EN ISO 11704:2018

Water quality - Gross alpha and gross beta activity - Test method using liquid scintillation counting (ISO 11704:2018)

This document specifies a method for the determination of gross alpha and gross beta activity concentration for alpha- and beta-emitting radionuclides using liquid scintillation counting (LSC).
The method is applicable to all types of waters with a dry residue of less than 5 g/l and when no correction for colour quenching is necessary.
Gross alpha and gross beta activity measurement is not intended to give an absolute determination of the activity concentration of all alpha- and beta-emitting radionuclides in a test sample, but is a screening analysis to ensure particular reference levels of specific alpha and beta emitters have not been exceeded. This type of determination is also known as gross alpha and beta index. Gross alpha and beta analysis is not expected to be as accurate nor as precise as specific radionuclide analysis after radiochemical separations.
The method covers non-volatile radionuclides below 80 °C, since some gaseous or volatile radionuclides (e.g. radon and radioiodine) can be lost during the source preparation.
The method is applicable to test samples of drinking water, rain water, surface and ground water as well as cooling water, industrial water, domestic and industrial waste water after proper sampling and test sample preparation (filtration when necessary and taking into account the amount of dissolved material in the water).
The method described in this document is applicable in the event of an emergency situation, because the results can be obtained in less than 4 h by directly measuring water test samples without any treatment.
It is the laboratory's responsibility to ensure the suitability of this test method for the water samples tested.

Wasserbeschaffenheit - Gesamt-Alpha- und Gesamt-Beta-Aktivität - Verfahren mit dem Flüssigszintillationszähler (ISO 11704:2018)

Dieses Dokument legt ein Verfahren zur Bestimmung der Gesamt-Alpha- und Gesamt-Beta-Aktivität durch alpha- und beta-emittierende Radionuklide mittels Flüssigszintillationszählung (en: liquid scintillation counting, LSC) fest.
Das Verfahren ist anwendbar auf alle Wässer mit einem Trockenrückstand von weniger als 5 g/l und wenn keine Korrektur des Farbquenchs erforderlich ist.
Die Messung der Gesamt-Alpha- und Gesamt-Beta-Aktivität ist nicht dafür vorgesehen, eine absolute Bestimmung aller alpha- und beta-strahlenden Radionuklide in einer zu untersuchenden Probe zu leisten, aber als Screeningverfahren ist es geeignet, um sicherzustellen, dass festgelegte Referenzniveaus spezifischer Alpha- und Beta-Strahler nicht überschritten werden. Diese Art der Bestimmung ist auch als Gesamt-Alpha- und Beta-Index bekannt. Von der Gesamt-Alpha- und Beta-Analyse wird nicht erwartet, dass sie genauso akkurat und präzise ist wie die Analyse spezifischer Radionuklide nach radiochemischer Trennung.
Das Verfahren deckt nicht-flüchtige Radionuklide unter 80 °C ab, da einige gasförmige oder flüchtige Radionuklide (z. B. Radon und Radiojod) bei der Aufbereitung der Quelle verloren gehen können.
Das Verfahren ist auf Proben von Trinkwasser, Regenwasser, Oberflächen- und Grundwasser sowie Kühl-wasser, Prozesswasser, häusliches und gewerbliches Abwasser nach geeigneter Probenahme, Proben-behandlung und Aufbereitung der Untersuchungsprobe (Filtration, falls erforderlich, und Berücksichtigung der Menge der im Wasser gelösten Bestandteile) anwendbar.
Das in diesem Dokument beschriebene Verfahren ist in Notfall-Situationen anwendbar, da die Ergebnisse in weniger als 4 h durch direktes Messen der Wasserproben ohne jegliche Vorbehandlung erhalten werden können.
Es liegt in der Verantwortung des Labors, die Eignung dieses Prüfverfahrens für die zu prüfenden Wasser-proben sicherzustellen.

