ISO 9697
(Main)Water quality — Gross beta activity — Test method using thick source
- Abstract
This document specifies a test method for the determination of gross beta activity concentration in non-saline waters. The method covers non-volatile radionuclides with maximum beta energies of approximately 0,3 MeV or higher. Measurement of low energy beta emitters (e.g. 3H, 228Ra, 210Pb, 14C, 35S and 241Pu) and some gaseous or volatile radionuclides (e.g. radon and radioiodine) might not be included in the gross beta quantification using the test method described in this document. This test method is applicable to the analysis of raw and drinking waters. The range of application depends on the amount of total soluble salts in the water and on the performance characteristics (background count rate and counting efficiency) of the counter used. It is the laboratory's responsibility to ensure the suitability of this method for the water samples tested.
- Status
- Not Published
- Technical Committee
- ISO/TC 147/SC 3 - Radioactivity measurements
- Drafting Committee
- ISO/TC 147/SC 3 - Radioactivity measurements
- Current Stage
- 6000 - International Standard under publication
- Start Date
- 29-Oct-2026
- Completion Date
- 31-Oct-2026
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ISO 9697 is an ISO International Standard for measuring gross beta activity concentration in non-saline water by the thick source method. It is written for laboratories that test raw water and drinking water, and it covers how to prepare the sample, count the source, calculate the result, and report uncertainty and decision limits.
What does ISO 9697 specify?
ISO 9697 specifies a laboratory test method for gross beta activity concentration in non-saline waters, with emphasis on non-volatile radionuclides with maximum beta energies of about 0,3 MeV or higher. It is intended for raw and drinking waters and is organized into clauses on scope, references, terms, symbols, principle, reagents and equipment, procedure, quality assurance and quality control, expression of results, and test report, plus one informative annex.
The method is a screening technique, not a radionuclide-specific separation method. It is therefore used to judge whether the beta activity in a sample is compatible with a chosen reference level, while recognizing that some low-energy beta emitters and some volatile or gaseous radionuclides are outside its practical reach.
What are the key requirements of ISO 9697?
ISO 9697 requires the sample to be taken, preserved and handled according to the ISO 5667 sampling parts, then concentrated, converted to sulfate, baked, and measured on a planchet with a calibrated beta counter. In practice, the whole method depends on preparing a stable, thin and reproducible residue so that the measured count can be linked to the water sample with defensible uncertainty.
Sample handling and applicability
Clause 1 limits the method to non-saline waters and to raw and drinking waters with low total soluble salts. The document also states that it is not suited to rapid, in-the-field analysis because it needs laboratory sample preparation. For a user, that means the method fits routine water laboratories, not field screening kits, and the sample matrix must be checked before use.
The scope also makes clear what the method will not capture well: low-energy beta emitters such as 3H, 228Ra, 210Pb, 14C, 35S and 241Pu, and some gaseous or volatile radionuclides such as radon and radioiodine. That matters because a low result under this method does not mean every beta-emitting radionuclide is absent.
Sample preparation and source making
Clauses 7.1 to 7.6 describe the preparation sequence: filtration immediately after collection, concentration by evaporation, sulfation with sulfuric acid, baking at 350 °C, and transfer of the residue to a planchet. The residue is then dispersed evenly with a volatile solvent, and vinyl acetate may be used to help form a uniform source. In practice, the method works only if the solid source is spread consistently and the mass loading is controlled.
Clause 5 and clause 7.11 stress that sample and calibration source should be as similar as possible in density and radioactivity distribution. The document also notes a low counting surface density for simultaneous gross alpha and beta work, and it recommends matching the mass loading of sample and standard. This is important because source thickness and self-absorption affect the beta count.
Counting, calibration and cross-talk
Clause 6 requires a suitable beta counter, preferably a gas-flow proportional counter, together with a stainless-steel planchet and a furnace that can hold 350 ± 10 °C. Clause 7.9 describes calibration sources prepared from known beta standards such as 40K or 90Sr/90Y, and it also describes the additional alpha calibration source needed when a gas-flow proportional counter is used.
The method includes counting background on a clean planchet and, when relevant, correcting for alpha-beta cross-talk. In practice, that means the laboratory must know how much of the alpha signal leaks into the beta window and must document how the correction was established. If another detector type is used and cross-talk is negligible, the correction can be ignored.
Quality assurance and quality control
Clause 8 requires work to be performed by suitably qualified staff within a quality assurance program such as ISO/IEC 17025. It also requires contamination checks on reagents and on the whole measurement chain, plus verification of the method by intercomparison, reference materials or spiked samples.
Clause 8.3 highlights the influence of natural radionuclides and their ingrowth during storage and between preparation and counting. For the laboratory, this means the counting strategy and timing must be chosen deliberately, because delays can change the apparent gross alpha or gross beta signal.
Results, uncertainty and reporting
Clause 9 gives the calculation framework for activity concentration, standard uncertainty, decision threshold, limit of detection and coverage intervals. The document ties these calculations to ISO 11929-1 and ISO/IEC Guide 98-3, so the result is not just a count rate but a result with a decision rule and uncertainty statement.
Clause 10 requires the report to meet ISO/IEC 17025 and to include the standard reference, sample identification, units, result expression, calculation date and report date. If the limit of detection is higher than the relevant guideline value, the report should record that the method is not suitable for the measurement purpose.
What terms does ISO 9697 define?
- Gross beta activity concentration - the beta activity concentration measured for the water sample without separating individual radionuclides first.
- Gross beta index - another name used in the document for gross beta analysis as a screening measurement.
- Decision threshold - the level used to decide whether the measured activity is statistically distinguishable from background.
- Limit of detection - the lowest activity level that the method can detect with the stated statistical confidence.
- Coverage interval - the interval around the result used to express measurement uncertainty in a probability-based way.
- Planchet - the counting support on which the dried residue is spread for beta measurement.
- Alpha-beta cross-talk - the unwanted contribution of alpha counts into the beta counting window.
- Counting efficiency - the fraction of emitted beta radiation that the counter registers for the chosen calibration source.
Who uses ISO 9697?
ISO 9697 is used by water testing laboratories, radiological monitoring laboratories, drinking water control laboratories, and environmental laboratories that need a gross beta screening result. It is also relevant to quality managers and analysts who must show that the method, uncertainty and reporting approach are suitable for compliance or surveillance work. Buyers and specifiers use it when they need a lab method for routine monitoring of raw water or drinking water against reference levels.
What changed in ISO 9697 from the previous edition?
ISO 9697:2026 is the fifth edition and it cancels and replaces ISO 9697:2018. The changes stated in the document are updated normative references and additional symbols for coverage interval and uncertainty calculations.
Which standards are used with ISO 9697?
| Standard | What it contributes |
|---|---|
| ISO 5667-1 | Guidance on water sampling design and techniques |
| ISO 5667-3 | Preservation and handling of water samples |
| ISO 5667-14 | Quality assurance and quality control for environmental water sampling and handling |
| ISO 11929-1 | Decision threshold, detection limit and coverage interval calculations for ionizing radiation measurements |
| ISO 80000-10 | Quantities and units for atomic and nuclear physics |
| ISO/IEC 17025 | Laboratory competence and the structure of the test report |
| ISO/IEC Guide 98-3 | Expression of measurement uncertainty |
| ISO 5667-20 | Using sampling data for decision making and threshold compliance |
| ISO 9696 | Gross alpha activity by thick source, used when alpha and beta are measured together |
| ISO 9698 | Tritium by liquid scintillation counting |
| ISO 13162 | Carbon 14 by liquid scintillation counting |
| ISO 22908 | Radium 226 and Radium 228 by liquid scintillation counting |
| ISO 11704 | Gross alpha and gross beta activity by liquid scintillation counting |
What does the ISO 9697 document contain?
