SIST EN ISO 13161:2021

SLOVENSKI STANDARD
oSIST prEN ISO 13161:2019
01-marec-2019
Kakovost vode - Merjenje koncentracije aktivnosti polonija Po-210 v vodi z alfa
spektrometrijo (ISO/DIS 13161:2019)
Water quality - Measurement of polonium 210 activity concentration in water by alpha
spectrometry (ISO/DIS 13161:2019)
Wasserbeschaffenheit - Bestimmung der Aktivitätskonzentration von Polonium-210 in
Wasser mittels Alphaspektrometrie (ISO/DIS 13161:2019)
Qualité de l'eau - Mesurage de l'activité du polonium 210 dans l'eau par spectrométrie
alpha (ISO/DIS 13161:2019)
Ta slovenski standard je istoveten z: prEN ISO 13161 rev
ICS:
13.060.60 Preiskava fizikalnih lastnosti Examination of physical
vode properties of water
17.240 Merjenje sevanja Radiation measurements
oSIST prEN ISO 13161:2019 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 13161:2019

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oSIST prEN ISO 13161:2019
DRAFT INTERNATIONAL STANDARD
ISO/DIS 13161
ISO/TC 147/SC 3 Secretariat: AFNOR
Voting begins on: Voting terminates on:
2019-02-06 2019-05-01
Water quality — Polonium 210 — Test method using alpha
spectrometry
Qualité de l'eau — Polonium 210 — Méthode par spectrométrie alpha
ICS: 13.060.60; 17.240
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 13161:2019(E)
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 SUPPORTING DOCUMENTATION. ISO 2019