Qualité de l'eau - Activités alpha globale et bêta globale - Méthode d'essai par comptage des scintillations en milieu liquide (ISO 11704:2018)

Le présent document spécifie une méthode de détermination des activités volumiques alpha globale et bêta globale pour des radionucléides émetteurs alpha et bêta par comptage des scintillations en milieu liquide.
La méthode est applicable à tous les types d'eau ayant un résidu sec inférieur à 5 g/l et lorsqu'aucune correction n'est nécessaire pour l'affaiblissement lumineux de couleur.
Le mesurage des activités alpha globale et bêta globale n'est pas destiné à fournir une détermination absolue de l'activité volumique de tous les radionucléides émetteurs alpha et bêta dans un échantillon pour essai; il s'agit plutôt d'une analyse de contrôle visant à s'assurer que des niveaux de référence donnés d'émetteurs alpha et bêta n'ont pas été dépassés. Ce type de déterminations est également connu sous le nom d'indices alpha et bêta. Il ne faut pas s'attendre à ce que l'analyse des activités alpha globale et bêta globale soit aussi précise, ni aussi juste, que l'analyse de radionucléides spécifiques après séparation radiochimique.
Cette méthode couvre les radionucléides non volatils en dessous de 80 °C, étant donné que certains radionucléides gazeux ou volatils (par exemple, le radon et l'iode radioactif) peuvent être perdus lors de la préparation de la solution source.
Cette méthode peut s'appliquer à des échantillons pour essai d'eau potable, d'eau de pluie, d'eau de surface et d'eau souterraine, ainsi que d'eau de refroidissement, d'eaux industrielles, d'eaux usées domestiques et industrielles, après avoir procédé comme il se doit au prélèvement et à la préparation des échantillons pour essai (en les filtrant lorsque cela s'avère nécessaire et en tenant compte de la quantité de matière dissoute dans l'eau).
La méthode décrite dans le présent document est applicable en cas de situation d'urgence, car les résultats peuvent être obtenus en moins de 4 h en mesurant directement les échantillons d'eau pour essai sans aucun traitement.
Il incombe au laboratoire de s'assurer de la pertinence de la présente méthode d'essai pour les échantillons d'eau soumis à essai.

Kakovost vode - Skupna alfa in skupna beta aktivnost - Preskusna metoda s štetjem s tekočinskim scintilatorjem (ISO 11704:2018)

Ta dokument določa metodo za določevanje koncentracije skupne alfa in skupne beta aktivnosti za alfa in beta oddajne radionuklide s štetjem s tekočinskim scintilatorjem (LSC).
Metoda se uporablja za vse vrste vod s suhim ostankom, manjšim od 5 g/l, pri katerih ni potreben
popravek za dušenje fluorescence.
Meritev skupne alfa in skupne beta aktivnosti ni namenjena absolutni določitvi koncentracije aktivnosti vseh alfa in beta oddajnih radionuklidov v preskusnem vzorcu, temveč je presejalna analiza, s katero se zagotovi, da določene referenčne ravni specifičnih alfa in beta oddajnikov
niso bile presežene. Ta vrsta določevanja se imenuje tudi skupni alfa in beta indeks. Ne pričakuje se, da bo skupna alfa
in skupna beta analiza enako točna in natančna kot specifična radionuklidna analiza po radiokemičnih separacijah.
Metoda zajema nehlapne radionuklide s temperaturo, nižjo od 80 °C, saj se lahko nekateri radionuklidi v plinastem stanju oziroma hlapni radionuklidi (npr. radon in radioaktivni jod) med pripravo virov izgubijo.
Metoda se uporablja za preskusne vzorce pitne vode, deževnice, površinske in podtalne vode
ter vode za hlajenje, industrijske vode, gospodinjske in industrijske odpadne vode po ustreznem vzorčenju in pripravi preskusnih vzorcev (filtracija, kadar je to potrebno, in upoštevanje količine raztopljenih snovi v vodi).
Metoda, opisana v tem dokumentu, se uporablja v izrednih razmerah, saj
je mogoče rezultate pridobiti v manj kot štirih urah z neposrednim merjenjem preskusnih vzorcev vode brez obdelave.
Laboratorij mora zagotoviti primernost te preskusne metode za vzorce vode, ki se preskušajo.