ISO 9697 contains a full laboratory procedure, from sampling and sample handling through to result calculation and reporting. Clauses 5 to 7 cover the principle, reagents, equipment, concentration, sulfation, baking, source preparation, measurement, background counting, calibration sources and optimization. Clause 8 sets out contamination checks, interference control, method verification and analyst capability checks.
Clause 9 provides the calculation framework for activity concentration, uncertainty, decision threshold, detection limit and coverage intervals. Clause 10 defines the reporting content expected in a test report. Annex A gives an informative example of performance criteria, including validation-style results and precision data for prepared beta sources.
Relations
- Consolidates
FprEN ISO 9697 - Water quality - Gross beta activity - Test method using thick source (ISO/FDIS 9697:2026) - Effective Date
- 12-Feb-2026
- Consolidates
ISO 17555:2021 - Plastics — Film and sheeting — Biaxially oriented polypropylene (PP) films - Effective Date
- 29-Jun-2024
- Effective Date
- 22-Jun-2024
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ISO/FDIS 9697 - Water quality — Gross beta activity — Test method using thick source
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Frequently Asked Questions
ISO 9697 is a draft published by the International Organization for Standardization (ISO). Its full title is "Water quality — Gross beta activity — Test method using thick source". This standard covers: This document specifies a test method for the determination of gross beta activity concentration in non-saline waters. The method covers non-volatile radionuclides with maximum beta energies of approximately 0,3 MeV or higher. Measurement of low energy beta emitters (e.g. 3H, 228Ra, 210Pb, 14C, 35S and 241Pu) and some gaseous or volatile radionuclides (e.g. radon and radioiodine) might not be included in the gross beta quantification using the test method described in this document. This test method is applicable to the analysis of raw and drinking waters. The range of application depends on the amount of total soluble salts in the water and on the performance characteristics (background count rate and counting efficiency) of the counter used. It is the laboratory's responsibility to ensure the suitability of this method for the water samples tested.
This document specifies a test method for the determination of gross beta activity concentration in non-saline waters. The method covers non-volatile radionuclides with maximum beta energies of approximately 0,3 MeV or higher. Measurement of low energy beta emitters (e.g. 3H, 228Ra, 210Pb, 14C, 35S and 241Pu) and some gaseous or volatile radionuclides (e.g. radon and radioiodine) might not be included in the gross beta quantification using the test method described in this document. This test method is applicable to the analysis of raw and drinking waters. The range of application depends on the amount of total soluble salts in the water and on the performance characteristics (background count rate and counting efficiency) of the counter used. It is the laboratory's responsibility to ensure the suitability of this method for the water samples tested.
ISO 9697 is classified under the following ICS (International Classification for Standards) categories: 13.060.60 - Examination of physical properties of water; 13.280 - Radiation protection. The ICS classification helps identify the subject area and facilitates finding related standards.
ISO 9697 has the following relationships with other standards: It is inter standard links to FprEN ISO 9697, ISO 17555:2021, ISO 9697:2018. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
ISO 9697 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
FINAL DRAFT
International
Standard
ISO/FDIS 9697
ISO/TC 147/SC 3
Water quality — Gross beta activity
Secretariat: AFNOR
— Test method using thick source
Voting begins on:
Qualité de l'eau — Activité bêta globale — Méthode d'essai par 2026-09-02
source épaisse
Voting terminates on:
2026-10-28
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO
ISO/CEN PARALLEL PROCESSING LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
Reference number
ISO/FDIS 9697:2026(en) © ISO 2026
FINAL DRAFT
ISO/FDIS 9697:2026(en)
International
Standard
ISO/FDIS 9697
ISO/TC 147/SC 3
Water quality — Gross beta activity
Secretariat: AFNOR
— Test method using thick source
Voting begins on:
Qualité de l'eau — Activité bêta globale — Méthode d'essai par
source épaisse
Voting terminates on:
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
© ISO 2026
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO
ISO/CEN PARALLEL PROCESSING
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
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INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
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MADE IN NATIONAL REGULATIONS.
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Published in Switzerland Reference number
ISO/FDIS 9697:2026(en) © ISO 2026
ii
ISO/FDIS 9697:2026(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 2
5 Principle . 3
6 Chemical reagents and equipment . 3
6.1 Chemical reagents .3
6.2 Equipment .4
7 Procedure . 4
7.1 Sampling .4
7.2 Pre-treatment .5
7.3 Concentration stage .5
7.4 Sulfation stage.5
7.5 Baking stage . .5
7.6 Source preparation .5
7.7 Measurement .6
7.8 Determination of counting background .6
7.9 Preparation of calibration sources .6
7.10 Sensitivity and bias .7
7.11 Optimization of the determination .7
8 Quality assurance and quality control . 7
8.1 General .7
8.2 Contamination check .7
8.3 Interference control of the contribution of the natural radionuclides .7
8.4 Method verification .8
8.5 Demonstration of analyst capability . .8
9 Expression of results . 9
9.1 Calculation of activity concentration .9
9.2 Standard uncertainty .9
9.3 Decision threshold .10
9.4 Limit of detection .10
9.5 Limits of the coverage intervals .11
9.5.1 Limits of the probabilistically symmetric coverage interval .11
9.5.2 Shortest coverage interval .11
10 Test report .12
Annex A (informative) Example of performance criteria .13
Bibliography . 14
iii
ISO/FDIS 9697:2026(en)
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).
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 147, Water quality, Subcommittee SC 3,
Radioactivity measurements, in collaboration with the European Committee for Standardization (CEN)
Technical Committee CEN/TC 230, Water analysis, in accordance with the Agreement on technical
cooperation between ISO and CEN (Vienna Agreement).
This fifth edition cancels and replaces the fourth edition (ISO 9697:2018), which has been technically
revised.
The main changes are as follows:
— the normative references have been updated;
— additional symbols for the coverage interval and uncertainty calculations 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/FDIS 9697:2026(en)
Introduction
Radionuclides are present throughout the environment; thus, water bodies (e.g. surface waters, ground
waters, sea waters) contain radionuclides, which can be of either natural or anthropogenic origin:
3 14 40
— Naturally-occurring radionuclides, including H, C, K and those originating from the thorium and
210 210 222 226 228 227 232 231 234 238
uranium decay series, in particular Pb, Po, Rn, Ra, Ra, Ac, Th, Pa, U, and U,
can be found in water bodies due to either natural processes (e.g. desorption from the soil and runoff
by rainwater) or from technological processes involving naturally occurring radioactive materials
(e.g. mining, mineral processing, oil, gas and coal production, water treatment, production and use of
phosphate fertilisers).
55 59 63 90 99
— Anthropogenic radionuclides such as Fe, Ni, Ni, Sr, Tc, transuranic elements (e.g. Np, Pu,
60 137
Am, Cm) and some gamma emitting radionuclides such as Co and Cs can also be found in natural
waters. Small quantities of anthropogenic radionuclides can be discharged from nuclear facilities to the
environment as a result of authorized routine releases. The radionuclides present in liquid effluents
[1]
are usually controlled before being discharged to the environment and water bodies. Anthropogenic
radionuclides used for medical and industrial applications can be released to the environment after use.
Anthropogenic radionuclides are also found in waters due to contamination from fallout resulting from
above-ground nuclear detonations and accidents such as those that have occurred at the Chernobyl and
Fukushima nuclear facilities.
