (Nondestructive Assay) also has
accelerated test, n—for the prediction of long term behavior of
a terminology standard applicable to its standards: Terminol-
materials, a test that results in an increase either in the rate
ogy C1673.
of an alteration mode or in the extent of reaction progress,
when compared with expected service conditions.
1.5 This international standard was developed in accor-
DISCUSSION—Changes in the expected alteration mechanism(s)
dance with internationally recognized principles on standard-
caused by the accelerated test conditions, if any, must be accounted for
ization established in the Decision on Principles for the
in the use of the accelerated test data.
Development of International Standards, Guides and Recom-
accuracy, n—the closeness of agreement between a measure-
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee. ment result and an accepted reference. (E170)
–1
activity, A, [T ], n—the measure of the rate of spontaneous
nuclear transformations of a radioactive material. The SI unit
This terminology is under the jurisdiction of ASTM Committee C26 on Nuclear
Fuel Cycle and is the direct responsibility of Subcommittee C26.01 on Editorial and
Terminology. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Jan. 1, 2024. Published March 2024. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1977. Last previous edition approved in 2023 as C859 – 23. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/C0859-24. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C859 − 24
for activity is the becquerel (Bq), defined as one transfor- annealing, n—in glass leach tests, a controlled cooling process
mation per second. The original unit for activity was the for glass designed to reduce thermal residual stress to an
curie (Ci), defined as 3.7 × 10 transformations per second. acceptable level, and, in some cases, modify structure.
artificial aging, n—any short time treatment that is designed to
alpha radiation, n—is the spontaneous emission of an alpha
particle, composed of two protons and two neutrons with a duplicate or simulate the material/property changes that
positive charge of plus two, during the nuclear transforma- normally occur after prolonged exposure and radioactive
decay.
tion process.
DISCUSSION—An alpha particle is the same as a helium-4 atom with
attribute test, n—for the prediction of long-term behavior of
no electrons.
materials, a test conducted to provide material property data
alteration, n—any change in the form, state, or properties of
that are required as input to behavior models, but are not
materials.
themselves responses to the environment, such as density,
thermal conductivity, mechanical properties, radionuclide
alteration layer, n—in materials interaction with water, a
content of waste forms, and so forth.
layer of alteration phases at the surface of the specimen.
DISCUSSION—Several distinct layers may form at the surface and
back-reaction, n—reaction between dissolved components
within cracks in the material. Layers may be composed of discrete
and a material to re-form bonds that are broken during
crystallites.
dissolution of this material.
alteration mechanism, n—the series of fundamental chemical –1
becquerel (Bq), [T ], n—the SI unit of measure for activity,
or physical processes by which alteration occurs.
defined as one transformation per second.
alteration mode, n—for the prediction of long-term behavior
beta radiation, n—an electron that was generated in the
of materials, a particular form of alteration, for example:
atomic nucleus during decay and has a negative charge of
general corrosion, localized corrosion.
one.
alteration phase, n—in materials interactions with their
bias of a measurement process, n—a consistent or systematic
environment, a solid phase formed as a result of material
difference between a set of test results obtained from the
interactions, that replaces some amount of the original
process when measuring a property, and the accepted refer-
phase; may form by precipitation from solution of in-situ
ence value of the property being measured.
transformation of a chemically altered solid.
bounding model, n—for the prediction of long term behavior
alteration product, n—see alteration phase.
of materials, a model that yields values for dependent
variables or effects that are expected to be either always
aluminum-based spent nuclear fuel, n—irradiated nuclear
greater than or always less than those expected for the
fuel or target elements or assemblies, or both, that are clad in
variables or effects to be bounded.
aluminum or aluminum-rich alloys.
DISCUSSION—The microstructures contain a continuous aluminum-
calcine, v—to fire or heat a granular or particulate solid at less
rich matrix with fissile-rich particles dispersed in this matrix.
than fusion temperature but sufficiently to remove most of its
chemically combined volatile matter (for example, H O,
aluminum-based spent nuclear fuel form or waste form,
CO ) and otherwise to develop the desired properties for use.
n—any metallic form produced from aluminum-based spent 2
nuclear fuel and having a microstructure containing a
calibration, n—the set of operations that establishes, under
continuous aluminum-rich matrix with uranium-rich par-
specified conditions, a relationship between a set of values
ticles dispersed in this matrix.
measured or indicated by an instrument or system to a
DISCUSSION—This term may include the fuel itself or the product
corresponding set of known values, typically derived from
from the melt-dilute process.
appropriate reference standards or established physical con-
stants.
