ISO/ASTM 51702:2013

INTERNATIONAL ISO/ASTM
STANDARD 51702
Third edition
2013-04-15
Practice for dosimetry in a gamma
facility for radiation processing
Practique pour la dosimétrie dans les installations pour
l’irradiation gamma
Reference number
© ISO/ASTM International 2013
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ii © ISO/ASTM International 2013 – All rights reserved

Contents Page
1 Scope . 1
2 Referenced documents . 1
3 Terminology . 1
4 Significance and use . 2
5 Radiation source characteristics . 3
6 Types of facilities . 3
7 Dosimetry system calibration . 3
8 Installation qualification . 3
9 Operational qualification . 4
10 Performance qualification . 5
11 Routine product processing . 7
12 Certification . 7
13 Measurement uncertainty . 8
14 Keywords . 8
Bibliography . 8
© ISO/ASTM International 2013 – All rights reserved iii

Foreword
ISO(theInternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsbodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are circulated to the member bodies for
voting. Publication as an International Standard requires approval by at least 75% of the member bodies
casting a vote.
ASTM International is one of the world’s largest voluntary standards development organizations with global
participation from affected stakeholders. ASTM technical committees follow rigorous due process balloting
procedures.
A pilot project between ISO and ASTM International has been formed to develop and maintain a group of
ISO/ASTM radiation processing dosimetry standards. Under this pilot project, ASTM Committee E61,
Radiation Processing, is responsible for the development and maintenance of these dosimetry standards with
unrestricted participation and input from appropriate ISO member bodies.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. Neither ISO nor ASTM International shall be held responsible for identifying any or all such patent
rights.
International Standard ISO/ASTM 51702 was developed by ASTM Committee E61, Radiation Processing,
through Subcommittee E61.03, Dosimetry Application, and by Technical Committee ISO/TC 85, Nuclear
energy, nuclear technologies and radiological protection.
iv © ISO/ASTM International 2013 – All rights reserved

An American National Standard
Standard Practice for
Dosimetry in a Gamma Facility for Radiation Processing
This standard is issued under the fixed designation ISO/ASTM 51702; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision.
1. Scope E2303 Guide for Absorbed-Dose Mapping in Radiation
Processing Facilities
1.1 This practice outlines the installation qualification pro-
E2628 Practice for Dosimetry in Radiation Processing
gram for an irradiator and the dosimetric procedures to be
E2701 Guide for Performance Characterization of Dosim-
followed during operational qualification, performance quali-
eters and Dosimetry Systems for Use in Radiation Process-
fication, and routine processing in facilities that process prod-
ing
ucts with ionizing radiation from radionuclide gamma sources
2.2 ISO/ASTM Standards:
to ensure that product has been treated within a predetermined
51261 Practice for Calibration of Routine Dosimetry Sys-
rangeofabsorbeddose.Otherproceduresrelatedtooperational
tems for Radiation Processing
qualification, performance qualification, and routine process-
51539 Guide for Use of Radiation-Sensitive Indicators
ing that may influence absorbed dose in the product are also
51608 Practice for Dosimetry in an X-Ray (Bremsstrahl-
discussed.
ung) Facility for Radiation Processing
NOTE 1—Dosimetry is only one component of a total quality assurance
51649 Practice for Dosimetry in an Electron Beam Facility
program for adherence to good manufacturing practices used in radiation
for Radiation Processing at Energies Between 300 KeV
processing applications.
and 25 KeV
NOTE 2—ISO/ASTM Practices 51818 and 51649 describe dosimetric
51707 Guide for Estimating Uncertainties in Dosimetry for
procedures for low and high enery electron beam facilities for radiation
processing and ISO/ASTM Practice 51608 describes procedures for X-ray Radiation Processing
(bremsstrahlung) facilities for radiation processing.
51818 Practice for Dosimetry in an Electron Beam Facility
for Radiation Processing at Energies Between 80 and 300
1.2 For the radiation sterilization of health care products,
keV
see ISO 11137-1. In those areas covered by ISO 11137-1, that
2.3 International Commission on Radiation Units and
standard takes precedence.
Measurements (ICRU) Reports:
1.3 This document is one of a set of standards that provides
ICRU Report 85a Fundamental Quantities and Units for
recommendations for properly implementing and utilizing
Ionizing Radiation
dosimetry in radiation processing. It is intended to be read in
2.4 ISO Standards:
conjunction with ASTM Practice E2628.
ISO 11137-1 Sterilization of health care products – Radia-
1.4 This standard does not purport to address all of the
tion – Part 1: Requirements for development, validation,
safety concerns, if any, associated with its use. It is the
and routine control of a sterilization process for medical
responsibility of the user of this standard to establish appro-
devices
priate safety and health practices and determine the applica-
2.5 Joint Committee for Guides in Metrology (JCGM)
bility of regulatory limitations prior to use.
