SIST EN ISO 18589-3:2024
(Main)Measurement of radioactivity in the environment - Soil - Part 3: Test method of gamma-emitting radionuclides using gamma-ray spectrometry (ISO 18589-3:2023)
Measurement of radioactivity in the environment - Soil - Part 3: Test method of gamma-emitting radionuclides using gamma-ray spectrometry (ISO 18589-3:2023)
This document specifies the identification and the measurement of the activity in soils of a large number of gamma-emitting radionuclides using gamma spectrometry. This non-destructive method, applicable to large-volume samples (up to about 3 l), covers the determination in a single measurement of all the γ-emitters present for which the photon energy is between 5 keV and 3 MeV.
Generic test method and fundamentals using gamma-ray spectrometry are described in ISO 20042.
This document can be applied by test laboratories performing routine radioactivity measurements as a majority of gamma-emitting radionuclides is characterized by gamma-ray emission between 40 keV and 2 MeV.
The method can be implemented using a germanium or other type of detector with a resolution better than 5 keV.
This document addresses methods and practices for determining gamma-emitting radionuclides activity present in soil, including rock from bedrock and ore, construction materials and products, pottery, etc. This includes such soils and material containing naturally occurring radioactive material (NORM) or those from technological processes involving Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM) (e.g. the mining and processing of mineral sands or phosphate fertilizer production and use) as well as of sludge and sediment. This determination of gamma-emitting radionuclides activity is typically performed for the purpose of radiation protection. It is suitable for the surveillance of the environment and the inspection of a site and allows, in case of accidents, a quick evaluation of gamma activity of soil samples. This might concern soils from gardens, farmland, urban or industrial sites that can contain building materials rubble, as well as soil not affected by human activities.
When the radioactivity characterization of the unsieved material above 200 μm or 250 μm, made of petrographic nature or of anthropogenic origin such as building materials rubble, is required, this material can be crushed in order to obtain a homogeneous sample for testing as described in ISO 18589‑2.
Ermittlung der Radioaktivität in der Umwelt - Erdboden - Teil 3: Messung von Gammastrahlen emittierenden Radionukliden mittels Gammaspektrometrie (ISO 18589-3:2023)
Dieses Dokument beschreibt die Bestimmung einer großen Anzahl von Gammastrahlung emittierenden Radio¬nukliden in Böden und die Messung ihrer Aktivität mit Hilfe der Gammaspektrometrie. Dieses zerstörungsfreie Verfahren dient dazu, bei großvolumigen Proben (bis zu etwa 3 l) alle vorhandenen Gamma-Emitter mit einer Photonenenergie zwischen 5 keV und 3 MeV in einer einzigen Messung zu bestimmen.
Ein allgemeines Prüfverfahren und Grundlagen der Messung mit Gammaspektrometrie sind in ISO 20042 beschrieben.
Dieses Dokument kann von Prüflaboren angewendet werden, die routinemäßige Aktivitätsmessungen durch-führen, da für die Mehrzahl der Gamma-Radionuklide die Emission von Gammastrahlung zwischen 40 keV und 2 MeV charakteristisch ist.
Bei diesem Verfahren können Germaniumdetektoren oder andere Detektortypen mit einer Auflösung von bes-ser als 5 keV eingesetzt werden.
Dieses Dokument behandelt Verfahren und Praktiken zur Bestimmung der Aktivität von Gammastrahlung emit¬tierenden Radionukliden im Boden, einschließlich Gestein aus Grundgestein und Erz, Baustoffen und Produk¬ten, Keramik usw. Dies schließt sowohl Böden und Materialien ein, die natürlich vorkommende radio-aktive Stoffe (NORM) oder jene aus technologischen Prozessen, die technologisch verbesserte natürlich vorkom¬mende radioaktive Stoffe (TENORM) einbeziehen (z. B. die Förderung und die Verarbeitung von mineralischen Sanden oder die Produktion und Anwendung von Phosphatdüngemitteln) enthalten, als auch Klärschlamm und Sediment. Diese Bestimmung der Aktivität von Gammastrahlung emittierenden Radio-nukliden geschieht übli¬cherweise zum Zweck des Strahlenschutzes. Es ist für die Überwachung der Umwelt und die Überprüfung von Flächen geeignet und erlaubt im Falle von Unfällen eine schnelle Bestimmung der Gammaaktivität von Boden¬proben. Dabei kann es sich um Erdproben aus Gärten, landwirtschaftlich genutzten, urbanen oder industriellen Geländen, die Bauschutt enthalten, oder um von menschlichen Aktivitäten unbeeinflusste Böden handeln.