Radionuclide activity concentrations in water bodies can vary according to local geological characteristics
and climatic conditions and can be locally and temporally enhanced by releases from nuclear facilities
[2][3]
during planned, existing and emergency exposure situations. Some drinking water sources can thus
contain radionuclides at activity concentrations that can present a human health risk. The World Health
[4]
Organization (WHO) recommends to routinely monitor radioactivity in drinking waters and to take
proper actions when needed to minimize the health risk.
National regulations usually specify the activity concentration limits that are authorized in drinking waters,
water bodies and liquid effluents to be discharged to the environment. These limits can vary for planned,
existing and emergency exposure situations. As an example, during either a planned or existing situation,
−1 [ ]
the WHO guidance level for gross beta activity in drinking water is 1,0 Bq·l 4 , see NOTES 1, 2 and 3.
Conformity with these limits is assessed by measuring radioactivity in water samples and by comparing
[12]
the results obtained, with their associated uncertainties, as specified by ISO/IEC Guide 98-3 and
[5]
ISO 5667-20 .
NOTE 1 If the value is not specified in Annex 6 of Reference, [4] the value has been calculated using the formula
provided in Reference [4] and the dose coefficient data from References [6] and [7].
NOTE 2 Gross alpha and gross beta activity are often measured together; the WHO guidance level for gross alpha
−1 [ ]
activity in drinking water is 0,5 Bq·l 4 .
NOTE 3 The guidance level calculated in Reference [4] is the activity concentration that results in a committed
−1 −1
effective dose of 0,1 mSv·a to members of the public for an intake of 2 l·d of drinking water for one year. This is an
effective dose that represents a very low level of risk to human health and which is not expected to give rise to any
[4]
detectable adverse health effects .
This document contains a test method to support laboratories which need to determine the gross beta
activity concentration in water samples. The method(s) described in this document can be used for various
types of waters (see Clause 1). Minor modifications such as sample volume and counting time can be made
if needed to ensure that the decision threshold, detection limit, and uncertainties are below the required
limits. This can be done for several reasons such as emergency situations, lower national guidance limits
and operational requirements.
3 14 228
NOTE 4 This method does not cover low energy beta emitters, such as H, C and Ra or volatile beta emitters
131 [9] [10] [11]
such as I and radon, which are covered in standards such as ISO 9698 , ISO 13162 and ISO 22908 .
v
FINAL DRAFT International Standard ISO/FDIS 9697:2026(en)
Water quality — Gross beta activity — Test method using
thick source
WARNING — Persons using this document shall be familiar with normal laboratory practice. This
document does not purport to address all of the safety issues, if any, associated with its use. It is the
responsibility of the user to establish appropriate safety and health practices.
IMPORTANT — Tests conducted according to this document shall be carried out by suitably trained
staff.
1 Scope
This document specifies a test method for the determination of gross beta activity concentration in non-
saline waters.
This document covers non-volatile radionuclides with maximum beta energies of approximately 0,3 MeV or
higher.
3 228 210 14 35
This document does not apply to the measurement of low-energy beta emitters (e.g. H, Ra, Pb, C, S
and Pu) and some gaseous or volatile radionuclides (e.g. radon and radioiodine).
This document is applicable to the analysis of raw and drinking waters with low amounts of total soluble
salts in the water. The limit of detection depends on the performance characteristics (background count
rate and counting efficiency) of the counter used.
As this method requires sample preparation in laboratory facilities, this method is not suited for rapid, in-
the-field analysis.
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 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 5667-14, Water quality — Sampling — Part 14: Guidance on quality assurance and quality control of
environmental water sampling and handling
ISO 11929-1, Determination of the characteristic limits (decision threshold, detection limit and limits of
the coverage interval) for measurements of ionizing radiation — Fundamentals and application — Part 1:
Elementary applications
ISO 80000-10, Quantities and units — Part 10: Atomic and nuclear physics
ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 80000-10 and ISO 11929-1 apply.
ISO/FDIS 9697:2026(en)
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Symbols
A beta activity in calibration source, at the time of calibration Bq
−1
c beta activity concentration, without and with corrections Bq·l
A
−1
*
Bq·l
decision threshold, without and with corrections
c
A
−1
#
Bq·l
detection limit, without and with corrections
c
A
−1
possible or assumed true quantity values of the measurand Bq·l
c
A
−1
Bq·l
lower limit of the probabilistically symmetric coverage interval
c
A
−1
Bq·l
upper limit of the probabilistically symmetric coverage interval
c
A
−1
<
Bq·l
lower limit of the shortest coverage interval
c
A
−1
>
Bq·l
upper limit of the shortest coverage interval
c
A
quantiles of the standardised normal distribution for the probabilities p (for instance
k
p = 1 , 1 − β or 1− γ / 2 )
p
quantiles of the standardised normal distribution for the probabilities q (for instance
k
q
q = 1 , 1 − β or 1− γ / 2 )
m mass of baked residue from volume, V mg
m mass of the sample residue deposited on the planchet mg
r
−1
r background count rate from the alpha window s
0α
−1
r background count rate from the beta window s
0β
−1
r sample gross count rate from the alpha window s
gα
−1
r sample gross count rate from the beta window s
gβ
−1
r calibration count rate of the alpha source from the alpha window s
sα
−1
r calibration count rate of the beta source from the beta window s
sβ
−1
calibration count rate in the beta window when the alpha calibration source is s
r
sα→β
measured
S surface area of the planchet mm
t background counting time s
t sample counting time s
g
t calibration count time of the alpha and beta sources s
s
−1
u(c ) standard uncertainty associated with the measurement result Bq·l
A
ISO/FDIS 9697:2026(en)
standard uncertainty of the estimator c as a function of an assumed true value c
A
A
uc
A
of the measurand
u (y)relative uncertainty of y
rel
−1
U expanded uncertainty calculated from U = ku(c ), with k = 1, 2 … Bq·l
A
V volume of test sample equivalent to the mass of solid on the planchet l
V volume of the water sample l
t
ε counting efficiency for the specified radioactive standard
−2
mg·mm
ρ surface density of the sample residue deposited on the planchet
s
alpha-beta cross-talk correction factor, i.e. percentage of alpha count going into the %
χ
beta window from the alpha calibration source
5 Principle
Gross beta analysis is a screening method intended to ensure that the activity concentration of some beta
emitters does not exceed specified reference levels. This type of determination is also known as gross beta
index. Gross beta analysis is not expected to be as accurate nor as precise as specific radionuclide analysis
after radiochemical separations. Also, it is not an absolute determination of the activity concentration of all
beta-emitting radionuclides in a test sample.
The sample, taken, handled and preserved as specified in ISO 5667-1, ISO 5667-3 and ISO 5667-14, is evaporated
to almost dryness, converted to the sulfate form, and baked at 350 °C. A portion of the residue is transferred
onto a planchet and the beta activity is measured using a beta counter (e.g. a gas flow proportional counter),
which is calibrated against a suitable beta calibration source, such as potassium-40 ( K) or strontium-90/
90 90
yttrium-90 ( Sr + Y) in equilibrium.
If simultaneous gross alpha and beta measurements are required on the same water sample, the procedure
[13]
specified in this document is very similar to that of ISO 9696 . However, the counting surface density shall
-2[12][15]
be less than 0,1 mg·mm .
A performance criteria example is given in Annex A.
6 Chemical reagents and equipment
6.1 Chemical reagents
All reagents shall be of recognized analytical grade and shall not contain any detectable beta activity.
