ASTM C1308-21

Standard Test Method for Accelerated Leach Test for Measuring Contaminant Releases From Solidified Waste

SIGNIFICANCE AND USE
5.1 This test method can be used to measure the release of a component from a solidified waste form into water at the reference temperature near 20 °C and at elevated temperatures that accelerate the rate and extent of leaching relative to the values measured at the reference temperature. Results of this test method can be used to quantify an intrinsic property of a material, but should not be presumed to represent releases in specific disposal environments. Tests can be conducted under conditions that represent a specific disposal environment (for example, by using a representative groundwater) to determine effective parameter values for those conditions.  
5.2 This test method can be used to:  
5.2.1 Compare releases of waste components from various types of solidification agents and formulations.  
5.2.2 Determine the model parameter values quantifying the release of contaminants from a waste or waste form at a specific temperature.  
5.2.3 Promote greater extents of reaction than can be achieved under expected service conditions within a laboratory time frame to provide greater confidence in modeled contaminant releases.  
5.2.4 Determine the temperature dependence of contaminant release.  
5.3 Fitting the experimental results with a mechanistic model allows release behaviors to be extrapolated to long times and to full-scale waste forms under the following constraints:  
5.3.1 The same model must be used to represent the results of tests conducted at elevated temperatures and at the reference temperature because the mechanism must be the same.  
5.3.2 Projections of releases over long times require that the waste form matrix remain stable, which may be demonstrated by the physical robustness of specimens recovered from tests conducted at elevated temperatures.  
5.3.3 Extrapolations in time at any temperature within the range tested are limited to values that correspond to the maximum CFL value that was measured.
SCOPE
1.1 This test method provides a procedure for measuring the release rates of elements from a solidified matrix material under conditions that mitigate solution feedback effects. Results can be analyzed by using different models to determine if the elemental releases are controlled by mass transport though the matrix (that is, by diffusion), by a surface dissolution process, or by a combination of processes. This test method is applicable to any material that does not deform during the test.  
1.1.1 If mass diffusion is the dominant process in the release mechanism, then the results of this test can be used to derive diffusion coefficients for use in diffusion-based mathematical models.  
1.1.2 If surface dissolution is the dominant process, then the results of this test can be used to derive the kinetic dissolution rate in the absence of reaction affinity effects for use in dissolution-based mathematical models.  
1.1.3 If release is controlled by coupled or combined dissolution and mass transport processes, then the results of this test can be used to derive effective coefficient values for a mechanistic or empirical model.  
1.2 Tests at elevated temperatures are used to accelerate the release process to determine the temperature range over which the release mechanism does not change and to generate results that can be used for calculating releases at lower temperatures over long times, provided that the release mechanism does not change with temperature.  
1.2.1 Tests conducted at high temperatures can be used to determine the temperature dependence of model coefficients.  
1.2.2 The mechanism is considered to remain unchanged over a range of temperatures if the model coefficients show Arrhenius behavior over that range.  
1.2.3 Releases at any temperature within that range can be projected in time up to the highest cumulative fractional release value that has been measured for that material.  
1.3 The values stated in SI units are to be regarded as s...

General Information

• Status: Published
• Publication Date: 31-Jan-2021
• ICS: 13.030.10 - Solid wastes
• Technical Committee: C26 - Nuclear Fuel Cycle
• Drafting Committee: C26.13 - Spent Fuel and High Level Waste

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:C1308 −21
Standard Test Method for
Accelerated Leach Test for Measuring Contaminant
1
Releases From Solidified Waste
This standard is issued under the fixed designation C1308; 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 1.3 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
1.1 Thistestmethodprovidesaprocedureformeasuringthe
standard.
release rates of elements from a solidified matrix material
under conditions that mitigate solution feedback effects. Re-
1.4 This standard does not purport to address all of the
sults can be analyzed by using different models to determine if safety concerns, if any, associated with its use. It is the
the elemental releases are controlled by mass transport though
responsibility of the user of this standard to establish appro-
the matrix (that is, by diffusion), by a surface dissolution priate safety, health, and environmental practices and deter-
process, or by a combination of processes. This test method is
mine the applicability of regulatory limitations prior to use.
applicable to any material that does not deform during the test.
1.5 This international standard was developed in accor-
1.1.1 Ifmassdiffusionisthedominantprocessintherelease
dance with internationally recognized principles on standard-
mechanism, then the results of this test can be used to derive
ization established in the Decision on Principles for the
diffusion coefficients for use in diffusion-based mathematical
Development of International Standards, Guides and Recom-
models.
mendations issued by the World Trade Organization Technical
1.1.2 Ifsurfacedissolutionisthedominantprocess,thenthe
Barriers to Trade (TBT) Committee.
results of this test can be used to derive the kinetic dissolution
rate in the absence of reaction affinity effects for use in
2. Referenced Documents
dissolution-based mathematical models.
2
2.1 ASTM Standards:
1.1.3 If release is controlled by coupled or combined
C1220TestMethodforStaticLeachingofMonolithicWaste
dissolution and mass transport processes, then the results of
Forms for Disposal of Radioactive Waste
this test can be used to derive effective coefficient values for a
mechanistic or empirical model.
3. Terminology
1.2 Tests at elevated temperatures are used to accelerate the
3.1 Definitions:
release process to determine the temperature range over which
3.1.1 cumulative fraction leached—the sum of the fractions
the release mechanism does not change and to generate results
of a species leached during all sampling intervals prior to and
that can be used for calculating releases at lower temperatures
including the present interval divided by the amount of that
over long times, provided that the release mechanism does not
species present in the test specimen before the test.
change with temperature.
1.2.1 Tests conducted at high temperatures can be used to
3.1.2 diffusion coeffıcient (diffusivity)—an intrinsic property
determine the temperature dependence of model coefficients.
ofaspeciesthatrelates (1)itsconcentrationgradienttoitsflux
1.2.2 The mechanism is considered to remain unchanged
in a given medium (Fick’s first law), (2) its spatial rate of
over a range of temperatures if the model coefficients show
changeinthedirectionoftheconcentrationgradienttothetime
Arrhenius behavior over that range.
rate of change in its concentration in a given medium (Fick’s
1.2.3 Releases at any temperature within that range can be
second law), or (3) its mean square displacement to time in a
projectedintimeuptothehighestcumulativefractionalrelease
given medium (the Einstein equation).
value that has been measured for that material.
3.1.3 dissolution—the transfer of species from the solid test
specimen into solution.
1
ThistestmethodisunderthejurisdictionofASTMCommitteeC26onNuclear
Fuel Cycle and is the direct responsibility of Subcommittee C26.13 on Spent Fuel
2
and High Level Waste. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Feb. 1, 2021. Published April 2021. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1995. Last previous edition approved in 2017 as C1308–08 (2017). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/C1308-21. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box
...