Wenn die Feststellung der Radioaktivität von ungesiebten Materialien einer Größe von mehr als 200 μm oder 250 μm erforderlich ist, die petrographischer Art oder anthropogenen Ursprungs wie Bauschutt sind, können diese Materialien zermahlen werden, um eine homogene Probe zu erhalten, wie in ISO 18589 2 beschrieben.
Mesurage de la radioactivité dans l'environnement - Sol - Partie 3: Méthode d'essai des radionucléides émetteurs gamma par spectrométrie gamma (ISO 18589-3:2023)
Le présent document spécifie l’identification et le mesurage de l’activité d’un grand nombre de radionucléides émetteurs gamma, dans des sols, par spectrométrie gamma. Cette méthode non destructive applicable à des échantillons de grand volume (jusqu’à 3 l) permet de déterminer, par un seul mesurage, tous les émetteurs γ présents dont l’énergie des photons est comprise entre 5 keV et 3 MeV.
La méthode d’essai générique et les principes fondamentaux d’utilisation de la spectrométrie gamma sont décrits dans l’ISO 20042.
Le présent document peut être utilisé par les laboratoires d’essai réalisant des mesures de radioactivité en routine, car la majorité des radionucléides émetteurs gamma est caractérisée par des raies d’émission gamma entre 40 keV et 2 MeV.
Cette méthode peut être mise en œuvre en utilisant un germanium ou un autre type de détecteur d’une résolution inférieure à 5 keV.
Le présent document a pour objet les méthodes et les pratiques de détermination de l’activité des radionucléides émetteurs gamma présents dans les sols, notamment dans les roches provenant du socle rocheux et de minerai, les matériaux et les produits de construction, les poteries, etc. Ces sols et matériaux contiennent des matières radioactives naturelles (MRN), ou sont le résultats de procédés technologiques mettant en œuvre des matières radioactives naturelles améliorées technologiquement (MRNAT), telles que l’exploitation minière et le traitement des sables minéraux, la production et l’utilisation d’engrais phosphatés, ainsi que les boues et les sédiments. Utilisée en général dans un but de radioprotection, cette méthode de détermination de l’activité des radionucléides émetteurs gamma est parfaitement adaptée à la surveillance de l’environnement et à l’inspection d’un site et permet, en cas d’accident, une évaluation rapide du niveau de radioactivité gamma. Elle peut concerner les sols de jardins ou des terres agricoles, les sols de sites urbains ou industriels pouvant contenir des débris de matériaux de construction, ainsi que les sols qui n’ont pas été modifiés par des activités humaines.
Lorsque la caractérisation radiologique d’un matériau non tamisé supérieur à 200 μm ou à 250 μm, de nature pétrographique ou d’origine anthropogénique, tels que des débris de matériaux de construction, est nécessaire, ce matériau peut être broyé afin d’obtenir un échantillon homogène pour les essais décrits dans l’ISO 18589‑2.
Merjenje radioaktivnosti v okolju - Tla - 3. del: Preskusna metoda za radionuklide, ki sevajo žarke gama, s spektrometrijo gama (ISO 18589-3:2023)
Ta dokument določa prepoznavanje in merjenje aktivnosti velikega števila radionuklidov, ki sevajo gama žarke, v prsteh z gama spektrometrijo. Ta neporušitvena metoda, ki se uporablja na vzorcih velike prostornine (do približno 3 l), zajema določanje vseh prisotnih sevalcev žarkov γ s fotonsko energijo med 5 keV in 3 MeV z enim merjenjem.
Splošna preskusna metoda in osnove z uporabo gama spektrometrije so opisane v standardu ISO 20042.
Ta dokument lahko uporabljajo preskusni laboratoriji, ki izvajajo rutinske meritve radioaktivnosti, saj je za večino radionuklidov, ki sevajo gama žarke, značilno sevanje gama žarkov med 40 keV in 2 MeV.
Metodo se lahko izvaja z germanijem ali drugo vrsto detektorja z ločljivostjo, boljšo od 5 keV.