Reports:
2. Referenced documents
JCGM 100:2008, GUM 1995, with minor corrections,
Evaluation of measurement data – Guide to the Expres-
2.1 ASTM Standards:
sion of Uncertainty in Measurement
E170 TerminologyRelatingtoRadiationMeasurementsand
Dosimetry
3. Terminology
E2232 Guide for Selection and Use of Mathematical Meth-
3.1 Definitions:
odsforCalculatingAbsorbedDoseinRadiationProcessing
3.1.1 absorbed dose, D—quantity of ionizing radiation
Applications
energy imparted per unit mass of a specified material. The SI
unit of absorbed dose is the gray (Gy), where 1 gray is
This practice is under the jurisdiction of ASTM Committee E61 on Radiation
equivalent to the absorption of 1 joule per kilogram of the
Processing and is the direct responsibility of Subcommittee E61.03 on Dosimetry
specified material (1 Gy = 1 J/kg). The mathematical relation-
Application, and is also under the jurisdiction of ISO/TC 85/WG 3.
ship is the quotient of d´¯ by dm, where d´¯ is the mean
Current edition approved Dec. 26, 2012. Published April 2013. Originally
published as E 1702-95. Last previous ASTM edition E 1702–00. ASTM
ϵ1
E 1702–95 was adopted by ISO in 1998 with the intermediate designation ISO
15571:1998(E). The present International Standard ISO/ASTM 51702:2013(E) Available from the International Commission on Radiation Units and Measure-
replaces ISO 15571 and is a major revision of the last previous edition ISO/ASTM ments, 7910 Woodmont Ave., Suite 800, Bethesda, MD 20814, USA.
51702–2004(E). Available from International Organization for Standardization (ISO), 1 rue de
For referenced ASTM and ISO/ASTM standards, visit the ASTM website, Varembé, Case postale 56, CH-1211, Geneva 20, Switzerland, http://www.iso.ch.
www.astm.org, or contact ASTM Customer Service at service@astm.org. For Document produced by Working Group 1 of the Joint Committee for Guides in
Annual Book of ASTM Standards volume information, refer to the standard’s Metrology (JCGM/WG 1). Available free of charge at the BIPM website (http://
Document Summary page on the ASTM website. www.bipm.org).
© ISO/ASTM International 2013 – All rights reserved
incremental energy imparted by ionizing radiation to matter of 3.1.14.1 Discussion—For a shuffle-dwell irradiator the
incremental mass dm (see ICRU Report 85a). timer setting is the time interval from the start of one
shuffle-dwell cycle to the start of the next shuffle-dwell cycle.
D 5 d´¯/dm (1)
For a stationary irradiator, the timer setting is the total
3.1.2 absorbed-dose mapping—measurement of absorbed
irradiation time.
dose within an irradiation product to produce a one-, two- or
3.2 Definitions of other terms used in this standard that
three-dimensionaldistributionofabsorbeddose,thusrendering
pertain to radiation measurement and dosimetry may be found
a map of absorbed-dose values.
in ASTM Terminology E170. Definitions in E170 are compat-
3.1.3 calibration curve—expression of the relation between
ible with ICRU Report 85a; ICRU Report 85a, therefore, may
indication and corresponding measured quantity value.
be used as an alternative reference.
3.1.3.1 Discussion—In radiation processing standards, the
term “dosimeter response” is generally used for “indication.”
4. Significance and use
3.1.4 compensating dummy—See simulated product.
4.1 Various products and materials routinely are irradiated
3.1.5 dosimeter response—reproducible, quantifiable radia-
at predetermined doses in gamma irradiation facilities to
tion effect produced in the dosimeter by ionizing radiation.
reduce their microbial population or to modify their character-
3.1.6 dosimeter set—one or more dosimeters used to mea-
istics. Dosimetry requirements may vary depending upon the
suretheabsorbeddoseatalocationandwhoseaveragereading
irradiation application and end use of the product. Some
is used as the absorbed-dose measurement at that location.
examples of irradiation applications where dosimetry may be
3.1.7 dosimetry system—system used for absorbed dose,
used are:
consisting of dosimeters, measurement instruments and their
4.1.1 Sterilization of medical devices,
associatedreferencestandards,andproceduresforthesystem’s
4.1.2 Treatment of food for the purpose of parasite and
use.
pathogen control, insect disinfestation, and shelf life extension,
3.1.8 installation qualification (IQ)—process of obtaining
4.1.3 Disinfection of consumer products,
and documenting evidence that equipment has been provided
4.1.4 Cross-linking or degradation of polymers and elasto-
and installed in accordance with specifications.
mers,
3.1.9 irradiation container—holder in which product is
4.1.5 Polymerization of monomers and grafting of mono-
placed during the irradiation process.
mers onto polymers,
3.1.9.1 Discussion—“Irradiationcontainer”isoftenreferred
4.1.6 Enhancement of color in gemstones and other mate-
tosimplyas“container”andcanbeacarrier,cart,tray,product
rials,
carton, pallet, product package or other holder.