analog, n—for the prediction of long term behavior of
DISCUSSION—The calibration relationship can be expressed by a
materials, a material, process, or system whose composition,
statement, function, diagram or table.
and environmental history are sufficiently similar to those
anticipated for the materials, processes, or systems of
DISCUSSION—Test Method C1108 is an example of calibration using
interest to permit use of insight gained regarding its condi- established physical constants.
tion or behavior to be applied to the material, process, or
DISCUSSION—Additional details on calibration requirements for mea-
system of interest.
surement methods used for the nuclear fuel cycle can be found in Guide
C1156.
analysis (physical or chemical), n—the determination of
physical or chemical properties or composition of a material. DISCUSSION—Some applications or test methods will require the
performance of metrologically traceable calibrations.
analyte, n—in method of chemical analysis, a sample compo-
canyon, n—in the nuclear industry, a long, narrow, remotely
nent whose presence and concentration is of interest.
operated, radiological facility.
analytical sample, n—a portion of a material (solid, liquid, or
DISCUSSION—A large, heavily-shielded facility where nuclear mate-
gas) used in chemical, physical, or radiological analysis. rial is processed or stored.
C859 − 24
DISCUSSION—Compositions reflect materials exposed to coolant and
chemical durability, n—in leach tests, the resistance of a
activation products formed during irradiation.
material to alteration, dissolution, and release of its
constituents, under the specific conditions of the test.
crushed glass, n—in a glass leach test, small particles of glass
produced by mechanically fracturing larger pieces of glass.
chemisorbed water, n—in the drying of spent nuclear fuel,
water that is bound to other species by forces whose energy
cumulative fraction leached, n—in leach tests, the sum of the
levels approximate those of chemical bounds.
amounts of a species leached during all leaching intervals
divided by the amount of that species originally present in
closed system, n—in leach tests, a system utilizing a test
the sample.
container that is impervious to material transport.
–1
curie (Ci), [T ], n—the original unit of measure for activity,
confinement, n—in a dry cask storage system (DCSS) for
defined as 3.7 × 10 transformations per second.
spent nuclear fuel in the U.S., the ability of a DCSS to
prevent the release of radioactive substances into the envi- debris waste, n—in nuclear waste management in the U.S.,
solid material exceeding a 60 mm particle size that is
ronment.
intended for disposal.
confinement systems, n—in a dry cask storage system (DCSS)
DISCUSSION—Additionally, the solid material is a manufactured
for spent nuclear fuel in the U.S., the assembly of compo-
object, or plant, or animal matter, or natural geologic material.
nents of the packaging intended to retain the radioactive
destructive analysis (DA), n—measurement of one or more
material during storage.
attributes of a test specimen in which the chemical or
DISCUSSION—These may include the cladding, storage system shell,
physical properties, or both, of the test specimen are altered
bottom and lid, penetration covers, the closure welds or seals, and bolts
and other components. either during sample preparation or as a result of the
measurement, or both.
confirmation test, n—for the prediction of long term behavior
of materials, a test for which results are not used in the initial determination, n—the process of carrying out a series of
development of a model or the determination of parameter operations specified in the test method whereby a single
values for a model but are used for comparison with value is obtained.
predictions of that model for model validation.
devitrified glass, n—an initially homogenous or phase sepa-
rated glass, or both, that has partially crystallized during
continuing calibration blank check solution (CCB)—in
cooling, heat treatment, or both.
methods of chemical analysis, a standard solution that has no
analyte and is used to verify blank response and freedom 2 1
diffusion coefficient, D, [L T ], n—in diffusion modeling, an
from carryover.
intrinsic property of a species in a host matrix that relates (1)
its concentration gradient to its flux (Fick’s first law), (2) its
continuing calibration verification check solution
spatial rate of change in the direction of the concentration
(CCV)—in methods of chemical analysis, a standard solu-
gradient to the time rate of change in its concentration
tion (or set of solutions) used to verify freedom from
(Fick’s second law), or (3) its mean square displacement to
excessive instrument drift; the concentration is to be near the
time (The Einstein’s equation).
midrange of a linear curve.
disposal, n—in high-level radioactive waste management, the
continuous flow, n—for leach tests, the continual replacement
emplacement in a geologic repository of high-level radioac-
of solution in the reaction cell with fresh test solution.
tive waste, spent nuclear fuel, or other highly radioactive
control test, n—for leach tests, test conducted without a
material with no foreseeable intent of recovery, whether or
specimen to measure background concentrations in the
not such emplacement permits the recovery of such waste.
leachant and contamination from interactions between test
dissolution, n—for leach tests on solids, the result of reactions
solution and apparatus.