Ta dokument obravnava metode in prakse za določanje aktivnosti radionuklidov, ki sevajo gama žarke in so prisotni v prsti, vključno s kamninami iz matične podlage in rude, gradbenih materialov in izdelkov, lončarskih izdelkov itd. To vključuje prsti in material, ki vsebuje naravno prisotni radioaktivni material ali material iz tehnoloških postopkov, ki vključujejo tehnološko okrepljene naravno prisotne radioaktivne materiale (TENORM) (npr. pridobivanje in obdelovanje mineralnega peska ali proizvodnja in uporaba fosfatih gnojil), kot tudi blato in usedline. Določanje aktivnosti radionuklidov, ki sevajo gama žarke, se običajno izvaja za namene zaščite pred sevanjem. Primerno je za nadziranje okolja in preglede območja in omogoča hitro oceno aktivnosti gama žarkov v vzorcih prsti v primeru nesreče. To se lahko nanaša na prst z vrtov in kmetijskih, urbanih ali industrijskih površin, ki lahko vsebujejo gradbeni material grušč, ter prst, na katero človeška dejavnost ne vpliva.
Če je treba določiti lastnosti radioaktivnosti nepresejanega materiala z velikostjo zrn nad 200 μm ali 250 μ petrografskega tipa ali antropogenega izvora, na primer gradbenega materiala grušča, je mogoče ta material zdrobiti, da se pridobi homogen vzorec za preskušanje, kot je opisano v standardu ISO 18589-2.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-maj-2024
Merjenje radioaktivnosti v okolju - Tla - 3. del: Preskusna metoda za radionuklide,
ki sevajo žarke gama, s spektrometrijo gama (ISO 18589-3:2023)
Measurement of radioactivity in the environment - Soil - Part 3: Test method of gamma-
emitting radionuclides using gamma-ray spectrometry (ISO 18589-3:2023)
Ermittlung der Radioaktivität in der Umwelt - Erdboden - Teil 3: Messung von
Gammastrahlen emittierenden Radionukliden mittels Gammaspektrometrie (ISO 18589-
3:2023)
Mesurage de la radioactivité dans l'environnement - Sol - Partie 3: Méthode d'essai des
radionucléides émetteurs gamma par spectrométrie gamma (ISO 18589-3:2023)
Ta slovenski standard je istoveten z: EN ISO 18589-3:2024
ICS:
13.080.01 Kakovost tal in pedologija na Soil quality and pedology in
splošno general
17.240 Merjenje sevanja Radiation measurements
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN ISO 18589-3
EUROPEAN STANDARD
NORME EUROPÉENNE
February 2024
EUROPÄISCHE NORM
ICS 13.080.01; 17.240 Supersedes EN ISO 18589-3:2017
English Version
Measurement of radioactivity in the environment - Soil -
Part 3: Test method of gamma-emitting radionuclides
using gamma-ray spectrometry (ISO 18589-3:2023)
Mesurage de la radioactivité dans l'environnement - Ermittlung der Radioaktivität in der Umwelt -
Sol - Partie 3: Méthode d'essai des radionucléides Erdboden - Teil 3: Messung von Gammastrahlen
émetteurs gamma par spectrométrie gamma (ISO emittierenden Radionukliden mittels
18589-3:2023) Gammaspektrometrie (ISO 18589-3:2023)
This European Standard was approved by CEN on 26 February 2024.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 18589-3:2024 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
European foreword
The text of ISO 18589-3:2023 has been prepared by Technical Committee ISO/TC 85 "Nuclear energy,
nuclear technologies, and radiological protection” of the International Organization for Standardization
(ISO) and has been taken over as EN ISO 18589-3:2024 by Technical Committee CEN/TC 430 “Nuclear
energy, nuclear technologies, and radiological protection” the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by August 2024, and conflicting national standards shall
be withdrawn at the latest by August 2024.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 18589-3:2017.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 18589-3:2023 has been approved by CEN as EN ISO 18589-3:2024 without any
modification.
