ASTM C1831/C1831M-17(2022)

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: C1831/C1831M − 17 (Reapproved 2022)
Standard Guide for
Gamma Radiation Shielding Performance Testing
This standard is issued under the fixed designation C1831/C1831M; 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 1.7 This guide is not applicable to neutron radiation shield-
ing performance evaluations.
1.1 This guide identifies appropriate test methods for deter-
mining the sufficiency of radiological shielding for hot cells 1.8 Units—The values stated in either SI units or inch-
and shielded enclosures. pound units are to be regarded separately as standard. The
values stated in each system may not be exact equivalents;
1.2 After constructing or modifying radiological shielding,
therefore,eachsystemshallbeusedindependentlyoftheother.
it is necessary to verify that shielding performance meets or
Combining values from the two systems may result in noncon-
exceeds the shielding performance requirements. This is typi-
formance with the standard.
cally accomplished using sealed test sources of much less
1.8.1 Units for total activity should be given in Becquerel
activity than the design basis. This allows for modifications or
(Bq) or curies (Ci).
correction of any discrepancies identified before the commis-
1.8.2 Units for dose rate as measured during testing should
sioning of the hot cell.
be given in Sieverts (Sv/h) or rad/h.
1.3 The guidance and practices recommended by this guide
1.8.3 Distances and locations should be provided in centi-
are applicable to both new and existing shielded facilities and
metres or inches.
enclosures for evaluating shielding suitability and locating the
1.9 This standard does not purport to address all of the
existenceofshinepathsorothershieldinganomaliesthatresult
safety concerns, if any, associated with its use. It is the
from design, manufacture, or construction.
responsibility of the user of this standard to establish appro-
1.4 Two types of testing may be performed.
priate safety, health, and environmental practices and deter-
1.4.1 Shielding performance verification testing provides
mine the applicability of regulatory limitations prior to use.
evidence that the shielding configuration is sufficient for
1.10 This international standard was developed in accor-
meeting established performance criteria and for identifying
dance with internationally recognized principles on standard-
deficiencies in the shielding configuration or components that
ization established in the Decision on Principles for the
may not have been addressed during design. Test results are
Development of International Standards, Guides and Recom-
expected to demonstrate that shielding performance meets or
mendations issued by the World Trade Organization Technical
exceeds design criteria, not match the dose rates predicted
Barriers to Trade (TBT) Committee.
analytically.
1.4.2 Shielding performance verification testing identifies
2. Referenced Documents
shielding deficiencies (hot spots) in the installed configuration
2.1 ASTM Standards:
relative to adjacent shielding but does not demonstrate com-
C859 Terminology Relating to Nuclear Materials
pliance with any quantitative shielding performance require-
ment.
3. Terminology
1.5 Performance testing should be specified and performed
3.1 For terms not defined in this guide, see Terminology
to assess shielding adequacy with sources in all critical
C859.
locations.
3.2 Definitions:
1.6 Requirements for shielding performance testing should
3.2.1 angular response sensitivity, n—the ability of an
be clearly defined in design basis or procurement documenta-
instrument or detector to detect radiation based on the angle of
tion.
incidence of the radiation on the instrument or detector.
This guide is under the jurisdiction ofASTM Committee C26 on Nuclear Fuel
Cycle and is the direct responsibility of Subcommittee C26.14 on Remote Systems. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved July 1, 2022. Published July 2022. Originally approved contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
in 2017. Last previous edition approved in 2017 as C1831/C1831M – 17. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/C1831_C1831M-17R22. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1831/C1831M − 17 (2022)
3.2.2 Bremsstrahlung radiation, n—electromagnetic radia- 3.2.11 shielding performance verification testing, n—testing
tion produced by the deceleration of a charged particle when used to demonstrate that shielding meets or exceeds the
deflected by another charged particle, typically an electron by performance requirements established in the design basis or
an atomic nucleus. procurement documents.
3.2.2.1 Discussion—The moving particle loses kinetic
3.2.12 skyshine, n—radiation that is scattered by the atmo-
energy, which is converted into a photon because energy is
sphere or adjacent structures above a radiation source to points
conserved.
on the ground around the outsider perimeter.
3.2.3 buildup factor, n—for radiation passing through a
3.3 Definitions of Terms Specific to This Standard:
medium, the buildup factor is the ratio of the total value of a
3.3.1 biological shielding, v—for purposes of this guide, it
specific radiation quantity (direct and scattered) measured as
is the radiation-absorbing shield used to protect personnel from
absorbed dose at any point within that medium to the contri-
the effects of nuclear particles or radiation.
bution to that quantity from the incident uncollided radiation
3.3.2 source location volume, n—specifies the zone the
reaching that point.
source is expected to occupy within the shielded enclosure.
3.2.3.1 Discussion—The buildup factor increases with in-
creased shielding thickness and is higher for low atomic
4. Summary of Guide
number materials.
4.1 The test source(s) is positioned within the shielded
3.2.4 encapsulated source, n—sealed source strong enough
enclosureandthedoserateismeasuredatestablishedlocations
tomaintainleaktightnessundertheconditionsofuseforwhich
using a calibrated instrument.
the source was designed and also under foreseeable mishaps.
4.2 It is important that test acceptance criteria reflect the test
3.2.4.1 Discussion—It is radioactive material that is perma-
source and not the design basis source term.
nently sealed in a capsule or closely bonded and in a solid
form.
5. Significance and Use
3.2.5 Geiger-Müller counter, GM, n—type of particle detec-
5.1 Shielding performance testing should be performed to
tor that measures ionizing radiation.
verify analytical predictions of shielding effectiveness, com-
3.2.5.1 Discussion—The radiation-sensing element is an
pliance with design requirements, and determine the loca-
inert gas-filled Geiger-Müller tube (usually containing helium,
tion(s) of shielding deficiencies that may require either supple-
neon, or argon with halogens added) at a low pressure that
mental shielding, design modification, or changes to operating
briefly conducts an electrical charge when a particle or photon
methods and procedures to resolve.
of radiation makes the gas conductive by ionization. GMs
display the number of ionization events, typically in “counts-
5.2 Dose rates higher than adjacent shielding may be
per-second.” The GM tube can detect the presence of radiation
expected in the vicinity of master-slave manipulator penetra-
but not its energy, which determines the ionizing effect.
tions as a result of cable or tape clearance requirements within
Instruments that make use of an energy compensated GM tube
the mechanisms where they pass through the shield walls. This
are capable of displaying absorbed dose.
is true even with supplemental shielding installed in the
3.2.6 ionization chamber, n—beta-gamma radiation meter manipulator through tube.
useful for direct measurement of exposure and dose rates,
5.3 Similar to manipulator penetrations, when sources are
determining shielding effectiveness, checking source
placed directly in front of penetrations and gaps resulting from
containers, monitoring radiation areas, and checking results
access doors or panels, radiation levels directly on the other
following decontamination procedures.
side of the gaps or penetrations may be higher than levels in
3.2.6.1 Discussion—The unit contains an ion chamber that
adjacent shielding or analytical predictions. If these test con-
converts directly from ion chamber current to dose rate.
figurations are representative of how the shielded enclosure
will actually be operated (that is, the test configuration is
3.2.7 manipulator through tube, n—penetration provided
representative of engineered source and normally occupied
specifically for installation of a master-slave manipulator.
work locations) than the additional expense of designing or
3.2.7.1 Discussion—Typically, a hole with a diameter of a
modifying the shielded enclosure should be considered if that
certain size depending on the manipulator being used that
location is normally occupied and will result in a significant
passes horizontally though the shi
...