4.1.7 Modification of characteristics of semiconductor de-
3.1.10 operational qualification (OQ)—process of obtain-
vices, and
ing and documenting evidence that installed equipment oper-
4.1.8 Research on materials effects.
ates within predetermined limits when used in accordance with
its operational procedures.
NOTE 3—Dosimetry is required for regulated irradiation processes such
3.1.11 performance qualification (PQ)—process of obtain- assterilizationofmedicaldevicesandthetreatmentoffood.Itmaybeless
important for other industrial processes, for example, polymer modifica-
ing and documenting evidence that the equipment, as installed
tion, which can be evaluated by changes in the physical and chemical
and operated in accordance with operational procedures, con-
properties of the irradiated materials.
sistently performs in accordance with predetermined criteria
and thereby yields product meeting its specification.
4.2 An irradiation process usually requires a minimum
absorbeddosetoachievetheintendedeffect.Therealsomaybe
3.1.12 production run (for continuous-flow and shuffle-
dwell irradiations)—series of irradiation containers consisting a maximum absorbed dose that the product can tolerate and
of materials or products having similar radiation-absorption still meet its functional or regulatory specifications. Dosimetry
characteristics that are irradiated sequentially to a specified is essential to the irradiation process since it is used to
range of absorbed dose. determine both of these limits and to confirm that the product
is routinely irradiated within these limits.
3.1.13 simulated product—massofmaterialwithabsorption
and scattering properties similar to those of the product, 4.3 The absorbed-dose distribution within the product de-
material, or substance to be irradiated. pends on the overall product dimensions and mass, irradiation
geometry, and source activity distribution.
3.1.13.1 Discussion—Simulated product is used during ir-
4.4 Before an irradiation facility can be used, it must be
radiator characterization as a substitute for the actual product,
material or substance to be irradiated. When used in routine qualified to determine its effectiveness in reproducibly deliv-
ering known, controllable absorbed doses. This involves test-
production runs in order to compensate for the absence of
product, simulated product is sometimes referred to as com- ing the process equipment, calibrating the equipment and
pensating dummy. When used for absorbed-dose mapping, dosimetry system, and characterizing the magnitude, distribu-
simulated product is sometimes referred to as phantom mate- tion and reproducibility of the absorbed dose delivered by the
rial. irradiator for a range of product densities.
3.1.14 timer setting—defined time interval during which 4.5 To ensure consistent and reproducible dose delivery in a
product is exposed to radiation. qualified process, routine process control requires documented
© ISO/ASTM International 2013 – All rights reserved
product handling procedures before and after irradiation, con- 6.4 Because of mechanical speed limitations, various tech-
sistent product loading configuration, control and monitoring niques may be used to reduce the absorbed-dose rates for low
of critical process parameters, routine product dosimetry and
absorbed-dose applications. These techniques include using
documentation of the required activities. only a portion of the source (for example, raising only one of
several source racks to the irradiation position), using attenu-
5. Radiation source characteristics
ators, and irradiating at greater distances from the source.
5.1 The radiation source used in a facility considered in this
60 137
practice consists of sealed elements of Co or Cs which are
7. Dosimetry system calibration
typically linear rods or “pencils” arranged in one or more
7.1 The dosimetry system shall be calibrated in accordance
planar or cylindrical arrays.
with Practice 51261, and the user’s procedures, which should
5.2 A cobalt-60 source emits photons with energies of
specify details of the calibration process and quality assurance
approximately 1.17 and 1.33 MeV in nearly equal proportions.
requirements.
A cesium-137 source emits photons with energies of approxi-
7.2 The dosimetry system calibration is part of a measure-
mately 0.662 MeV (1).
60 137
ment management system.
5.3 The radioactive decay half-lives for Co and Cs are
regularly reviewed and updated. The most recent publication
8. Installation qualification
by the National Institute of Standards and Technology gave
values of 1925.20 (6 0.25) days for Co and 11018.3 (6 9.5)
8.1 Objective—The purpose of an installation qualification
days for Cs (2).
program is to demonstrate that the irradiator with its associated
5.4 Betweensourcereplenishments,removals,orredistribu-
processing equipment and measurement instruments have been
tions, the variation in the source output is solely due to the
delivered and installed in accordance with their specifications.
steady reduction in the activity caused by the radioactive
Installationqualificationincludesdocumentationoftheirradia-
decay.
tor and the associated processing equipment and measurement
instruments, establishment of the testing, operation and cali-
6. Types of facilities
bration procedures for their use, and verification that they
6.1 The design of an irradiator affects the delivery of
operate according to specifications. An effective installation
absorbed dose to a product. Therefore, the irradiator design
qualification program will ensure consistent and correct opera-
should be considered when performing the absorbed-dose
tionoftheirradiatorsoastodelivertherequiredabsorbeddose
measurements described in Sections 9 through 11.
to a product.