INTERNATIONAL ISO
STANDARD 18589-3
Third edition
2023-07
Measurement of radioactivity in the
environment — Soil —
Part 3:
Test method of gamma-emitting
radionuclides using gamma-ray
spectrometry
Mesurage de la radioactivité dans l'environnement — Sol —
Partie 3: Méthode d'essai des radionucléides émetteurs gamma par
spectrométrie gamma
Reference number
ISO 18589-3:2023(E)
ISO 18589-3:2023(E)
© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
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Phone: +41 22 749 01 11
Email: copyright@iso.org
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Published in Switzerland
ii
ISO 18589-3:2023(E)
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and symbols . 2
3.1 Terms and definitions . 2
3.2 Symbols . 2
4 Principle . 3
5 Reference sources . 4
5.1 Source(s) for energy calibration . 4
5.2 Reference source(s) for efficiency calibration . 4
5.2.1 General . 4
5.2.2 Reference sources for laboratory gamma spectrometry systems . 4
5.2.3 Reference sources used with numerical methods . 5
6 Gamma spectrometry equipment.5
6.1 General description . 5
6.2 Detector types. 5
6.3 High voltage power supply . 6
6.4 Preamplifier . 6
6.5 Cryostat or electric cooler . 6
6.6 Shielding . 6
6.7 Analogue or digital acquisition electronics . 6
6.7.1 General . 6
6.7.2 Analogue electronic . 7
6.7.3 Digital electronic DSP . 7
6.8 Computer, including peripherical devices and software . 7
7 Nuclear decay data . 8
8 Sample container .8
9 Procedure .8
9.1 Packaging of samples for measuring purposes . 8
9.2 Laboratory background level . 9
9.3 Calibration . 9
9.3.1 Energy calibration. 9
9.3.2 Efficiency calibration . 10
9.4 Correction required for the measurements of natural radionuclides . 11
9.5 Quality control .12
10 Expression of results .12
10.1 Calculation of the activity per unit of mass .12
10.1.1 General .12
10.1.2 Dead time and pile up corrections (see ISO 20042) .12
10.1.3 Decay corrections .13
10.1.4 Self-absorption correction . 13
10.1.5 True coincidence summing . 14
10.2 Standard uncertainty . 15
10.3 Decision threshold . 16
10.4 Detection limit . 16
10.5 Limits of the coverage intervals . 17
10.5.1 Limits of the probabilistically symmetric coverage interval . 17
10.5.2 The shortest coverage interval . 17
10.6 Corrections for contributions from other radionuclides and background . 17
iii
ISO 18589-3:2023(E)
10.6.1 General . 17
10.6.2 Contribution from other radionuclides . 18
10.6.3 Contribution from background . 19
11 Test report .19
Annex A (informative) Analysis of natural radionuclides in soil samples using gamma
spectrometry .21
[21][22]
Annex B (informative) Self-attenuation correction .27
Annex C (informative) True coincidence summing .30
Annex D (informative) Calculation of the activity per unit mass from a gamma spectrum
using a linear background subtraction .32
Bibliography .34
iv
ISO 18589-3:2023(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO document should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use
of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed
patent rights in respect thereof. As of the date of publication of this document, ISO had not received
notice of (a) patent(s) which may be required to implement this document. However, implementers are
cautioned that this may not represent the latest information, which may be obtained from the patent
database available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all
such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 85, Nuclear energy, nuclear technologies,
and radiological protection, Subcommittee SC 2, Radiological protection.
This third edition cancels and replaces the second edition (ISO 18589-3:2015), which has been
technically revised.
The main change is:
— a correction to Formula (4);
A list of all parts in the ISO 18589 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
v
ISO 18589-3:2023(E)
Introduction
Everyone is exposed to natural radiation. The natural sources of radiation are cosmic rays and
naturally occurring radioactive substances which exist in the earth and flora and fauna, including the
human body. Human activities involving the use of radiation and radioactive substances add to the
radiation exposure from this natural exposure. Some of those activities, such as the mining and use
of ores containing naturally-occurring radioactive materials (NORM) and the production of energy
by burning coal that contains such substances, simply enhance the exposure from natural radiation
sources. Nuclear power plants and other nuclear installations use radioactive materials and produce
radioactive effluent and waste during operation and decommissioning. The use of radioactive materials
in industry, agriculture and research is expanding around the globe.
All these human activities give rise to radiation exposures that are only a small fraction of the global
average level of natural exposure. The medical use of radiation is the largest and a growing man-made
source of radiation exposure in developed countries. It includes diagnostic radiology, radiotherapy,
nuclear medicine and interventional radiology.
Radiation exposure also occurs as a result of occupational activities. It is incurred by workers in
industry, medicine and research using radiation or radioactive substances, as well as by passengers
and crew during air travel. The average level of occupational exposures is generally below the global
average level of natural radiation exposure (see Reference [1]).
