ASTM D8377-21
(Guide)Standard Guide for High Temperature Strength Measurements of Graphite Impregnated with Molten Salt
Standard Guide for High Temperature Strength Measurements of Graphite Impregnated with Molten Salt
SIGNIFICANCE AND USE
4.1 The Molten Salt Reactor is a nuclear reactor which uses graphite as reflector and structural material, and molten salt as coolant. The graphite components will be submerged in the molten salt during the lifetime of the reactor. The porous structure of graphite may lead to molten salt permeation, which can affect the thermal and mechanical properties of graphite. Consequently, it may be necessary to measure the various strengths of the manufactured graphite materials after impregnation with molten salt and before exposure to the reactor environment in a range of test configurations in order for designers or operators to assess their performance.
4.2 For gas-cooled reactors, the strength of a graphite specimen is usually measured at room temperature. However, for molten salt reactors, the operating temperature of the reactor must be higher than the melting temperature of the salt, and so the salt will be in solid state at room temperature. Consequently, room temperature measurements may not be representative of the performance of the material at its true operating conditions. It is therefore necessary to measure the strength at an elevated temperature where the salt is in liquid form. Users should also be aware that a small increase in graphite strength is expected with increasing temperature, and testing at the plant operating temperature will eliminate this small uncertainty.
4.3 The purpose of this guide is to provide considerations, which should be included in testing graphite specimens impregnated with molten salt at elevated temperature.
4.4 For the test results to be meaningful, the test material must have been impregnated at the reactor operating temperature of interest and the strength measurement conducted at the same temperature following the guide here. The user must consider the effect of interaction between graphite and impregnated salt on the representativeness of the strength test based upon the heating and cooling stages between impregnat...
SCOPE
1.1 This guide covers the best practice for strength measurements at elevated temperature of graphite impregnated with molten salt.
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
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
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D8377 − 21
Standard Guide for
High Temperature Strength Measurements of Graphite
1
Impregnated with Molten Salt
This standard is issued under the fixed designation D8377; 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 3. Summary of Guide
1.1 This guide covers the best practice for strength mea- 3.1 There is currently a set of ASTM standards as stated in
surements at elevated temperature of graphite impregnated 2.1 that can be applied to graphite for different strength
with molten salt. measurements (Test Methods C651, C695, C749, D8289).
Each of these standards has been developed specifically to
1.2 The values stated in SI units are to be regarded as
provide a method of measurement for graphite as a single
standard. No other units of measurement are included in this
material. However, in some applications such as in molten salt
standard.
reactors, graphite components are submerged in a molten salt.
1.3 This standard does not purport to address all of the
In order to assess the effect of molten salt on graphite
safety concerns, if any, associated with its use. It is the
components, a method may be necessary for the measurement
responsibility of the user of this standard to establish appro-
of strength for graphite specimens both impregnated with
priate safety, health, and environmental practices and deter-
molten salt and at elevated temperatures (see Section 4). The
mine the applicability of regulatory limitations prior to use.
objective of this guide is to provide advice on the application
1.4 This international standard was developed in accor-
of selected standards for graphite specimens impregnated with
dance with internationally recognized principles on standard-
molten salt and tested at elevated temperatures. This includes
ization established in the Decision on Principles for the
transportation of graphite specimens impregnated with molten
Development of International Standards, Guides and Recom-
salt, temperature measurement, equipment for measuring
mendations issued by the World Trade Organization Technical
compressive, tensile, or flexural strength at elevated
Barriers to Trade (TBT) Committee.
temperature, and safe handling of the molten salt.
2. Referenced Documents
4. Significance and Use
2
2.1 ASTM Standards:
4.1 The Molten Salt Reactor is a nuclear reactor which uses
C651 Test Method for Flexural Strength of Manufactured
graphite as reflector and structural material, and molten salt as
CarbonandGraphiteArticlesUsingFour-PointLoadingat
coolant. The graphite components will be submerged in the
Room Temperature
molten salt during the lifetime of the reactor. The porous
C695 Test Method for Compressive Strength of Carbon and
structureofgraphitemayleadtomoltensaltpermeation,which
Graphite
can affect the thermal and mechanical properties of graphite.
C749 Test Method for Tensile Stress-Strain of Carbon and
Consequently, it may be necessary to measure the various
Graphite
strengths of the manufactured graphite materials after impreg-
D8091 Guide for Impregnation of Graphite with Molten Salt
nation with molten salt and before exposure to the reactor
D8289 Test Method for Tensile Strength Estimate by Disc
environment in a range of test configurations in order for
Compression of Manufactured Graphite
designers or operators to assess their performance.
E4 Practices for Force Verification of Testing Machines
4.2 For gas-cooled reactors, the strength of a graphite
specimen is usually measured at room temperature. However,
for molten salt reactors, the operating temperature of the
1
This guide is under the jurisdiction of ASTM Committee D02 on Petroleum
reactor must be higher than the melting temperature of the salt,
Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcom-
and so the salt will be in solid state at room temperature.
mittee D02.F0 on Manufactured Carbon and Graphite Products.
Consequently, room temperature measurements may not be
Current edition approved Jan. 1, 2021. Published January 2021. DOI: 10.1520/
D8377-21.
representative of the performance of the material at its true
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
operating conditions. It is therefore necessary to measure the
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
strength at an elevated temperature where the salt is in liquid
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. form. Users should also be aware that a small increase in
Copyright © ASTM International, 100 Barr Ha
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.