General Information

• Status: Published
• Publication Date: 11-Dec-2018
• Withdrawal Date: 29-Jun-2019
• ICS: 13.060.20 - Drinking water
• ICS: 13.060.60 - Examination of physical properties of water
• ICS: 17.240 - Radiation measurements
• Technical Committee: CEN/TC 230 - Water analysis
• Drafting Committee: CEN/TC 230 - Water analysis
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 12-Dec-2018
• Completion Date: 12-Dec-2018
• Ref Project: SIST EN ISO 11704:2019 - Water quality - Gross alpha and gross beta activity - Test method using liquid scintillation counting (ISO 11704:2018)

Relations

• Replaces: EN ISO 11704:2015 - Water quality - Measurement of gross alpha and beta activity concentration in non-saline water - Liquid scintillation counting method (ISO 11704:2010)
• Effective Date: 19-Dec-2018
• Revised: prEN ISO 11704 - Water quality - Gross alpha and gross beta activity - Test method using liquid scintillation counting (ISO/DIS 11704:2025)
• Effective Date: 19-Jun-2024

Overview

EN ISO 11704:2018 - Water quality - Gross alpha and gross beta activity - Test method using liquid scintillation counting specifies a screening method to determine gross alpha and gross beta activity concentrations in water by liquid scintillation counting (LSC). The standard applies to most water types (drinking, rain, surface, ground, cooling, industrial and waste waters) provided the sample has a dry residue < 5 g/L and colour quenching corrections are not required. It covers non‑volatile radionuclides (stable below 80 °C) and is intended as a rapid screening (gross alpha/gross beta index), not a substitute for specific radionuclide analyses after radiochemical separations.

Key topics and requirements

• Scope limits: applicable to waters with dry residue < 5 g/L; excludes volatile radionuclides (e.g., radon, radioiodine) that may be lost during preparation.
• Screening purpose: detects if gross alpha/beta activity levels exceed reference/guidance levels; not an absolute inventory of all radionuclides.
• Measurement methods: direct counting and thermal preconcentration options; includes sample preparation (filtration where necessary) and LSC measurement.
• Calibration & quality control: preparation of alpha/beta calibration sources, blank measurements, determination of alpha and beta efficiencies, and ongoing QC.
• Performance metrics: calculation of activity per mass, standard uncertainty, decision threshold, detection limit and confidence limits are specified.
• Interference controls: addresses contamination, radon ingrowth, and loss of polonium; laboratories must validate suitability for specific sample matrices.
• Emergency use: method can provide results in under 4 hours by direct measurement of water samples, making it suitable for some emergency situations.
• Supporting information: Annex A (set‑up parameters and validation data) and Annex B (method performance under different conditions) provide practical guidance.

Practical applications

• Rapid screening of drinking water, groundwater, surface water and effluents for regulatory compliance and public health protection.
• Emergency response monitoring where fast gross activity screening is required.
• Routine surveillance programs to flag samples requiring further, specific radionuclide analysis.
• Industrial and environmental labs using LSC for radioactivity measurements where quick decision‑making is needed.

Who should use this standard

• Environmental and water quality laboratories performing radioactivity monitoring.
• Public health agencies and water utilities conducting routine or emergency screening.
• Regulatory bodies and consultants assessing compliance with national guidance levels and WHO recommendations.
• Nuclear facility monitoring and industrial operators managing liquid effluents.

Related standards and guidance

• ISO 5667 series (sampling of water) for sampling protocols.
• ISO/IEC Guide 98‑3 (GUM) for uncertainty estimation.
• WHO guidance levels for radionuclides in drinking water.
• ISO 11704 previous edition (2010) and related radioactivity measurement standards.