As uses of radiation increase, so do the potential health risk and the public's concerns. Thus, all these
exposures are regularly assessed in order to:
— improve the understanding of global levels and temporal trends of public and worker exposure;
— evaluate the components of exposure so as to provide a measure of their relative importance;
— identify emerging issues that may warrant more attention and study. While doses to workers are
mostly directly measured, doses to the public are usually assessed by indirect methods using the
results of radioactivity measurements of waste, effluent and/or environmental samples.
To ensure that the data obtained from radioactivity monitoring programs support their intended use, it
is essential that the stakeholders (for example nuclear site operators, regulatory and local authorities)
agree on appropriate methods and procedures for obtaining representative samples and for handling,
storing, preparing and measuring the test samples. An assessment of the overall measurement
uncertainty also needs to be carried out systematically. As reliable, comparable and ‘fit for purpose’
data are an essential requirement for any public health decision based on radioactivity measurements,
international standards of tested and validated radionuclide test methods are an important tool for
the production of such measurement results. The application of standards serves also to guarantee
comparability of the test results over time and between different testing laboratories. Laboratories
apply them to demonstrate their technical competences and to complete proficiency tests successfully
during interlaboratory comparisons, two prerequisites for obtaining national accreditation.
Today, over a hundred International Standards are available to testing laboratories for measuring
radionuclides in different matrices.
Generic standards help testing laboratories to manage the measurement process by setting out the
general requirements and methods to calibrate equipment and validate techniques. These standards
underpin specific standards which describe the test methods to be performed by staff, for example, for
different types of samples. The specific standards cover test methods for:
40 3 14
— naturally-occurring radionuclides (including K, H, C and those originating from the thorium
226 228 234 238 210
and uranium decay series, in particular Ra, Ra, U, U and Pb) which can be found in
materials from natural sources or can be released from technological processes involving naturally
occurring radioactive materials (e.g., the mining and processing of mineral sands or phosphate
fertilizer production and use);
vi
ISO 18589-3:2023(E)
— human-made radionuclides, such as transuranium elements (americium, plutonium, neptunium,
3 14 90
and curium), H, C, Sr and gamma-ray emitting radionuclides found in waste, liquid and gaseous
effluent, in environmental matrices (water, air, soil and biota), in food and in animal feed as a result
of authorized releases into the environment, fallout from the explosion in the atmosphere of nuclear
devices and fallout from accidents, such as those that occurred in Chernobyl and Fukushima.
The fraction of the background dose rate to man from environmental radiation, mainly gamma
radiation, is very variable and depends on factors such as the radioactivity of the local rock and soil, the
nature of building materials and the construction of buildings in which people live and work.
A reliable determination of the activity concentration of gamma-ray emitting radionuclides in various
matrices is necessary to assess the potential human exposure, to verify compliance with radiation
protection and environmental protection regulations or to provide guidance on reducing health risks.
Gamma-ray emitting radionuclides are also used as tracers in biology, medicine, physics, chemistry, and
engineering. Accurate measurement of the activities of the radionuclides is also needed for national
security and in connection with the Non-Proliferation Treaty (NPT).
This document is to be used in the context of a quality assurance management system (ISO/IEC 17025).
ISO 18589 is published in several parts for use jointly or separately according to needs. These parts are
complementary and are addressed to those responsible for determining the radioactivity present in
soil, bedrocks and ore (NORM or TENORM). The first two parts are general in nature and describe the
setting up of programmes and sampling techniques, methods of general processing of samples in the
laboratory (ISO 18589-1), the sampling strategy and the soil sampling technique, soil sample handling
and preparation (ISO 18589-2). ISO 18589-3, ISO 18589-4 and ISO 18589-5 deal with nuclide-specific
test methods to quantify the activity concentration of gamma emitting radionuclides (ISO 18589-3 and
ISO 20042), plutonium isotopes (ISO 18589-4) and Sr (ISO 18589-5) of soil samples. ISO 18589-6
deals with non-specific measurements to quantify rapidly gross alpha or gross beta activities and
ISO 18589-7 describes in situ measurement of gamma-emitting radionuclides.
The test methods described in ISO 18589-3 to ISO 18589-6 can also be used to measure the radionuclides
in sludge, sediment, construction material and products following proper sampling procedure.