NOTE A method to prepare reagent blanks and to check for the absence of any inherent beta radioactivity or
contamination is given in Clause 8.
6.1.1 Ultrapure water, with a resistivity of more than 18,2 MΩ∙cm at 25 °C and total organic carbon less
−1
than 1 μg∙l .
Unless otherwise stated, water refers to ultrapure water.
6.1.2 Calibration source, the choice of the beta calibration source depends on the knowledge of the type
90 40
of radioactive contaminant likely to be present in the waters being tested; Sr and K are commonly used.
40 −1 −1 [4]
NOTE The beta activity of K in natural potassium is 27,9 Bq·g , i.e. 14,5 Bq·g in potassium chloride .
−1
6.1.3 Nitric acid, c(HNO ) = 8 mol·l .
ISO/FDIS 9697:2026(en)
−1 −1
6.1.4 Sulfuric acid, c(H SO ) = 18 mol·l , ρ = 1,84 g·ml , mass fraction w(H SO ) = 95 %.
2 4 2 4
6.1.5 Volatile organic solvents, methanol or acetone.
6.1.6 Calcium sulfate, CaSO .
6.1.7 Vinyl acetate [(C H O ) ].
4 6 2 n
226 210
CAUTION — As calcium salts can contain trace amounts of either Ra or Pb, or both, checks for
the presence of these radionuclides shall be made.
6.2 Equipment
Usual laboratory equipment and, in particular, the following:
6.2.1 Beta counter, preferably of the gas-flow proportional type, or otherwise using a plastic scintillation
detector or a silicon-charged particle detector.
When using a gas-flow proportional counter, it is advisable to choose the electronic beta window with a
239 241
minimal beta-alpha cross-talk and correct for the alpha-beta cross-talk using a Pu or Am alpha source.
If an e
...
ISO/FDIS 9697:2026 (en)
ISO/TC 147/SC 3
Secretariat: AFNOR
Date: 2026-08-18
Water quality — Gross beta activity — Test method using thick
source
Fifth edition
Date: 2026-06-1
Qualité de l'eau — Activité bêta globale — Méthode d'essai par source épaisse
FDIS stage
TThhiiss d drraft iaft iss su subbmmiitted tted to to a pa parallearallel vl vote ote iinn IS ISOO, CE, CENN.
ISO/DISFDIS 9697:20252026(en)
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: + 41 22 749 01 11
EmailE-mail: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO/FDIS 9697:2026(en)
iii
ISO/DISFDIS 9697:20252026(en)
Contents
Foreword . v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols . 2
5 Principle . 3
6 Chemical reagents and equipment . 3
6.1 Chemical reagents . 3
6.2 Equipment . 4
7 Procedure . 4
7.1 Sampling . 5
7.2 Pre-treatment . 5
7.3 Concentration stage . 5
7.4 Sulfation stage . 5
7.5 Baking stage . 6
7.6 Source preparation . 6
7.7 Measurement . 6
7.8 Determination of counting background . 6
7.9 Preparation of calibration sources. 6
7.10 Sensitivity and bias . 7
7.11 Optimization of the determination . 7
8 Quality assurance and quality control . 7
8.1 General. 7
8.2 Contamination check . 8
8.3 Interference control of the contribution of the natural radionuclides . 8
8.4 Method verification . 9
8.5 Demonstration of analyst capability . 9
9 Expression of results . 9
9.1 Calculation of activity concentration . 9
9.2 Standard uncertainty. 10
9.3 Decision threshold . 11
9.4 Limit of detection . 11
9.5 Limits of the coverage intervals . 11
10 Test report . 12
Annex A (informative) Example of performance criteria . 14
Bibliography . 15
iv
ISO/FDIS 9697:2026(en)
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).
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 147, Water quality, Subcommittee SC 3,
Radioactivity measurements., in collaboration with the European Committee for Standardization (CEN)
Technical Committee CEN/TC 230, Water analysis, in accordance with the Agreement on technical
cooperation between ISO and CEN (Vienna Agreement).
This fifth edition cancels and replaces the fourth edition (ISO 9697:2018), which has been technically
revised.
The main changes are as follows:
— — the normative references have been updated;
— — additional symbols for the coverage interval and uncertainty calculations 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.
v
ISO/DISFDIS 9697:20252026(en)
Introduction
Radionuclides are present throughout the environment; thus, water bodies (e.g. surface waters, ground
waters, sea waters) contain radionuclides, which can be of either natural or anthropogenic origin:
3 14 40
— — Naturally-occurring radionuclides, including H, C, K, and those originating from the
210 210 222 226 228 227 232 231 234
thorium and uranium decay series, in particular Pb, Po, Rn, Ra, Ra, Ac, Th, Pa, U,
and U, can be found in water bodies due to either natural processes (e.g. desorption from the soil and
runoff by rainwater) or from technological processes involving naturally occurring radioactive materials
(e.g. mining, mineral processing, oil, gas and coal production, water treatment, and production and use of
phosphate fertilisers);).
55 59 63 90 99
— — Anthropogenic radionuclides such as Fe, Ni, Ni, Sr, Tc, transuranic elements (e.g. Np,
60 137
Pu, Am, and Cm) and some gamma emitting radionuclides such as Co and Cs can also be found in
natural waters. Small quantities of anthropogenic radionuclides can be discharged from nuclear facilities
to the environment as a result of authorized routine releases. The radionuclides present in liquid
[1]
effluents are usually controlled before being discharged to the environment[1] and water bodies.
Anthropogenic radionuclides used for medical and industrial applications can be released to the
environment after use. Anthropogenic radionuclides are also found in waters due to contamination from
fallout resulting from above-ground nuclear detonations and accidents such as those that have occurred
at the Chernobyl and Fukushima nuclear facilities.
Radionuclide activity concentrations in water bodies can vary according to local geological characteristics
and climatic conditions and can be locally and temporally enhanced by releases from nuclear facilities during
[2][3]
planned, existing and emergency exposure situations. .[2][3] Some drinking water sources can thus
contain radionuclides at activity concentrations that can present a human health risk. The World Health
[4]
Organization (WHO) recommends to routinely monitor radioactivity in drinking waters[4] and to take
proper actions when needed to minimize the health risk.
National regulations usually specify the activity concentration limits that are authorized in drinking waters,
water bodies and liquid effluents to be discharged to the environment. These limits can vary for planned,
existing and emergency exposure situations. As an example, during either a planned or existing situation, the
−1 [ [4]
WHO guidance level for gross beta activity in drinking water is 1,0 Bq·l [4] ,, see NOTES 1, 2 and 3.
Conformity with these limits is assessed by measuring radioactivity in water samples and by comparing the
results obtained, with their associated uncertainties, as specified by ISO/IEC Guide 98-3[12] and ISO 5667-
[5]
20[5] .
NOTE 1 If the value is not specified in Annex 6 of Reference, [4][4] the value has been calculated using the formula
provided in Reference [4][4] and the dose coefficient data from References [6][6] and[7] [7].
NOTE 2 Gross alpha and gross beta activity are often measured together:; the WHO guidance level for gross alpha
−1 [ [4]
activity in drinking water is 0,5 Bq·l [4] .
NOTE 3 The guidance level calculated in Reference [4][4] is the activity concentration that results in a committed
−1 −1
effective dose of 0,1 mSv·a to members of the public for an intake of 2 l·d of drinking water for one year. This is an
effective dose that represents a very low level of risk to human health and which is not expected to give rise to any
[4]
detectable adverse health effects[4] .