Keywords: EN ISO 11704:2018, gross alpha, gross beta, liquid scintillation counting, water quality, radioactivity measurements, screening analysis, detection limit, decision threshold, emergency monitoring.

Standards Content (Sample)

SLOVENSKI STANDARD
01-maj-2019
1DGRPHãþD
SIST EN ISO 11704:2015
SIST ISO 11704:2013
.DNRYRVWYRGH6NXSQDDOIDLQVNXSQDEHWDDNWLYQRVW3UHVNXVQDPHWRGDV
ãWHWMHPVWHNRþLQVNLPVFLQWLODWRUMHP,62
Water quality - Gross alpha and gross beta activity - Test method using liquid scintillation
counting (ISO 11704:2018)
Wasserbeschaffenheit - Gesamt-Alpha- und Gesamt-Beta-Aktivität - Verfahren mit dem
Flüssigszintillationszähler (ISO 11704:2018)
Qualité de l'eau - Activités alpha globale et bêta globale - Méthode d'essai par comptage
des scintillations en milieu liquide (ISO 11704:2018)
Ta slovenski standard je istoveten z: EN ISO 11704:2018
ICS:
13.060.60 Preiskava fizikalnih lastnosti Examination of physical
vode properties of water
17.240 Merjenje sevanja Radiation measurements
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 11704
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2018
EUROPÄISCHE NORM
ICS 13.060.60; 17.240 Supersedes EN ISO 11704:2015
English Version
Water quality - Gross alpha and gross beta activity - Test
method using liquid scintillation counting (ISO
11704:2018)
Qualité de l'eau - Activités alpha globale et bêta globale Wasserbeschaffenheit - Gesamt-Alpha- und Gesamt-
- Méthode d'essai par comptage des scintillations en Beta-Aktivität - Verfahren mit dem
milieu liquide (ISO 11704:2018) Flüssigszintillationszähler (ISO 11704:2018)
This European Standard was approved by CEN on 1 November 2018.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey 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
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11704:2018 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 11704:2018) has been prepared by Technical Committee ISO/TC 147 "Water
quality" in collaboration with Technical Committee CEN/TC 230 “Water analysis” the secretariat of
which is held by DIN.
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 June 2019, and conflicting national standards shall be
withdrawn at the latest by June 2019.
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 11704:2015.
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, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 11704:2018 has been approved by CEN as EN ISO 11704:2018 without any modification.

INTERNATIONAL ISO
STANDARD 11704
Second edition
2018-11
Water quality — Gross alpha and gross
beta activity — Test method using
liquid scintillation counting
Qualité de l'eau — Activités alpha globale et bêta globale — Méthode
d'essai par comptage des scintillations en milieu liquide
Reference number
ISO 11704:2018(E)
©
ISO 2018
ISO 11704:2018(E)
© ISO 2018
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
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved

ISO 11704:2018(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, symbols and abbreviated terms . 2
3.1 Terms and definitions . 2
3.2 Symbols and abbreviated terms. 2
4 Principle . 3
5 Reagents and equipment . 3
6 Sampling . 5
7 Procedure. 5
7.1 Direct counting. 5
7.2 Thermal preconcentration . 5
7.3 Sample preparation . 6
7.4 Liquid scintillation measurement . 6
7.4.1 Preparation of alpha and beta calibration sources . 6
7.4.2 Optimization of counting conditions . 6
7.4.3 Blank sample preparation and measurement . 7
7.4.4 Alpha and beta efficiencies . 7
7.4.5 Sample measurement . 8
8 Expression of results . 8
8.1 Calculation of activity per mass. 8
8.2 Standard uncertainty . 9
8.3 Decision threshold .10
8.4 Detection limit .10
8.5 Confidence limits.10
8.6 Quality control .11
9 Interference control .11
9.1 Contamination .11
9.2 Ingrowth of radon .11
9.3 Loss of polonium .11
10 Test report .11
Annex A (informative) Set-up parameters and validation data .13
Annex B (informative) Method performances under different conditions .17
Bibliography .18
ISO 11704:2018(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 documents 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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
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 147, Water quality, Subcommittee SC 3,
Radioactivity measurements.
This second edition cancels and replaces the first edition (ISO 11704:2010), which has been technically
revised. The main changes compared to the previous edition are as follows:
— 5.5.1 has been simplified;
— the application field of this document has been extended to emergency situations;
— slightly different counting conditions have been suggested;
— Annexes A and B have been added.
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.
iv © ISO 2018 – All rights reserved