in which chemical bonds are broken and species are released
corrosion product, n—for aluminum-based spent fuel storage
from a solid material and become solvated in the test
or disposal, an ion or compound formed during the interac-
solution.
tion of the aluminum-based spent nuclear fuel with its
2 -2
dose equivalent, [L T ], n—a measure of the biological
storage or disposal environment.
effects of radiation dose from all types of radiation expressed
DISCUSSION—The corrosion product may be the result of aqueous
on a common scale.
corrosion, oxidation, reaction with moist air, or other types of chemical
DISCUSSION—The SI unit for dose equivalent is the sievert (Sv),
or electrochemical interactions.
which is equal to 100 rem (specialized unit for human dose equivalent).
CRUD, acr—in nuclear waste management, deposits on fuel
Radiation dose equivalent is often expressed in terms of microsieverts
surfaces of corrosion products that circulate in the reactor (μSv) or millirem (mrem).
coolant.
2 –3
dose rate, [L T ], n—a quantity of absorbed dose received in
a given unit of time.
dry cask storage system (DCSS), n—in nuclear waste
Raddatz, M. G., Waters, M. D., “Information Handbook on Independent Spent
management, a set of components that performs the func-
Fuel Storage Installations,” U.S. Nuclear Regulatory Commission, Office of Nuclear
Materials Safety and Safeguards, NUREG-1571, December 1996. tions of confinement, radiological shielding, and physical
C859 − 24
...

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: C859 − 23 C859 − 24
Standard Terminology Relating to
Nuclear Materials
This standard is issued under the fixed designation C859; 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
1.1 This terminology standard containscovers terms, definitions, descriptions of terms, nomenclature, and explanations of
acronyms and symbols specifically associated with standards under the jurisdiction of Committee C26 on Nuclear Fuel Cycle. The
content of this terminology standard may also be applicable to documents not under the jurisdiction of Committee C26, in which
case this terminology standard may be referenced in those documents.
1.2 While subcommittees within Committee C26 are free to only provide terms and definitions within individual standards, each
subcommittee may request the addition of utilized terms and definitions to this terminology standard if it believes that such serves
the broader interest of Committee C26 and the nuclear fuel cycle profession. Therefore, terms and definitions proposed for
inclusion in Terminology C859 need not be used in more than one committee standard before being considered.
1.3 In general, technical terms that are defined in common dictionaries would not also be defined in this terminology standard
unless there is a need to emphasize a specific definition in making appropriate use of a Committee C26 standard.
1.4 Subcommittee C26.10 (Nondestructive Assay) also has a terminology standard applicable to its standards: Terminology
C1673.
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.
2. Referenced Documents
2.1 ASTM Standards:
C1108 Test Method for Plutonium by Controlled-Potential Coulometry
C1156 Guide for Establishing Calibration for a Measurement Method Used to Analyze Nuclear Fuel Cycle Materials
C1673 Terminology of C26.10 Nondestructive Assay Methods
3. Terminology
3.1 Definitions:
2 -2
absorbed dose, D, [L T ], n—absorbed dose is the mean energy imparted by ionizing radiation to a unit mass of specified
material.
This terminology is under the jurisdiction of ASTM Committee C26 on Nuclear Fuel Cycle and is the direct responsibility of Subcommittee C26.01 on Editorial and
Terminology.
Current edition approved Feb. 15, 2023Jan. 1, 2024. Published March 2023March 2024. Originally approved in 1977. Last previous edition approved in 20222023 as
C859 – 22C859 – 23.A. DOI: 10.1520/C0859-23.10.1520/C0859-24.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C859 − 24
DISCUSSION—
The SI unit for absorbed dose is the gray (Gy), defined as 1 J/kg.
abundance sensitivity, n—in methods of chemical analysis, the ratio of the ion beam intensity of the major isotope, M, to the
background current at the adjacent mass positions.
ion current at mass M
Abundance sensitivity 5 (1)
ion current at M61
accelerated test, n—for the prediction of long term behavior of materials, a test that results in an increase either in the rate of
an alteration mode or in the extent of reaction progress, when compared with expected service conditions.
DISCUSSION—
Changes in the expected alteration mechanism (s) mechanism(s) caused by the accelerated test conditions, if any, must be accounted for in the use of
the accelerated test data.
accuracy, n—the closeness of agreement between a measurement result and an accepted reference. (E170)
–1
activity, A, [T ], n—the measure of the rate of spontaneous nuclear transformations of a radioactive material. The SI unit for
activity is the becquerel (Bq), defined as one transformation per second. The original unit for activity was the curie (Ci), defined
as 3.7 × 10 transformations per second.
alpha radiation, n—is the spontaneous emission of an alpha particle, composed of two protons and two neutrons with a positive
charge of plus two, during the nuclear transformation process.