This document is one of a set of International Standards on measurement of radioactivity in the
environment.
vii
INTERNATIONAL STANDARD ISO 18589-3:2023(E)
Measurement of radioactivity in the environment — Soil —
Part 3:
Test method of gamma-emitting radionuclides using
gamma-ray spectrometry
1 Scope
This document specifies the identification and the measurement of the activity in soils of a large number
of gamma-emitting radionuclides using gamma spectrometry. This non-destructive method, applicable
to large-volume samples (up to about 3 l), covers the determination in a single measurement of all the
γ-emitters present for which the photon energy is between 5 keV and 3 MeV.
Generic test method and fundamentals using gamma-ray spectrometry are described in ISO 20042.
This document can be applied by test laboratories performing routine radioactivity measurements as
a majority of gamma-emitting radionuclides is characterized by gamma-ray emission between 40 keV
and 2 MeV.
The method can be implemented using a germanium or other type of detector with a resolution better
than 5 keV.
This document addresses methods and practices for determining gamma-emitting radionuclides
activity present in soil, including rock from bedrock and ore, construction materials and products,
pottery, etc. This includes such soils and material containing naturally occurring radioactive material
(NORM) or those from technological processes involving Technologically Enhanced Naturally Occurring
Radioactive Materials (TENORM) (e.g. the mining and processing of mineral sands or phosphate
fertilizer production and use) as well as of sludge and sediment. This determination of gamma-emitting
radionuclides activity is typically performed for the purpose of radiation protection. It is suitable for
the surveillance of the environment and the inspection of a site and allows, in case of accidents, a quick
evaluation of gamma activity of soil samples. This might concern soils from gardens, farmland, urban
or industrial sites that can contain building materials rubble, as well as soil not affected by human
activities.
When the radioactivity characterization of the unsieved material above 200 μm or 250 μm, made
of petrographic nature or of anthropogenic origin such as building materials rubble, is required,
this material can be crushed in order to obtain a homogeneous sample for testing as described in
ISO 18589-2.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 10703, Water quality — Gamma-ray emitting radionuclides — Test method using high resolution
gamma-ray spectrometry
ISO 11074, Soil quality — Vocabulary
ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
ISO 18589-1, Measurement of radioactivity in the environment — Soil — Part 1: General guidelines and
definitions
ISO 18589-3:2023(E)
ISO 20042, Measurement of radioactivity — Gamma-ray emitting radionuclides — Generic test method
using gamma-ray spectrometry
ISO 80000-10, Quantities and units — Part 10: Atomic and nuclear physics
ISO/IEC Guide 98-1, Uncertainty of measurement — Part 1: Introduction to the expression of uncertainty
in measurement
3 Terms, definitions and symbols
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 10703, ISO 11074, ISO 18589-1,
ISO 20042 and ISO 80000-10 apply.
3.2 Symbols
For the purposes of this document, the symbols given in ISO 10703, ISO 11074, ISO 18589-1, ISO 20042
and ISO 80000-10 apply.
Symbol Meaning Unit
A Activity of each radionuclide in calibration source, at the calibration time Bq
-1
a, a Activity per unit of mass of each radionuclide, without and with corrections Bq·kg
c
Efficiency of the detector at energy, E, with the actual measurement geometry
ε
E
f Correction factor considering all necessary corrections
E
Correction factor for self-attenuation at photon energy E
fE()
att
FE Attenuation factor at photon energy E respectively for the sample and the
()
att
sample
standard
FE()
att
standard
f Correction factor for decay for a reference date
d
Correction factor for coincidence losses (summing-out)
f
cl,E
Correction factor for summing-in effects by coincidences
f
su,E
Correction factor for dead time and pile up
f
dt pu,E
h Height of the sample in the container cm
-1
λ
Decay constant of each radionuclide s
2 -1
μ (E) Mass attenuation coefficient, at photon energy, E cm ·g
m
-1
Linear attenuation coefficient at photon energy E respectively for the sample cm
μ ()E ,
sample
and the standard
μ ()E
standard
Number of counts in the net area of the peak, at energy E, in the test sample
nn,,n
NN,,EE0sN ,E
spectrum, in the background spectrum and in the calibration spectrum,
respectively
T
Theoretical number of counts in the net area of the peak, at energy E
n
N,E
Number of counts in the gross area of the peak, at energy E, in the test sample
nn,,n
gg,,EE0sg ,E
spectrum, in the background spectrum and in the calibration spectrum,
respectively
Number of counts in the background of the peak, at energy E, in the test sam-