This document contains a test method to support laboratories, which need to determine the gross beta
activity concentration in water samples. The method(s) described in this document can be used for various
types of waters (see 1Clause 1).). Minor modifications such as sample volume and counting time can be
made if needed to ensure that the decision threshold, detection limit, and uncertainties are below the
required limits. This can be done for several reasons such as emergency situations, lower national guidance
limits and operational requirements.
vi
ISO/FDIS 9697:2026(en)
3 14 228
NOTE 4 This method does not cover low energy beta emitters, such as H, C and Ra or volatile beta emitters such
131 [9] [10] [11]
as I and radon, which are covered in standards such as ISO 9698[9], , ISO 13162[10] and ISO 22908[11], .
vii
DRAFT International Standard ISO/DIS 9697:2026(en)
Water quality — Gross beta activity — Test method using thick
source
WARNING — Persons using this document shall be familiar with normal laboratory practice. This
document does not purport to address all of the safety issues, 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 testsTests conducted in accordance withaccording to
this document shall be carried out by suitably qualifiedtrained staff.
1 Scope
This document specifies a test method for the determination of gross beta activity concentration in non-
saline waters. The method covers non-volatile radionuclides with maximum beta energies of approximately
0,3 MeV or higher.
This document covers non-volatile radionuclides with maximum beta energies of approximately 0,3 MeV or
higher.
3 228 210 14 35
This document does not apply to the measurement of low-energy beta emitters (e.g. H, Ra, Pb, C, S
and Pu) and some gaseous or volatile radionuclides (e.g. radon and radioiodine).
This test methoddocument is applicable to the analysis of raw and drinking waters with low amounts of total
soluble salts in the water. LimitThe limit of detection depends on the performance characteristics
(background count rate and counting efficiency) of the counter used.
It is the laboratory’s responsibility to ensure the suitability of this method for the water samples tested. As
this method requires sample preparation in laboratory facilities, this method is not suited for rapid, in-the-
field analysis.
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 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 5667--14, Water quality — Sampling — Part 14: Guidance on quality assurance and quality control of
environmental water sampling and handling
ISO 11929-1, Determination of the characteristic limits (decision threshold, detection limit and limits of the
coverage interval) for measurements of ionizing radiation — Fundamentals and application –— Part 1:
Elementary applications
ISO 80000--10, Quantities and units — Part 10: Atomic and nuclear physics
ISO/DISFDIS 9697:20252026(en)
ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
ISO/IEC Guide 98-3, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in
measurement (GUM:1995)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 80000-10 and ISO 11929-1 apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— — ISO Online browsing platform: available at https://www.iso.org/obp
— — IEC Electropedia: available at https://www.electropedia.org/
4 Symbols
A beta activity in calibration source, at the time of calibration Bq
−1
c beta activity concentration, without and with corrections Bq·l
A
−1
Bq·l
decision threshold, without and with corrections
−1
Bq·l
detection limit, without and with corrections
−1
Bq·l
possible or assumed true quantity values of the measurand
−1
Bq·l
lower limit of the probabilistically symmetric coverage interval
−1
Bq·l
upper limit of the probabilistically symmetric coverage interval
−1
Bq·l
lower limit of the shortest coverage interval
−1
Bq·l
upper limit of the shortest coverage interval
quantiles of the standardised normal distribution for the probabilities p (for
instance p = , , 1 − β or 1− ) )
quantiles of the standardised normal distribution for the probabilities q (for
instance q = , 1 − β or 1− )
quantiles of the standardised normal distribution for the probabilities q (for instance
k
q
/2
q = 1− , 1 − β or 1− )
m mass of baked residue from volume, V mg
m mass of the sample residue deposited on the planchet mg
r
−1
r background count rate from the alpha window s
0α
−1
r background count rate from the beta window s
0β
−1
r sample gross count rate from the alpha window s
gα
−1
r sample gross count rate from the beta window s
gβ
−1
r calibration count rate of the alpha source from the alpha window s
sα
−1
r calibration count rate of the beta source from the beta window s
sβ
−1
calibration count rate in the beta window when the alpha calibration source is s
r
sα→β
measured
ISO/FDIS 9697:2026(en)
S surface area of the planchet mm
t background counting time s
t sample counting time s
g
t calibration count time of the alpha and beta sources s
s
−1
u(c ) standard uncertainty associated with the measurement result Bq·l
A
standard uncertainty of the estimator c as a function of an assumed true value
A
of the measurand
u (y) relative uncertainty of y
rel
−1
U expanded uncertainty calculated from U = ku(c ), with k = 1, 2 … Bq·l
A
V volume of test sample equivalent to the mass of solid on the planchet l
V volume of the water sample l
t
ε counting efficiency for the specified radioactive standard
−2
mg·mm
surface density of the sample residue deposited on the planchet
alpha-beta cross-talk correction factor, i.e. percentage of alpha count going into the %
χ
beta window from the alpha calibration source
5 Principle
Gross beta analysis is a screening method intended to ensure that the activity concentration of some beta
emitters does not exceed specified reference levels. This type of determination is also known as gross beta
index. Gross beta analysis is not expected to be as accurate nor as precise as specific radionuclide analysis
after radiochemical separations. Also, it is not an absolute determination of the activity concentration of all
beta-emitting radionuclides in a test sample.
The sample, taken, handled and preserved as specified in ISO 5667-1, ISO 5667-3 and ISO 5667-14, is
evaporated to almost dryness, converted to the sulfate form, and baked at 350 °C. A portion of the residue is
transferred onto a planchet and the beta activity is measured using a beta counter (e.g. a gas flow
proportional counter), which is calibrated against a suitable beta calibration source, such as potassium-
40 90 90
40 ( K) or strontium-90/yttrium-90 ( Sr + Y) in equilibrium.
If simultaneous gross alpha and beta measurements are required on the same water sample, the procedure
specified in this document is very similar to that of ISO 9696[13][13]. However, the counting surface density
-2[
shall be less than 0,1 mg··mm [12][15][12][15].
A performance criteria example is given in Annex AAnnex A.
6 Chemical reagents and equipment
6.1 Chemical reagents
All reagents shall be of recognisedrecognized analytical grade and shall not contain any detectable beta
activity.
NOTE A method to prepare reagent blanks and to check for the absence of any inherent beta radioactivity or
contamination is given in 8Clause 8.
6.1.1 6.1.1 Ultrapure water, with a resistivity of more than 18,2 MΩ∙cm at 25 °C and total organic
−1
carbon less than 1 μg∙l .
ISO/DISFDIS 9697:20252026(en)
Unless otherwise stated, water refers to ultrapure water.
6.1.2 6.1.2 Calibration source, the choice of the beta calibration source depends on the knowledge of
90 40
the type of radioactive contaminant likely to be present in the waters being tested; Sr and K are
commonly used.
40 −1 −1 [4]
NOTE The beta activity of K in natural potassium is 27,9 Bq·g , i.e. 14,5 Bq·g in potassium chloride[4] .
−1
6.1.3 6.1.3 Nitric acid, c(HNO ) = 8 mol·l .
−1 −1
6.1.4 6.1.4 Sulfuric acid, c(H SO ) = 18 mol·l , ρ = 1,84 g·ml , mass fraction w(H SO ) = 95 %.
2 4 2 4
6.1.5 6.1.5 Volatile organic solvents, methanol or acetone.
6.1.6 6.1.6 Calcium sulfate, CaSO .
6.1.7 6.1.7 Vinyl acetate, [(C H O ) ].
4 6 2 n
226 210
CAUTION — — As calcium salts can contain trace amounts of either Ra or Pb, or both, checks for
the presence of these radionuclides shall be made.