DISCUSSION—
An alpha particle is the same as a helium-4 atom with no electrons.
alteration, n—any change in the form, state, or properties of materials.
alteration layer, n—in materials interaction with water, a layer of alteration phases at the surface of the specimen.
DISCUSSION—
Several distinct layers may form at the surface and within cracks in the material. Layers may be composed of discrete crystallites.
alteration mechanism, n—the series of fundamental chemical or physical processes by which alteration occurs.
alteration mode, n—for the prediction of long-term behavior of materials, a particular form of alteration, for example: general
corrosion, localized corrosion.
alteration phase, n—in materials interactions with their environment, a solid phase formed as a result of material interactions,
that replaces some amount of the original phase; may form by precipitation from solution of in-situ transformation of a
chemically altered solid.
alteration product, n—see alteration phase.
aluminum-based spent nuclear fuel, n—irradiated nuclear fuel or target elements or assemblies, or both, that are clad in
aluminum or aluminum-rich alloys.
DISCUSSION—
The microstructures contain a continuous aluminum-rich matrix with fissile-rich particles dispersed in this matrix.
aluminum-based spent nuclear fuel form or waste form, n—any metallic form produced from aluminum-based spent nuclear
fuel and having a microstructure containing a continuous aluminum-rich matrix with uranium-rich particles dispersed in this
matrix.
DISCUSSION—
This term may include the fuel itself or the product from the melt-dilute process.
C859 − 24
analog, n—for the prediction of long term behavior of materials, a material, process, or system whose composition, and
environmental history are sufficiently similar to those anticipated for the materials, processes, or systems of interest to permit
use of insight gained regarding its condition or behavior to be applied to the material, process, or system of interest.
analysis (physical or chemical), n—the determination of physical or chemical properties or composition of a material.
analyte, n—in method of chemical analysis, a sample component whose presence and concentration is of interest.
analytical sample, n—a portion of a material (solid, liquid, or gas) used in chemical, physical, or radiological analysis.
annealing, n—in glass leach tests, a controlled cooling process for glass designed to reduce thermal residual stress to an
acceptable level, and, in some cases, modify structure.
artificial aging, n—any short time treatment that is designed to duplicate or simulate the material/property changes that normally
occur after prolonged exposure and radioactive decay.
attribute test, n—for the prediction of long-term behavior of materials, a test conducted to provide material property data that
are required as input to behavior models, but are not themselves responses to the environment, such as density, thermal
conductivity, mechanical properties, radionuclide content of waste forms, and so forth.
back-reaction, n—reaction between dissolved components and a material to re-form bonds that are broken during dissolution
of this material.
–1
becquerel (Bq), [T ], n—the SI unit of measure for activity, defined as one transformation per second.
beta radiation, n—an electron that was generated in the atomic nucleus during decay and has a negative charge of one.
bias of a measurement process, n—a consistent or systematic difference between a set of test results obtained from the process
when measuring a property, and the accepted reference value of the property being measured.
bounding model, n—for the prediction of long term behavior of materials, a model that yields values for dependent variables
or effects that are expected to be either always greater than or always less than those expected for the variables or effects to be
bounded.
calcine, v—to fire or heat a granular or particulate solid at less than fusion temperature but sufficiently to remove most of its
chemically combined volatile matter (for example, H O, CO ) and otherwise to develop the desired properties for use.
2 2
calibration, n—the set of operations that establishes, under specified conditions, a relationship between a set of values measured
or indicated by an instrument or system to a corresponding set of known values, typically derived from appropriate reference
standards or established physical constants.
DISCUSSION—
The calibration relationship can be expressed by a statement, function, diagram or table.
DISCUSSION—
Test Method C1108 is an example of calibration using established physical constants.
DISCUSSION—
Additional details on calibration requirements for measurement methods used for the nuclear fuel cycle can be found in Guide C1156.
DISCUSSION—
Some applications or test methods will require the performance of metrologically traceable calibrations.
C859 − 24
canyon, n—in the nuclear industry, a long, narrow, remotely operated, radiological facility.