nn,,n
bb,,EE0sb ,E
ple spectrum in the background spectrum and in the calibration spectrum,
respectively
Probability of the emission of a gamma-ray with energy E of each radionu-
P
E
clide, per decay
-3
ρ Bulk density, in grams per cubic centimetre, of the sample g·cm
ISO 18589-3:2023(E)
Symbol Meaning Unit
S Cross-section of surface
t Test sample spectrum counting time s
g
t Background spectrum counting time s
t Time between the reference time and the start of the measuring time s
i
t Calibration spectrum counting time s
S
-1
u(a), u(a ) Standard uncertainty associated with the measurement result (without and Bq·kg
c
with corrections)
u Relative uncertainty
rel
u Combined uncertainty
c
-1
U Expanded uncertainty calculated with k = 2. Bq·kg
x Unit thickness cm
X Thickness of the sample crossed by a photon flux; it also represents the filling cm
height of the sample in the measurement containers
w Mass fraction of element i (no unit)
i
-1
**
Decision threshold, without and with corrections Bq·kg
aa,
c
-1
##
Detection limit, without and with corrections Bq·kg
aa,
c
-1
Lower and upper limits of the probabilistically symmetric coverage interval Bq·kg
aa,
-1
<>
Lower and upper limits of the shortest coverage interval Bq·kg
aa,
k Quantile of the standardized normal distribution for the probability p (for
p
instance p = 1 − α, 1− β or 1 − γ /2)
k Quantile of the standardized normal distribution for the probability q (for
q
instance q=−12ωγ⋅ / )
φ Distribution function of the standardized normal distribution
ω
Auxiliary quantity
4 Principle
Gamma-rays produce electron-hole pairs when interacting with matter. When a voltage is applied
across a semiconductor detector, these electron hole-pairs are, after proper amplification, detected as
current pulses. The pulse height is related to the energy absorbed from the gamma-photon or photons
in the resolving time of the detector and electronics. By discriminating between the height of the pulses,
a gamma-ray pulse height spectrum is obtained. After analysis of the spectrum, the various peaks
are assigned to the radionuclides which emitted the corresponding gamma rays using an established
detector energy calibration curve.
The activity of gamma-emitting radionuclides present in the soil samples is calculated using the
established energy-dependent detector efficiency curve. These techniques allow the identification and
[2][3]
the quantification of the radionuclides .
The nature and geometry of the detectors as well as the samples call for appropriate energy and
[2][3]
efficiency calibrations . True coincidence summing effects need to be considered, in particular
when analysing samples with high activity levels or in applications with high detections efficiencies
(e.g. when using Marinelli type containers or well-type detectors) or when the sample container is
placed directly on the detector (see 10.1.5).
Fundamentals to gamma-spectrometry, definition and terms and generic description of gamma-
spectrometry equipment are summarized in ISO 20042.
NOTE This part deals exclusively with gamma spectrometry using semiconductor detectors.
ISO 18589-3:2023(E)
5 Reference sources
5.1 Source(s) for energy calibration
The energy calibration of the spectrometer shall be established using one or more sources containing
radionuclides that emit gamma-rays that cover the energy range of interest. Sources can be of any form
but the dead time of the spectrometer for the measurements shall be such that the full energy peak
shape is not distorted and pulse pile-up avoided.
The number of peaks (full energy peaks) required depends on the order of polynomial needed for the
energy vs. channel calibration curve; normally 5 to 10 peaks should be sufficient. Sources containing
152 241 60 137
long-lived radionuclides (for example Eu, Am, Co or Cs) are recommended for this purpose.
For periodical checks of the energy calibration, a smaller number of energy peaks may be used.
5.2 Reference source(s) for efficiency calibration
5.2.1 General
The general method to calibrate the spectrometer is to establish the detection efficiency as a function
of energy for a defined geometry and energy range. One or more reference sources containing single or
multiple radionuclides may be used for this purpose. The activity or emission rates of the radionuclide(s)
in the reference source(s) shall be traceable to national or international standards.
The energies of the emitted gamma-rays shall be distributed over the entire energy range of interest, in
such a way that the energy-dependent efficiency of the spectrometer for the specific geometry can be
determined in a sufficiently accurate way. For most purposes, the accuracy is sufficient for an energy
range of 60 keV to 1 836 keV if a multi-radionuclide source is used containing all or most of the following
241 109 57 139 203 51 113 85 137 54 59 60 65 88
radionuclides: Am, Cd, Co, Ce, Hg, Cr, Sn, Sr, Cs, Mn, Fe, Co, Zn or Y.