6.2 Equipment
Usual laboratory equipment and, in particular, the following:
6.2.1 6.2.1 Beta counter, preferably of the gas-flow proportional type, or otherwise using a plastic
scintillation detector or a silicon-charged particle detector.
When using a gas-flow proportional counter, it is advisable to choose the electronic beta window with a
239 241
minimal beta-alpha cross-talk and correct for the alpha-beta cross-talk using a Pu or Am alpha source. If
an equipment other than a gas-flow proportional counter is used, then the cross-talk can be insignificant and
ignored.
If a windowless gas-flow proportional counter is used, carry out regular checks for possible contamination of
the counting system by counting blank samples.
NOTE The particulate nature of the source that is intended to be counted can give rise to contamination if operated
in a vacuum (as in the case of silicon-charged particle detector) or gas-flow systems (as used in a proportional counter).
6.2.2 6.2.2 Planchet with counting tray, large enough for a deposited sample of a surface density of at
−2 −2
least 2,5 mg·mm (250 mg·cm ), having a lipped edge and made of stainless steel.
The diameter of the planchet that is intended to be used is determined by the counter requirements, i.e. the
detector diameter and source holder dimensions.
NOTE Even spreading of the prepared solid source material onto the planchet is required and some analysts find it
easier to produce this on a polished metal surface, whereas others prefer to use an etched or roughened planchet (sand
blasting and chemical etching has been applied for this purpose).
6.2.3 6.2.3 Muffle furnace, capable of being maintained at (350 ± 10) °C.
6.2.4 6.2.4 Chromatographic reagent grade silica gel, with 0,1 · ·S ± 1 for contamination check.
7 Procedure
WARNING — The use of this document can involve hazardous materials, operations and equipment.
This document does not purport to address all the safety problems associated with its use. It is the
----------
...
PROJET FINAL
Norme
internationale
ISO/FDIS 9697
ISO/TC 147/SC 3
Qualité de l'eau — Activité bêta
Secrétariat: AFNOR
globale — Méthode d'essai par
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PROJET FINAL
ISO/FDIS 9697:2026(fr)
Norme
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ISO/FDIS 9697
ISO/TC 147/SC 3
Qualité de l'eau — Activité bêta
Secrétariat: AFNOR
globale — Méthode d'essai par
Début de vote:
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Water quality — Gross beta activity — Test method using thick
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ii
ISO/FDIS 9697:2026(fr)
Sommaire Page
Avant-propos .iv
Introduction .v
1 Domaine d'application . 1
2 Références normatives . 1
3 Termes et définitions . 2
4 Symboles . 2
5 Principe. 3
6 Réactifs chimiques et appareillage . 3
6.1 Réactifs chimiques .3
6.2 Appareillage .4
7 Mode opératoire . 5
7.1 Échantillonnage .5
7.2 Prétraitement .5
7.3 Étape de concentration .5
7.4 Étape de sulfatation .5
7.5 Étape de calcination .6
7.6 Préparation de la source .6
7.7 Mesurage .6
7.8 Détermination du bruit de fond de comptage .6
7.9 Préparation des sources d'étalonnage .7
7.10 Sensibilité et biais .7
7.11 Optimisation de la détermination .7
8 Assurance qualité et contrôle qualité . 8
8.1 Généralités .8
8.2 Contrôle de contamination .8
8.3 Contrôle d'interférences de la contribution des radionucléides naturels .8
8.4 Vérification de la méthode .9
8.5 Démonstration de l'aptitude de l'analyste .9
9 Expression des résultats . 9
9.1 Calcul de l'activité volumique.9
9.2 Incertitude-type .10
9.3 Seuil de décision .10
9.4 Limite de détection .11
9.5 Limites des intervalles élargis .11
9.5.1 Limites de l'intervalle élargi probabilistiquement symétrique .11
9.5.2 Intervalle élargi le plus court . 12
10 Rapport d'essai .12
Annexe A (informative) Exemple de critères de performance . 14
Bibliographie .15
iii
ISO/FDIS 9697:2026(fr)
Avant-propos
L'ISO (Organisation internationale de normalisation) est une fédération mondiale d'organismes nationaux
de normalisation (comités membres de l'ISO). L'élaboration des Normes internationales est en général
confiée aux comités techniques de l'ISO. Chaque comité membre intéressé par une étude a le droit de faire
partie du comité technique créé à cet effet. Les organisations internationales, gouvernementales et non
gouvernementales, en liaison avec l'ISO participent également aux travaux. L'ISO collabore étroitement avec
la Commission électrotechnique internationale (IEC) en ce qui concerne la normalisation électrotechnique.
Les procédures utilisées pour élaborer le présent document et celles destinées à sa mise à jour sont
décrites dans les Directives ISO/IEC, Partie 1. Il convient, en particulier de prendre note des différents
critères d'approbation requis pour les différents types de documents ISO. Le présent document
a été rédigé conformément aux règles de rédaction données dans les Directives ISO/IEC, Partie 2
(voir www.iso.org/directives).
L'ISO attire l'attention sur le fait que la mise en application du présent document peut entraîner l'utilisation
d'un ou de plusieurs brevets. L'ISO ne prend pas position quant à la preuve, à la validité et à l'applicabilité de
tout droit de brevet revendiqué à cet égard. À la date de publication du présent document, l'ISO n'avait pas
reçu notification qu'un ou plusieurs brevets pouvaient être nécessaires à sa mise en application. Toutefois,
il y a lieu d'avertir les responsables de la mise en application du présent document que des informations
plus récentes sont susceptibles de figurer dans la base de données de brevets, disponible à l'adresse
www.iso.org/brevets. L'ISO ne saurait être tenue pour responsable de ne pas avoir identifié tout ou partie de
tels droits de brevet.
Les appellations commerciales éventuellement mentionnées dans le présent document sont données pour
information, par souci de commodité, à l'intention des utilisateurs et ne sauraient constituer un engagement.
Pour une explication de la nature volontaire des normes, la signification des termes et expressions
spécifiques de l'ISO liés à l'évaluation de la conformité, ou pour toute information au sujet de l'adhésion de
l'ISO aux principes de l'Organisation mondiale du commerce (OMC) concernant les obstacles techniques au
commerce (OTC), voir www.iso.org/avant-propos.
Le présent document a été élaboré par le comité technique ISO/TC 147, Qualité de l'eau, sous-comité SC 3,
Mesurages de la radioactivité, en collaboration avec le comité technique CEN/TC 230, Analyse de l'eau du
Comité européen de normalisation (CEN), conformément à l'Accord de coopération technique entre l'ISO et
le CEN (Accord de Vienne).
Cette cinquième édition annule et remplace la quatrième édition (ISO 9697:2018), qui a fait l'objet d'une
révision technique.
Les principales modifications sont les suivantes:
— mise à jour des références normatives;
— ajout de symboles supplémentaires pour les calculs de l'intervalle élargi et de l'incertitude.