DISCUSSION—
A large, heavily-shielded facility where nuclear material is processed or stored.
chemical durability, n—in leach tests, the resistance of a material to alteration, dissolution, and release of its constituents, under
the specific conditions of the test.
chemisorbed water, n—in the drying of spent nuclear fuel, water that is bound to other species by forces whose energy levels
approximate those of chemical bounds.
closed system, n—in leach tests, a system utilizing a test container that is impervious to material transport.
confinement, n—in a dry cask storage system (DCSS) for spent nuclear fuel in the U.S., the ability of a DCSS to prevent the
release of radioactive substances into the environment.
confinement systems, n—in a dry cask storage system (DCSS) for spent nuclear fuel in the U.S., the assembly of components
of the packaging intended to retain the radioactive material during storage.
DISCUSSION—
These may include the cladding, storage system shell, bottom and lid, penetration covers, the closure welds or seals, and bolts and other components.
confirmation test, n—for the prediction of long term behavior of materials, a test for which results are not used in the initial
development of a model or the determination of parameter values for a model but are used for comparison with predictions of
that model for model validation.
continuing calibration blank check solution (CCB)—in methods of chemical analysis, a standard solution that has no analyte
and is used to verify blank response and freedom from carryover.
continuing calibration verification check solution (CCV)—in methods of chemical analysis, a standard solution (or set of
solutions) used to verify freedom from excessive instrument drift; the concentration is to be near the midrange of a linear curve.
continuous flow, n—for leach tests, the continual replacement of solution in the reaction cell with fresh test solution.
control test, n—for leach tests, test conducted without a specimen to measure background concentrations in the leachant and
contamination from interactions between test solution and apparatus.
corrosion product, n—for aluminum-based spent fuel storage or disposal, an ion or compound formed during the interaction
of the aluminum-based spent nuclear fuel with its storage or disposal environment.
DISCUSSION—
The corrosion product may be the result of aqueous corrosion, oxidation, reaction with moist air, or other types of chemical or electrochemical
interactions.
CRUD, acr—in nuclear waste management, deposits on fuel surfaces of corrosion products that circulate in the reactor coolant.
DISCUSSION—
Compositions reflect materials exposed to coolant and activation products formed during irradiation.
crushed glass, n—in a glass leach test, small particles of glass produced by mechanically fracturing larger pieces of glass.
Raddatz, M. G., Waters, M. D., “Information Handbook on Independent Spent Fuel Storage Installations,” U.S. Nuclear Regulatory Commission, Office of Nuclear
Materials Safety and Safeguards, NUREG-1571, December 1996.
C859 − 24
cumulative fraction leached, n—in leach tests, the sum of the amounts of a species leached during all leaching intervals divided
by the amount of that species originally present in the sample.
–1 10
curie (Ci), [T ]—], n—the original unit of measure for activity, defined as 3.7 × 10 transformations per second.
debris waste, n—in nuclear waste management in the U.S., solid material exceeding a 60 mm particle size that is intended for
disposal.
DISCUSSION—
Additionally, the solid material is a manufactured object, or plant, or animal matter, or natural geologic material.
destructive analysis (DA), n—measurement of one or more attributes of a test specimen in which the chemical or physical
properties, or both, of the test specimen are altered either during sample preparation or as a result of the measurement, or both.
determination, n—the process of carrying out a series of operations specified in the test method whereby a single value is
obtained.
devitrified glass, n—an initially homogenous or phase separated glass, or both, that has partially crystallized during cooling,
heat treatment, or both.
2 1
diffusion coefficient, D, [L T ], n—in diffusion modeling, an intrinsic property of a species in a host matrix that relates (1) its
concentration gradient to its flux (Fick’s first law), (2) its spatial rate of change in the direction of the concentration gradient to
the time rate of change in its concentration (Fick’s second law), or (3) its mean square displacement to time (The Einstein’s
equation).
disposal, n—in high-level radioactive waste management, the emplacement in a geologic repository of high-level radioactive
waste, spent nuclear fuel, or other highly radioactive material with no foreseeable intent of recovery, whether or not such
emplacement permits the recovery of such waste.
dissolution, n—for leach tests on solids, the result of reactions in which chemical bonds are broken and species are released from
a solid material and become solvated in the test solution.
2 -2
dose equivalent, [L T ], n—a measure of the biological effects of radiation dose from all types of radiation expressed on a
common scale.
DISCUSSION—
The SI unit for dose equivalent is the sievert (Sv), which is equal to 100 rem (specialized unit for human dose equivalent). Radiation dose equivalent
is often expressed in terms of microsieverts (μSv) or millirem (mrem).
2 –3
dose rate, [L T ], n—a quantity of absorbed dose received in a given unit of time.
dry cask storage system (DCSS), n—in nuclear waste management, a set of components that performs the functions of
confinement, radiological
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