prEN ISO 9697

SLOVENSKI STANDARD
01-januar-2026
Kakovost vode - Skupna beta aktivnost - Preskusna metoda robustnega vira
(ISO/DIS 9697:2025)
Water quality - Gross beta activity - Test method using thick source (ISO/DIS 9697:2025)
Wasserbeschaffenheit - Gesamt-Beta-Aktivität - Dickschichtverfahren (ISO/DIS
9697:2025)
Qualité de l'eau - Activité bêta globale - Méthode d'essai par source épaisse e (ISO/DIS
9697:2025)
Ta slovenski standard je istoveten z: prEN ISO 9697
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.

DRAFT
International
Standard
ISO/DIS 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
2025-11-28
source épaisse
Voting terminates on:
ICS: 13.060.60; 13.280 2026-02-20
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
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Reference number
ISO/DIS 9697:2025(en)
DRAFT
ISO/DIS 9697:2025(en)
International
Standard
ISO/DIS 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:
ICS: 13.060.60; 13.280
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2025
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
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Published in Switzerland Reference number
ISO/DIS 9697:2025(en)
ii
ISO/DIS 9697:2025(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and symbols . 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 . 8
9.1 Calculation of activity concentration .8
9.2 Standard uncertainty .9
9.3 Decision threshold .10
9.4 Limit of detection .10
9.5 Limits of the coverage intervals .10
9.5.1 Limits of the probabilistically symmetric coverage interval .10
9.5.2 The shortest coverage interval .11
10 Test report .11
Annex A (informative) Example of performance criteria .13
Bibliography . 14

iii
ISO/DIS 9697:2025(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.
This fifth edition cancels and replaces the fourth edition (ISO 9697:2018), which has been technically
revised.
The main changes are as follows:
— updates to the introduction to match the most recent template
— update of the normative references
— update of the update of the Symbols table for current formatting and additional symbols for the coverage
interval and uncertainty calculations
— update of the test report to conform to the current ISO standards
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/DIS 9697:2025(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 released from technological processes involving naturally occurring radioactive materials
(e.g. mining, mineral processing, oil, gas, and coal production, water treatment and the 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, Am,
60 137
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 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.
Compliance with these limits is assessed by measuring radioactivity in water samples and by comparing the
[5]
results obtained, with their associated uncertainties, as specified by ISO/IEC Guide 98-3 and 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 an effective dose
-1 −1
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 detectable
[4]
adverse health effects .
This document contains method(s) 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.
[8]
NOTE To include low-energy beta emitters in the gross beta analysis, ISO 11704 may be better suited. For
3 14 228 [9] [10] [11]
separate analysis of H, C and Ra, standards such as ISO 9698, ISO 13162 and ISO 22908, respectively, may
be better suited.
v
DRAFT International Standard ISO/DIS 9697:2025(en)
Water quality — Gross beta activity — Test method using
thick source
WARNING — Persons using this document should 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 tests conducted in accordance with this document 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. The method covers non-volatile radionuclides with maximum beta energies of approximately
3 228 210 14 35 241
0,3 MeV or higher. 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) are 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 with low amounts of total soluble
salts in the water. 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, it 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 (all parts), Determination of the characteristic limits (decision threshold, detection limit and limits of
the confidence interval) for measurements of ionizing radiation — Fundamentals and application
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
ISO/IEC Guide 98-3, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in
measurement (GUM:1995)
3 Terms, definitions and symbols
For the purposes of this document, the terms and definitions given in ISO 80000-10 and ISO 11929 series apply.

ISO/DIS 9697:2025(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
c beta activity concentration, without and with corrections Bq·l−1
A
*
Bq·l−1
decision threshold, without and with corrections
c
A
#
Bq·l−1
detection limit, without and with corrections
c
A

c possible or assumed true quantity values of the measurand Bq·l−1
A

Bq·l−1
lower limit of the probabilistically symmetric coverage interval
c
A

Bq·l−1
upper limit of the probabilistically symmetric coverage interval
c
A
<
Bq·l−1
lower limit of the shortest coverage interval
c
A
>
Bq·l−1
upper limit of the shortest coverage interval
c
A
Quantiles of the standardised normal distribution for the probabilities p (for instance p =
k
1−α , 1 - β or 1- γ /2)
p
Quantiles of the standardised normal distribution for the probabilities q (for instance q =
k
q
1−α , 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
r background count rate, from the alpha window s-1
0α
r background count rate, from the beta window s-1
0β
r sample gross count rate from the alpha window s-1
gα
r sample gross count rate from the beta window s-1
gβ
r calibration count rate of the alpha source from the alpha window s-1
sα
r calibration count rate of the beta source from the beta window s-1
sβ
r calibration count rate in the beta window when the alpha calibration source is measured s-1
sα→β
S surface area of the planchet mm2
t background counting time s
t sample counting time s
g
t calibration count time of the alpha and beta sources s
s
u(c ) standard uncertainty associated with the measurement result Bq·l−1
A
ISO/DIS 9697:2025(en)

standard uncertainty of the estimator c as a function of an assumed true value c of the
A A
 
uc
()
A
measurand
urel (y) relative uncertainty of y
U expanded uncertainty calculated from U = ku(c ), with k = 1, 2 … Bq·l−1
A
V volume of test sample equivalent to the mass of solid on the planchet l
Vt volume of the water sample l
ε counting efficiency for the specified radioactive standard
ρ source thickness, of the sample residue deposited on the planchet mg·mm-2
s
alpha-beta cross-talk, percentage of alpha count going into the beta window from the
χ
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
[12]
specified in this document is very similar to that of ISO 9696. However, the counting source thickness
2[13][14]
shall 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 recognised analytical grade and shall not contain any detectable beta activity.
NOTE A method for preparing reagent blanks to check for the absence of any inherent beta radioactivity or
contamination is given in Clause 7.
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 activit
...