6.2 Products may be moved to locations where the irradia-
8.2 Equipment Documentation—Document descriptions of
tion will take place, either while the source is fully shielded
the irradiator and the associated processing equipment and
(batch operation) or while the source is exposed (continuous
measurement instruments installed at the facility. This docu-
operation).
mentation shall be retained for the life of the facility. At a
6.3 Productsmaybetransportedpastthesourceatauniform
minimum, it shall include:
and controlled speed (continuous conveyance), may undergo a
8.2.1 Description of the location of the irradiator within the
seriesofshuffle-dwellcyclesduringwhichproductmovements
operator’s premises in relation to the areas assigned and the
are followed by periods of time during which the irradiation
means established for ensuring the segregation of un-irradiated
container is stationary (shuffle-dwell), or may be irradiated at
products from irradiated products,
fixed locations (stationary).
8.2.2 Description of the operating procedure of the irradia-
6.3.1 The desired absorbed dose for the product is obtained
tor,
by controlling by the conveyor speed (continuous conveyance)
8.2.3 Description of the construction and operation of the
or the timer setting (shuffle-dwell or stationary).
product handling equipment,
6.3.2 For many commercial irradiators, the irradiation con-
tainers move in one or more parallel rows on each side of a 8.2.4 Description of the materials and construction of any
vertical rectangular source array. The irradiation containers
containers used to hold products during irradiation,
may move past a source array in a configuration in which the
8.2.5 Description of the process control system, and
sourceeitherextendsaboveandbelowtheirradiationcontainer
8.2.6 Description of any modifications made during and
(source overlap) or the irradiation container extends above and
after installation.
below the source (product overlap). In the latter configuration,
8.3 Testing, Operation and Calibration Procedures—
the irradiation container moves past the source at two or more
Establish and implement standard operating procedures for the
levels.
testing, operation and calibration (if necessary) of the installed
6.3.2.1 In bulk-flow irradiators, products such as grain or
irradiator and its associated processing equipment and mea-
flour flow in loose form past the source. The desired absorbed
surement instruments.
dose is obtained by controlling the flow rate.
8.3.1 Testing Procedures—These procedures describe the
testing methods used to ensure that the installed irradiator and
its associated processing equipment and measurement instru-
The boldface numbers in parentheses refer to the bibliography at the end of this
practice. ments operate according to specification.
© ISO/ASTM International 2013 – All rights reserved
8.3.2 Operation Procedures—These procedures describe the irradiator expected to be used for irradiating product. The
how to operate the irradiator and its associated processing absorbed dose received by any portion of product in an
equipment and measurement instruments during routine opera- irradiation container depends on the irradiator design, the
tion. source activity and geometry and the process parameters.
8.3.3 Calibration Procedures—These procedures describe
9.1.1 Examples of irradiator design characteristics that af-
periodic calibration and verification methods that ensure that
fect the absorbed dose are the radiation source characteristics,
the installed processing equipment and measurement instru-
source-to-product distance, the irradiation geometry (for ex-
ments continue to operate within specifications. The frequency
ample, 1- or 2-sided irradiation, multiple passes), and the
of calibration for some equipment and instruments might be
irradiator pathways.
specified by a regulatory authority. Some equipment and
9.1.2 Examples of a process parameter are the timer setting
instruments might be required to be traceable to a national or
or conveyor speed.
other accredited standards laboratory.
9.2 Absorbed-dose Mapping—Perform operational qualifi-
8.4 Testing of Processing Equipment and Measurement
cation absorbed-dose mapping to characterize the irradiator
Instruments—Verify that the installed processing equipment
with respect to the dose distribution and reproducibility of
and measurement instruments operate within their design
absorbed-dose delivery. Map the absorbed-dose distribution by
specifications by following the testing procedures noted in
a three-dimensional placement of dosimeter sets in an irradia-
8.3.1. If necessary, ensure that the equipment and instruments
tion container containing homogeneous simulated product. For
have been calibrated according to the calibration procedures
guidance on performing absorbed-dose mapping see ASTM
noted in 8.3.3.
Guide E2303.
8.4.1 Test all processing equipment to verify satisfactory
9.2.1 The amount of homogeneous simulated product in
operation of the irradiator within the design specifications.
each irradiation container should be the amount expected
Document all testing results.
during typical production runs or should be the maximum
8.4.2 Test the performance of the measurement instruments
design volume for the irradiation container.
to ensure that they are functioning according to performance
9.2.2 Select placement patterns to identify the locations of
specifications. Document all testing results.
the absor
...