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: C1308 − 08 (Reapproved 2017) C1308 − 21
Standard Test Method for
Accelerated Leach Test for Diffusive Measuring
Contaminant Releases from Solidified Waste and a
Computer Program to Model Diffusive, Fractional Leaching
1
from Cylindrical Waste FormsFrom Solidified Waste
This standard is issued under the fixed designation C1308; 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 test method provides procedures a procedure for measuring the leachrelease rates of elements from a solidified matrix
material, determining if the material under conditions that mitigate solution feedback effects. Results can be analyzed by using
different models to determine if the elemental releases are controlled by mass diffusion, computing values of diffusion constants
based on models, and verifying projected long-term diffusive releases. transport though the matrix (that is, by diffusion), by a
surface dissolution process, or by a combination of processes. This test method is applicable to any material that does not degrade
or deform during the test.
1.1.1 If mass diffusion is the dominant stepprocess in the leachingrelease mechanism, then the results of this test can be used to
calculate diffusion coefficients using mathematical diffusion models. A computer program developed for that purpose is available
as a companion to this test method (derive diffusion coefficients for use in diffusion-based mathematical models. Note 1).
1.1.2 If surface dissolution is the dominant process, then the results of this test can be used to derive the kinetic dissolution rate
in the absence of reaction affinity effects for use in dissolution-based mathematical models.
1.1.3 It should be verified that leaching If release is controlled by diffusion by a means other than analysis of the leach test solution
data. Analysis of concentration profiles of species of interest near the surface of the solid waste form after the test is recommended
for this purpose.coupled or combined dissolution and mass transport processes, then the results of this test can be used to derive
effective coefficient values for a mechanistic or empirical model.
1.1.3 Potential effects of partitioning on the test results can be identified through modeling, although further testing and analyses
are required to determine the cause of partitioning (for example, if it occurs during production of the material or as a result of
leaching).
1.2 The method is a modification of other semi-dynamic tests such as the IAEA test Tests at (1) and the ANS 16.1 Leach Test
wherein elevated temperatures are used to accelerate diffusivethe release to an extent that would only be reached after very long
times at lower temperatures. This approach provides a mechanistic basis for calculating diffusive releases at repository-
relevantprocess to determine the temperature range over which the release mechanism does not change and to generate results that
can be used for calculating releases at lower temperatures over long times, provided that the leachingrelease mechanism does not
change with temperature.
1
This test method is under the jurisdiction of ASTM Committee C26 on Nuclear Fuel Cycle and is the direct responsibility of Subcommittee C26.13 on Spent Fuel and
High Level Waste.
Current edition approved Jan. 1, 2017Feb. 1, 2021. Published January 2017April 2021. Originally approved in 1995. Last previous edition approved in 20082017 as
C1308 – 08.C1308 – 08 (2017). DOI: 10.1520/C1308-08R17.10.1520/C1308-21.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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C1308 − 21
1.2.1 Tests can be conducted at elevated temperatures to accelerate diffusive release and provide a mechanistic basis for
calculating diffusive releases that would occur at lower temperatures over long times. Tests conducted at high temperatures allow
high temperatures can be used to determine the temperature dependence of the diffusion coefficient to be determined. They also
demonstrate that the diffusion mechanism is rate-limiting through the measured extent of diffusive release. model coefficients.
1.2.2 Releases at any temperature can be projected up to the highest cumulative fractional release value that ha
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