ISO 11704:2018(E)
Introduction
Radioactivity from several naturally-occurring and anthropogenic sources is present throughout
the environment. Thus, water bodies (e.g. surface waters, ground waters, sea waters) can contain
radionuclides of natural, human-made or both origins:
40 3 14
— natural radionuclides, including K, H, C, and those originating from the thorium and uranium
226 228 234 238 210 210
decay series, in particular Ra, Ra, U, U, Po and Pb, can be found in water for
natural reasons (e.g. desorption from the soil and washoff by rain water) or can be released from
technological processes involving naturally occurring radioactive materials (e.g. the mining and
processing of mineral sands or phosphate fertilizers production and use);
— human-made radionuclides, such as transuranium elements (americium, plutonium, neptunium,
3 14 90
curium), H, C, Sr and gamma emitting radionuclides can also be found in natural waters.
Small quantities of these radionuclides are discharged from nuclear fuel cycle facilities into the
environment as a result of authorized routine releases. Some of these radionuclides used for
medical and industrial applications are also released into the environment after use. Anthropogenic
radionuclides are also found in waters as a result of past fallout contaminations resulting from
the explosion in the atmosphere of nuclear devices and accidents, such as those that occurred in
Chernobyl and Fukushima.
Radionuclide activity concentration in water bodies can vary according to local geological
characteristics and climatic conditions and can be locally and temporally enhanced by releases from
[1]
nuclear installation during planned, existing and emergency exposure situations . Drinking-water
may thus contain radionuclides at activity concentrations, which could present a risk to human health.
The radionuclides present in liquid effluents are usually controlled before being discharged into
[2]
the environment and water bodies. Drinking waters are monitored for their radioactivity as
[3]
recommended by the World Health Organization (WHO) so that proper actions can be taken to ensure
that there is no adverse health effect to the public. Following these international recommendations,
national regulations usually specify radionuclide authorized concentration limits for liquid effluent
discharged to the environment and radionuclide guidance levels for water bodies and drinking waters
for planned, existing and emergency exposure situations. Compliance with these limits can be assessed
[4]
using measurement results with their associated uncertainties as specified by ISO/IEC Guide 98-3
[5]
and ISO 5667-20 .
Depending on the exposure situation, there are different limits and guidance levels that would result
in an action to reduce health risk. As an example, during a planned or existing situation, the WHO
guidelines for guidance level in drinking water is 0,5 Bq/l for gross alpha activity and 1 Bq/l for gross
beta activity.
NOTE The guidance level is the activity concentration with an intake of 2 l/d of drinking water for one year
that results in an effective dose of 0,1 mSv/a for members of the public. This is an effective dose that represents a
[3]
very low level of risk and which is not expected to give rise to any detectable adverse health effects .
Thus, the test method can be adapted so that the characteristic limits, decision threshold, detection
limit and uncertainties ensure that the radionuclide activity concentrations test results can be verified
to be below the guidance levels required by a national authority for either planned/existing situations
[6][7][8]
or for an emergency situation .
Usually, the test methods can be adjusted to measure the activity concentration of the radionuclide(s)
in either waste waters before storage or in liquid effluents before being discharged to the environment.
The test results will enable the plant/installation operator to verify that, before their discharge, waste
waters/liquid effluent radioactive activity concentrations do not exceed authorized limits.
The test method(s) described in this document may be used during planned, existing and emergency
exposure situations as well as for waste waters and liquid effluents with specific modifications that
could increase the overall uncertainty, detection limit and threshold.
ISO 11704:2018(E)
The test method(s) may be used for water samples after proper sampling, sample handling and test
sample preparation (see the relevant part of the ISO 5667 series).
An International Standard on a test method of gross alpha and gross beta activity concentrations in
water samples is justified for test laboratories carrying out these measurements, required sometimes
by national authorities, as laboratories may have to obtain a specific accreditation for radionuclide
measurement in drinking water samples.
This document is one of a set of International Standards on test methods dealing with the measurement
of the activity concentration of radionuclides in water samples.
vi © ISO 2018 – All rights reserved