Il convient que l'utilisateur adresse tout retour d'information ou toute question concernant le présent
document à l'organisme national de normalisation de son pays. Une liste exhaustive desdits organismes se
trouve à l'adresse www.iso.org/fr/members.html.
iv
ISO/FDIS 9697:2026(fr)
Introduction
Les radionucléides sont présents partout dans l'environnement. Dès lors, les masses d'eau (par exemple les
eaux de surface, les eaux souterraines, les eaux de mer) contiennent des radionucléides d'origine naturelle
ou anthropique:
3 14 40
— les radionucléides naturels, y compris H, C, K et ceux provenant des chaînes de désintégration du
210 210 222 226 228 227 232 231 234 238
thorium et de l'uranium, notamment Pb, Po, Rn, Ra, Ra, Ac, Th, Pa, U ou U,
peuvent se trouver dans les masses d'eau en raison de processus naturels (par exemple, la désorption
par le sol ou le lessivage par les eaux pluviales) ou de procédés technologiques mettant en œuvre des
matières radioactives existant à l'état naturel (par exemple, l'extraction minière, le traitement de sables
minéraux, la production de carburant, de gaz ou de charbon, le traitement des eaux, la production et
l'utilisation d'engrais phosphatés);
55 59 63 90 99
— les radionucléides engendrés par l'activité humaine, tels que Fe, Ni, Ni, Sr, Tc, mais aussi
des éléments transuraniens (américium, plutonium, neptunium, curium, par exemple) et certains
60 137
radionucléides émetteurs gamma tels que Co et Cs peuvent également être présents dans les
eaux naturelles. De petites quantités de radionucléides sont rejetées dans l'environnement par les
installations du cycle du combustible lors des rejets périodiques autorisés. Les radionucléides présents
[1]
dans les effluents liquides sont habituellement contrôlés avant d'être déversés dans l'environnement
et les masses d'eau. Des radionucléides, utilisés dans le cadre d'applications médicales et industrielles,
sont également libérés dans l'environnement après usage. Les radionucléides d'origine anthropique sont
aussi présents dans les eaux du fait de contaminations par retombées d'éléments radioactifs rejetés dans
l'atmosphère lors de l'explosion de dispositifs nucléaires ou lors d'accidents nucléaires, tels que ceux de
Tchernobyl et de Fukushima.
Les activités volumiques des radionucléides dans les masses d'eau sont variables en fonction des
caractéristiques géologiques et des conditions climatiques locales, et peuvent être renforcées localement
et dans le temps par les rejets d'installations nucléaires dans des situations d'exposition planifiée,
[2][3]
d'exposition d'urgence et d'exposition existante . Certaines sources d'eau potable peuvent donc contenir
des radionucléides à des activités volumiques susceptibles de présenter un risque sanitaire pour l'Homme.
L'Organisation mondiale de la santé (OMS) recommande une surveillance régulière de la radioactivité des
[4]
eaux potables et la mise en place d'actions adéquates si besoin est afin de limiter le plus possible le risque
pour la santé humaine.
Les législations nationales spécifient généralement les limites autorisées d'activité volumique dans les eaux
potables, les masses d'eau et les effluents liquides rejetés dans l'environnement. Ces limites sont susceptibles
de varier dans le cas de situations d'exposition planifiée, existante ou d'urgence. À titre d'exemple, lors d'une
situation planifiée ou existante, la limite indicative donnée par l'OMS pour l'activité bêta globale dans l'eau
−1 [4]
potable est de 1,0 Bq·l , voir les NOTES 1, 2 et 3. La conformité à ces limites peut être évaluée à partir
des résultats de mesure d'échantillons d'eau et des incertitudes qui y sont associées, tel que précisé par le
[12] [5]
Guide 98-3 de l'ISO/IEC et l'ISO 5667-20 .
NOTE 1 Si cette valeur n'est pas précisée dans l'Annexe 6 de la Référence [4], elle est calculée à l'aide de l'équation
donnée dans la Référence [4] et du coefficient de dose des Références [6] et [7].
NOTE 2 L'activité alpha globale et l'activité bêta globale sont souvent mesurées ensemble; la limite indicative
−1 [4]
donnée par l'OMS pour l'activité alpha globale dans l'eau potable est de 0,5 Bq·l .
NOTE 3 La limite indicative calculée par la Référence [4] correspond à l'activité volumique pour une consommation
−1 −1
de 2 l·j d'eau potable pendant un an, aboutissant à une dose effective engagée de 0,1 mSv·a pour un individu moyen.
Cette dose effective présente un niveau de risque très faible qui ne devrait pas entraîner d'effets indésirables et
[4]
détectables pour la santé .
Le présent document décrit une méthode d'essai pour répondre aux besoins des laboratoires qui déterminent
l'activité volumique bêta globale dans les échantillons d'eau. Les méthodes décrites dans le présent document
peuvent être appliquées à divers types d'eaux (voir l’Article 1). Il est possible d'apporter des modifications
mineures, par exemple au volume d'un échantillon ou à la durée de comptage, afin de s'assurer que le seuil
de décision, la limite de détection et les incertitudes sont inférieures aux limites requises. Ces modifications
v
ISO/FDIS 9697:2026(fr)
peuvent être effectuées dans le cadre d'une situation d'urgence, de limites indicatives nationales inférieures
et d'obligations opérationnelles, etc.
3 14 228
NOTE 4 Cette méthode ne couvre pas les émetteurs bêta à faible énergie, tels que H, C et Ra, ni les émetteurs
131 [9] [10]
bêta volatils tels que I et le radon, qui sont couverts par des normes telles que l'ISO 9698, l'ISO 13162 et
[11]
l'ISO 22908 .
vi
PROJET FINAL Norme internationale ISO/FDIS 9697:2026(fr)
Qualité de l'eau — Activité bêta globale — Méthode d'essai
par source épaisse
AVERTISSEMENT — Les utilisateurs du présent document doivent maîtriser les pratiques courantes
de laboratoire. Le présent document ne prétend pas aborder la totalité des aspects liés à la sécurité
qui pourraient découler de son utilisation. Il incombe à l'utilisateur d'établir des pratiques
appropriées en matière d'hygiène et de sécurité.
IMPORTANT — Les essais réalisés conformément au présent document doivent être effectués par du
personnel ayant reçu une formation adéquate.
1 Domaine d'application
Le présent document spécifie une méthode d'essai permettant de déterminer l'activité volumique bêta
globale des eaux non salines.
Le présent document couvre les radionucléides non volatils émetteurs bêta avec des énergies maximales
d'environ 0,3 MeV ou plus élevées.
Le présent document ne s'applique pas au mesurage des émetteurs bêta à faible énergie (par exemple, H,
228 210 14 35 241
Ra, Pb, C, S et Pu) et de certains radionucléides gazeux ou volatils (par exemple, radon et iode
radioactif).
Le présent document est applicable à l'analyse des eaux brutes et potables présentant de faibles teneurs en
sels solubles totaux. La limite de détection dépend des caractéristiques de performance (taux de comptage
du bruit de fond et efficacité de comptage) du compteur utilisé.
Cette méthode exigeant une préparation des échantillons dans les locaux du laboratoire, cette méthode n'est
pas adaptée à une analyse rapide sur site.
2 Références normatives
Les documents suivants sont cités dans le texte de sorte qu'ils constituent, pour tout ou partie de leur
contenu, des exigences du présent document. Pour les références datées, seule l'édition citée s'applique. Pour
les références non datées, la dernière édition du document de référence s'applique (y compris les éventuels
amendements).
ISO 5667-1, Qualité de l’eau — Échantillonnage — Partie 1: Recommandations relatives à la conception des
programmes et des techniques d’échantillonnage
ISO 5667-3, Qualité de l’eau — Échantillonnage — Partie 3: Conservation et manipulation des échantillons d’eau
ISO 5667-14, Qualité de l'eau — Échantillonnage — Partie 14: Lignes directrices sur l'assurance qualité et le
contrôle qualité pour l'échantillonnage et la manutention des eaux environnementales
ISO 11929-1, Détermination des limites caractéristiques (seuil de décision, limite de détection et limites de
l’intervalle élargi) pour mesurages de rayonnements ionisants — Principes fondamentaux et applications —
Partie 1: Applications élémentaires
ISO 80000-10, Grandeurs et unités — Partie 10: Physique atomique et nucléaire
ISO/IEC 17025, Exigences générales concernant la compétence des laboratoires d'étalonnages et d'essais
ISO/FDIS 9697:2026(fr)
3 Termes et définitions
Pour les besoins du présent document, les termes et définitions de l'ISO 80000-10 et l'ISO 11929-1 s'appliquent.