For determining the activity of radionuclides emitting gamma-ray or X–rays in the energy region
less than 60 keV, the spectrometry system can be calibrated using a reference source containing the
radionuclides of interest.
It may be necessary to take into account true coincidence summing corrections for the calibration
60 88
radionuclides (for example Co and Y).
5.2.2 Reference sources for laboratory gamma spectrometry systems
Reference sources for laboratory gamma spectrometry systems shall match, as closely as possible, the
geometry, density and matrix composition of the samples to be measured. Reference sources may be
prepared from standardized solutions or purchased as sealed sources. Only standardized solutions or
reference sources that are traceable to national or international primary standards of radioactivity
shall be used.
If no reference materials are available to match the samples, correction factors shall be calculated,
documented and be applied to results from the measurements to take into account differences in
detection efficiency due to geometry, density and matrix effects.
NOTE Reference material used for calibration should be prepared according to ISO 17034.
If a reference source is prepared by dilution from a standardized solution, the supplier’s recommendation
on the chemical form of the diluent shall be followed. It is also recommended that the dispensing process
includes checks for possible losses of active material and on the accuracy of dispensing (for example
gravimetric, volumetric and radiometric techniques should be used and cross-checked).
For this purpose, a calibration source should have the same physical and chemical properties as the
sample. It might, for instance, be produced by spiking an appropriate sample of soil. In this case, it is
essential to ensure the homogeneity of the spiking soil.
ISO 18589-3:2023(E)
5.2.3 Reference sources used with numerical methods
Reference sources for gamma-ray spectrometry systems based on numerical models shall be used
following the manufacturer’s recommendations (see 9.3.2). The activity or the emission rates of the
reference sources shall be traceable to national or international standards.
6 Gamma spectrometry equipment
6.1 General description
The operation of the measurement system is as follows: in semi-conductor detectors, freed charge (the
positive and negative charge carriers, holes and electrons) is generated by the interaction of ionising
radiation with the detector material (through the photoelectric effect, the Compton effect or pair
production). A high-voltage supply applies a bias voltage to the detector crystal resulting in an electric
field. The freed charge is accelerated by the electric field towards the detector electrodes. The collected
charge is converted into an output voltage pulse by a preamplifier and the output pulse is shaped and
amplified by the main amplifier.
Two types of electronic systems can be used to process the signal from the detector preamplifier; an
analogue amplifier combined with digital analogue converter (ADC), or a digital signal processor (DSP)
system. Both systems convert the pulse amplitude and the pulse-height histogram (spectrum) is stored
using a multichannel analyser (MCA). The height of the pulse is proportional to the amount of freed
charge and hence to the energy of the ionising radiation striking the detector.
The spectrum stored by the MCA shows a set of peaks (full energy peaks) superimposed on a
background continuum from scattered radiation. The full energy peaks are approximately Gaussian
in shape. The channel number of the peak centroid depends on the energy of the photon detected. The
net full energy peak area is proportional to the number of photons of that energy that have interacted
with the detector during the counting period (corrected for dead time). The net full energy peak area is
normally determined in the analysis software package by one of two different techniques – summation
or fitting.
For laboratory use, the spectrometer should be located in a facility with stable temperature following
the manufacturer recommendations. It should be noted that changes in temperature can affect the
amplifier gain, changing the energy calibration substantially.
The apparatus shall consist of the following necessary parts from 6.2 to 6.8.
6.2 Detector types
The three main geometries of germanium or other type of detectors available are planar, coaxial and
well-type. Each has specific advantages depending on the circumstances. Coaxial detectors are generally
used with large volume samples, whereas the well-type detectors are most efficient for small volume
samples. Planar detectors can be useful for detecting photons with energies below 200 keV as they can
have better energy resolution than coaxial detectors at these energies. More detailed information on
the detectors is given in ISO 20042:2019, Table D.1.
Microphonics phenomena can result in an increase in the Full Width at Half Maximum (FWHM) of the
full energy peak. It may be necessary to place the detector on an anti-vibration mat.
Depending on the required accuracy and the desired detection limit, it is generally necessary to use
high-quality detectors whose energy resolution is less than 2,2 keV (for the Co peak at 1 332 keV) and
137 [6]
with a peak/Compton ratio between 50 and 80 for Cs (see IEC 61452 ).
210 238 234
Some natural radionuclides (e.g. Pb and U through Th) can be measured only through gamma
lines in
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