INTERNATIONAL STANDARD ISO 11704:2018(E)
Water quality — Gross alpha and gross beta activity — Test
method using liquid scintillation counting
WARNING — Persons using this document should be familiar with normal laboratory practice.
This document does not purport to address all of the safety problems, if any, associated with its
use. It is the responsibility of the user to establish appropriate safety and health practices.
IMPORTANT — It is absolutely essential that tests conducted according to this document be
carried out by suitably trained staff.
1 Scope
This document specifies a method for the determination of gross alpha and gross beta activity
concentration for alpha- and beta-emitting radionuclides using liquid scintillation counting (LSC).
The method is applicable to all types of waters with a dry residue of less than 5 g/l and when no
correction for colour quenching is necessary.
Gross alpha and gross beta activity measurement is not intended to give an absolute determination
of the activity concentration of all alpha- and beta-emitting radionuclides in a test sample, but is a
screening analysis to ensure particular reference levels of specific alpha and beta emitters have not
been exceeded. This type of determination is also known as gross alpha and beta index. Gross alpha
and beta analysis is not expected to be as accurate nor as precise as specific radionuclide analysis after
radiochemical separations.
The method covers non-volatile radionuclides below 80 °C, since some gaseous or volatile radionuclides
(e.g. radon and radioiodine) can be lost during the source preparation.
The method is applicable to test samples of drinking water, rain water, surface and ground water as
well as cooling water, industrial water, domestic and industrial waste water after proper sampling and
test sample preparation (filtration when necessary and taking into account the amount of dissolved
material in the water).
The method described in this document is applicable in the event of an emergency situation, because
the results can be obtained in less than 4 h by directly measuring water test samples without any
treatment.
It is the laboratory’s responsibility to ensure the suitability of this test method for the water
samples tested.
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 3696, Water for analytical laboratory use — Specification and test methods
ISO 5667-1, Water quality — Sampling — Part 1: Guidance on the design of sampling programmes and
sampling techniques
ISO 5667-3, Water quality — Sampling — Part 3: Preservation and handling of water samples
ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
ISO 80000-10, Quantities and units — Part 10: Atomic and nuclear physics
ISO 11704:2018(E)
3 Terms, definitions, symbols and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 80000-10 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.2 Symbols and abbreviated terms
For the purposes of this document, the symbols and abbreviated terms defined in ISO 80000-10 and the
following apply.
−1
a , a Alpha and beta activity per mass Bq g
α β
−1
a* Decision threshold Bq g
−1
Detection limit Bq g
a#
−1
Lower and upper limits of the confidence interval Bq g
<>
aa,
A , A Activity of the alpha and beta emitter certified reference solution used Bq
α β
for the α and β calibration sources
m Mass of the test sample g
m Mass of initial sample subject to heating or possibly concentration g
m Mass of heated or concentrated sample g
m Mass of heated or concentrated sample transferred in the vial g
m , m Mass of alpha and beta emitters certified reference solutions, respectively g
Sα Sβ
−1
r , r Sample gross count rate, from the alpha and beta windows, respectively s
gα gβ
−1
r , r , r Blank count rate, from the alpha, beta and total windows, respectively s
0α 0β 0T
−1
r , r , Count rate of the alpha calibration source in the alpha, beta and total s
Sα,α Sα,β
r window
Sα,T
−1
r , r , Count rate of the beta calibration source in the alpha, beta and total s
Sβ,α Sβ,β
r window
Sβ,T
t Sample counting time s
g
t Blank counting time s
t , t Counting time of α and β calibration sources s
sα sβ
−1
u (a) Standard uncertainty associated with the measurement result Bq g
−1
U Expanded uncertainty, calculated from U = ku (a), where k = 1, 2 … Bq g
−1
Standard uncertainty of a as a function of its true value Bq g
  α
ua
()
α
2 © ISO 2018 – All rights reserved