L'ISO et l'IEC tiennent à jour des bases de données terminologiques destinées à être utilisées en normalisation,
consultables aux adresses suivantes:
— ISO Online browsing platform: disponible à l'adresse https:// www .iso .org/ obp
— IEC Electropedia: disponible à l'adresse https:// www .electropedia .org/
4 Symboles
A activité bêta dans la source d'étalonnage au moment de l'étalonnage Bq
−1
c activité bêta volumique, sans et avec corrections Bq·l
A
−1
∗
Bq·l
seuil de décision, sans et avec corrections
c
A
−1
#
Bq·l
limite de détection, sans et avec corrections
c
A
−1
Bq·l
valeurs vraies possibles ou présumées du mesurande
c
A
−1
Bq·l
limite inférieure de l'intervalle élargi probabilistiquement symétrique
c
A
−1
Bq·l
limite supérieure de l'intervalle élargi probabilistiquement symétrique
c
A
−1
<
Bq·l
limite inférieure de l'intervalle élargi le plus court
c
A
−1
>
Bq·l
limite supérieure de l'intervalle élargi le plus court
c
A
quantiles de la loi normale centrée réduite pour les probabilités p (par exemple,
k
p
p11,/ou12 )
quantiles de la loi normale centrée réduite pour les probabilités q (par exemple,
k
q
q11,/ou12 )
m masse de résidu calciné du volume V mg
m masse du résidu de l'échantillon déposé sur la coupelle mg
r
−1
r taux de comptage du bruit de fond de la fenêtre alpha s
0α
−1
r taux de comptage du bruit de fond de la fenêtre bêta s
0β
−1
r taux de comptage global de l'échantillon de la fenêtre alpha s
gα
−1
r taux de comptage global de l'échantillon de la fenêtre bêta s
gβ
−1
r taux de comptage d'étalonnage de la source alpha de la fenêtre alpha s
sα
−1
r taux de comptage d'étalonnage de la source bêta de la fenêtre bêta s
sβ
−1
taux de comptage dans la fenêtre bêta lorsque la source d'étalonnage alpha est s
r
sα→β
mesurée
S surface de la coupelle mm
t durée de comptage du bruit de fond s
ISO/FDIS 9697:2026(fr)
t durée de comptage de l'échantillon s
g
t durée de comptage d'étalonnage des sources alpha et bêta s
s
−1
incertitude-type associée au résultat de mesure Bq·l
uc
A
incertitude-type de l'estimateur c , fonction d'une valeur vraie présumée c du
A A
uc
A
mesurande
incertitude relative de y
uy
rel
−1
U incertitude élargie calculée à partir de U = ku(c ), avec k = 1, 2 … Bq·l
A
volume de l'échantillon soumis à essai équivalent à la masse de solide sur la l
V
coupelle
V volume de l'échantillon d'eau l
t
ε efficacité de comptage pour l'étalon radioactif spécifié
−2
mg·mm
ρ masse surfacique du résidu de l'échantillon déposé sur la coupelle
s
facteur de correction du taux de rejet alpha-bêta, c'est-à-dire pourcentage de %
χ
comptage alpha passant dans la fenêtre bêta depuis la source d'étalonnage alpha
5 Principe
L'analyse de l'activité bêta globale est une méthode de contrôle destinée à garantir que l'activité volumique
de certains émetteurs bêta ne dépasse pas les niveaux de référence spécifiés. Ce type de détermination est
également appelé indice bêta global. L'analyse de l'activité bêta globale ne sera pas aussi exacte ni aussi
précise que l'analyse d'un radionucléide spécifique après des séparations radiochimiques. De plus, il ne s'agit
pas d'une détermination absolue de l'activité volumique de l'ensemble des radionucléides émetteurs bêta
d'un échantillon pour essai.
L'échantillon, prélevé, manipulé et conservé comme spécifié dans l'ISO 5667-1, l'ISO 5667-3 et l'ISO 5667-14,
est évaporé pratiquement à sec, converti sous forme de sulfate puis calciné à 350 °C. Une partie du résidu
est transférée sur une coupelle et l'activité bêta est mesurée à l'aide d'un compteur bêta (par exemple
un compteur proportionnel à circulation de gaz), étalonné par rapport à une source d'étalonnage bêta
40 90 90
appropriée, telle que le potassium-40 ( K) ou le strontium-90/yttrium-90 ( Sr + Y) à l'équilibre.
Si des mesurages alpha et bêta globaux sont requis simultanément sur le même échantillon d'eau, le mode
[13]
opératoire spécifié dans le présent document est très semblable à celui spécifié dans l'ISO 9696. Toutefois,
-2[12][15]
la masse surfacique de comptage doit être inférieure à 0,1 mg · mm .
L'Annexe A donne un exemple de critères de performance.
6 Réactifs chimiques et appareillage
6.1 Réactifs chimiques
Tous les réactifs doivent être de qualité analytique reconnue et ne doivent contenir aucune activité bêta
détectable.
NOTE Une méthode pour préparer des blancs de réactifs et pour contrôler l'absence de toute radioactivité bêta
inhérente ou de contamination est indiquée à l’Article 8.
ISO/FDIS 9697:2026(fr)
6.1.1 Eau ultrapure, de résistivité supérieure à 18,2 MΩ cm à 25 °C et dont le carbone organique total est
−1
inférieur à 1 μg∙l .
Sauf indication contraire, le terme “eau” désigne de l'eau ultrapure.
6.1.2 Source d'étalonnage, le choix de la source d'étalonnage bêta dépend de la connaissance du type de
contaminant radioactif susceptible d'être présent dans les eaux soumises à essai; celles avec du Sr et du
K sont couramment utilisées.
40 −1 −1
NOTE L'activité bêta du K dans le potassium naturel est de 27,9 Bq·g , c'est-à-dire 14,5 Bq·g dans le chlorure
[4]
de potassium .
−1
6.1.3 Acide nitrique, c(HNO ) = 8 mol·l .
−1 −1
6.1.4 Acide sulfurique, c(H SO ) = 18 mol·l , ρ = 1,84 g·ml , fraction massique w(H SO ) = 95 %.
2 4 2 4
6.1.5 Solvants organiques volatils, méthanol ou acétone.
6.1.6 Sulfate de calcium, CaSO .
6.1.7 Acétate de vinyle [(C H O ) ].
4 6 2 n
ATTENTION — Étant donné que les sels de calcium peuvent contenir des traces de Ra et/ou de
Pb, le contrôle de la présence de ces radionucléides doit être effectué.
6.2 Appareillage
Matériel courant de laboratoire et, en particulier, les éléments suivants:
6.2.1 Compteur bêta, de préférence du type compteur proportionnel à circulation de gaz, ou sinon
utilisant un détecteur de scintillation plastique ou un détecteur silicium de particules chargées.
Si un compteur proportionnel à circulation de gaz est utilisé, il est recommandé de choisir la fenêtre
électronique bêta ayant un taux de rejet bêta-alpha minimal et d'effectuer une correction pour le taux de rejet
239 241
alpha-bêta au moyen
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