ISO 11704:2018(E)
ε , ε Counting efficiency for alpha and beta, respectively —
α β
τ (χ ) Alpha interference — Fraction of counts observed in the beta window —
α α β
with respect to the total number of counts measured by the counter
when an alpha emitter is measured
τ (χ ) Beta interference — Fraction of counts observed in the alpha window —
β β α
with respect to the total number of counts measured by the counter
when a beta emitter is measured
4 Principle
Gross alpha and beta activity concentrations are determined by using liquid scintillation counting of a
water sample mixed with a scintillation cocktail.
Gross alpha and beta determinations are not absolute determinations of the sample radioactive
contents, but relative determinations referred to a specific alpha or beta emitter which constitutes the
standard calibration sources. These types of determinations are also known as the alpha and beta index
and are usually employed as screening parameters for first assessment of total radioactive content.
The aqueous sample is acidified using nitric acid and heated. Subsequently, water with low salt content
can be thermally concentrated by slow evaporation to improve the method sensitivity. An aliquot of
sample is transferred into a liquid scintillation vial with scintillation cocktail; scintillations from the
vial are then counted by equipment with an alpha and beta discrimination device.
The counter is previously optimized with respect to an alpha and beta discriminator setting and then
calibrated against alpha and beta emitter certified reference solutions. In data evaluation, no correction
for chemical quenching is applied, since the procedure is designed to provide samples with a relatively
constant quench level.
The method does not account for Rn and its short lived progeny and it is not suitable for
H measurement.
When suspended matter is present in significant quantities, a filtration step is required before
acidification.
5 Reagents and equipment
All reagents shall be of recognized analytical grade, except for the scintillation cocktail, and shall not
contain any detectable alpha and beta activity, except for the radioactive certified reference solutions.
5.1 Nitric acid, c(HNO ) = commercially available acid with mass fraction w(HNO ) = (65 to 70) %.
3 3
5.2 Water, ISO 3696, grade 3.
Deionized water can contain detectable amounts of Rn and short lived progeny. It is therefore
strongly recommended to boil water under vigorous stirring and let it stand for one day before use.
Alternatively, use nitrogen flushing for about 1 h for a 2 l sample.
5.3 Scintillation cocktail.
Commercially available scintillation cocktails suitable for alpha and beta discrimination
(e.g. diisopropylnaphthalene-based cocktails), water miscible.
5.4 Volatile organic solvents.
Methanol or ethanol.
ISO 11704:2018(E)
5.5 Certified reference solutions.
5.5.1 General
In general, the experimental parameters (efficiency, alpha and beta optimum discrimination) depend on
alpha and beta energies, thus the choice of alpha and beta emitter certified reference solutions depends
on knowledge of the type of radioactive contaminant likely to be present in the waters being tested
[9]
(see ISO 9696 and Reference [10]).
NOTE More information on metrological traceability can be found in ISO/IEC 17025.
5.5.2 Alpha emitter certified reference solution
The alpha emitter certified reference solution shall not contain any unexpected detectable alpha and
beta activity.
U is a convenient choice when waters
...