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COPYRIGHT PROTECTED DOCUMENT
© ISO 2019
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
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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
4.1 General . 3
4.2 Treatment . 3
4.2.1 Treatment for a deposition on a disc . 3
4.2.2 Treatment for a precipitation on a filter. 4
4.3 Principle of alpha spectrometry . 4
5 Reagents and equipment . 4
5.1 Reagents. 4
5.2 Preparation material and treatment . 5
5.3 Alpha spectrometry measuring equipment . 5
6 Sampling and samples . 5
7 Chemical treatment and deposit process . 6
7.1 General . 6
7.2 Chemical treatment . 6
7.2.1 Autodeposition of polonium on a disc. 6
7.2.2 Microprecipitation on a filter . 7
8 Measurement by alpha spectrometry . 8
8.1 General . 8
8.2 Quality control . 8
8.3 Measurement . 8
9 Expression of results . 8
9.1 General . 8
9.2 Total yield . 9
210
9.3 Activity concentration of Po in the sample . 9
9.4 Combined uncertainties .10
9.5 Decision threshold .10
9.6 Detection limit .11
9.7 Confidence limits.11
10 Test report .11
Annex A (informative) Cell deposit examples .13
Annex B (informative) Spectrum examples .15
Bibliography .17
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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 on 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 the following
URL: www .iso .org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 147, Water quality, Subcommittee SC 3,
Radiological methods.
This second edition cancels and replaces the first edition (ISO 13161:2011), which has been technically
revised. The main changes compared to the previous edition are as follows:
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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:.
— Natural radionuclides, including 40K, 3H, 14C, and those originating from the thorium and uranium
decay series, in particular 226Ra, 228Ra, 234U, 238U, and 210Pb, 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 fertilizer production and use);
— Human-made radionuclides, such as transuranium elements (americium, plutonium, neptunium,
curium), 3H, 14C, 90Sr, 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 the 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 the
[2]
environment and water bodies. Water Drinking water are monitored for their radioactivity content 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 regulation 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
using measurement results with their associated uncertainties as specified by ISO/IEC Guide 98-3 and
[4]
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
guidance level in drinking water is 0,1 Bq l-1 for polonium 210 activity concentration.
NOTE 1 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.
[5]
In the event of a nuclear emergency, the WHO Codex Guideline Levels mentioned that the activity
concentration might be greater.
NOTE 2 The Codex guidelines levels (GLs) apply to radionuclides contained in foods destined for human
consumption and traded internationally, which have been contaminated following a nuclear or radiological
emergency. These GLs apply to food after reconstitution or as prepared for consumption, i.e., not to dried or
concentrated foods, and are based on an intervention exemption level of 1 mSv in a year for members of the
[5]
public (infant and adult).
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]
or for an emergency situation.
Usually, the test methods can be adjusted to measure the activity concentration of the radionuclide(s)
in either wastewaters before storage or in liquid effluents before being discharged to the environment.
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The test results will enable the plant/installation operator to verify that, before their discharge,
wastewaters/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 wastewaters and liquid effluents with specific modifications that
could increase the overall uncertainty, detection limit, and threshold.
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 polonium 210 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.
Polonium 210 is a natural alpha-emitting radionuclide with a half-life of 138 d. It appears in the natural
chain of uranium 238 (see Figure 1). It is a long-life decay product of radon 222 (in the frame of Figure 1)
[8] [12]
through lead 210 (see References to ).
206
NOTE Pb is stable.
Figure 1 — Uranium 238 and its decay products
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DRAFT INTERNATIONAL STANDARD ISO/DIS 13161:2019(E)
Water quality — Polonium 210 — Test method using alpha
spectrometry
WARNING — Persons using this document should be familiar with normal laboratory practices.
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 essential that tests conducted according to this test method be carried out
by suitably trained staff.
1 Scope
210
This document specifies a method for the measurement of Po in all types of waters by alpha
spectrometry.
The method is applicable to test samples of supply/drinking water, rainwater, surface and ground water,
marine water, as well as cooling water, industrial water, domestic, and industrial wastewater after
proper sampling and handling, and test sample preparation. A filtration of the test sample is necessary.
The detection limit depends on the sample volume, the instrument used, the background count rate, the
detection efficiency and the chemical yield. The method described in this document, using currently
-1
available alpha spectrometry apparatus, has a detection limit of approximately 5 mBq.l , which is
-1
lower than the WHO criteria for safe consumption of drinking water (100 mBq·l ). This value can be
achieved with a counting time of 24 hours for a sample volume of 500 ml.
The method described in this document is applicable in the event of an emergency situation.
210
The analysis of Po adsorbed to suspended matter is not covered by this method.
It is the user’s responsibility to ensure the validity of this test method for the water samples tested.
If suspended material has to be removed or analysed, filtration at 0,45 μm is recommended. The
analysis of the insoluble fraction requires a mineralization step that is not covered by this document
[13]
(see NF M 60-790-4 ). In this case, the measurement is made on the different phases obtained. The
final activity is the sum of all the measured activity concentrations.
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 5667-10, Water quality — Sampling — Part 10: Guidance on sampling of waste waters
ISO 11929, 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
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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, symbols and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 80000-10 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http: //www .electropedia .org/
— ISO Online browsing platform: available at http: //www .iso .org/obp
3.1.1
certified reference solution
solution of known concentration traceable to primary or secondary certified reference solution
standards of radioactivity
3.1.2
tracer solution
208 209
usually a secondary standard or reference material, such as Po or Po, employed to determine the
chemical yield of the analysis
3.1.3
quality control standard
radioactive source used to demonstrate that the measurement equipment employed performs within
defined limits
Note 1 to entry: Quality control is usually carried out by the regular measurement of a suitable radioactive source
[14] [15] [16]
in accordance with ISO 7870-1 , ISO 7870-2, and ISO 7870-4.
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.
A activity of the tracer added Bq
210 −1
c activity concentration of Po Bq l
A
−1
* Bq l
c decision threshold
A
−1
# Bq l
c detection limit
A
−1
 Bq l
cc,
lower and upper limits of the confidence interval
AA
R chemical yield 1
c
R total yield 1
T
210 −1
r background count rate in the Po region of interest s
0
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−1
r background count rate in the tracer region of interest s
0T
210 −1
r gross count rate of the sample in the Po region of interest s
g
−1
r gross count rate in the tracer region of interest s
T
t background counting time s
0
t sample counting time s
g
−1
U expanded uncertainty calculated by U = k ⋅□u(c ) with k = 1, 2 . Bq l
A
−1
u(c ) standard uncertainty associated with the initial measurement result Bq l
A
V volume of the test sample aliquot l
ε counting efficiency 1
4 Principle
4.1 General
210
There are different techniques to measure Po activity concentration in water: alpha spectrometry,
liquid scintillation counting, and alpha proportional counting. This document describes the alpha
spectrometry technique.
After sampling, the test sample undergoes a treatment which leads to an extremely thin deposit of the
polonium on a metal disc or on a filter, for measurement by alpha spectrometry.
210 [17]
Po has a half-life of 138,376 d ± 0,002 d (see Reference ).
The sample shall be analysed as soon as possible to evaluate an activity concentration on the sampling
date. If the time elapsed between sampling and measurement is long, the activity concentration
210 210
measured requires correction and it is then necessary to know the Pb and Bi activity
210
concentrations of the sample to adjust the Po activity concentration on the sampling date.
4.2 Treatment
4.2.1 Treatment for a deposition on a disc
The main steps of the sample treatment are:
— filtration if necessary;
— acidification with concentrated hydrochloric acid (or nitric acid) and addition of a polonium tracer
208 209
( Po or Po) solution;
208 209
NOTE The polonium isotopes Po (5,11 MeV alpha emission) or Po (4,88 MeV alpha emission) can be
210
used as tracers since interference with Po (5,31 MeV alpha emission) is minimal for sources displaying good
209 208
resolution (< 50 keV FWHM); Po is preferred, but Po is acceptable.
— addition of a reducing agent (e.g. ascorbic acid);
— spontaneous deposition of a thin layer on to a metal disc.
The activity concentration measurement as well as the determination of the total yield is carried out by
alpha spectrometry.
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4.2.2 Treatment for a precipitation on a filter
[18][19]
The main steps of the sample treatment are:
— filtration;
208 209
— acidification with concentrated hydrochloric acid and addition of a polonium tracer ( Po or Po)
solution;
208 209
NOTE The polonium isotopes Po (5,11 MeV alpha emission) or Po (4,88 MeV alpha emission) can be
210
used as tracers since interference with Po (5,31 MeV alpha emission) is minimal for sources displaying good
209 208
resolution (< 50 keV FWHM); Po is preferred, but Po is acceptable.
— evaporate to dryness;
— dissolve with 10 ml of 1 mol/l HCl;
— filter the solution;
— add a co-precipitation agent (e.g. 50 μg of copper as copper chloride);
— micro-precipitate polonium with sulfide;
— filter on a filter.
The activity concentration measurement as well as the determination of the total yield is carried out by
alpha spectrometry.
4.3 Principle of alpha spectrometry
The thin layer deposited on the metal disc or on a filter allows the detection of alpha particles. The
interaction of alpha particles and detector results in a change in (bias) current that is proportional to
the energy of the particles.
The electronic pulses generated by the detector are amplified, and displayed as an energy spectrum
using an analogue-digital converter, multiple channel analyser, and computer processing. The spectrum
display enables the radionuclides present in the source to be identified and integration of counts enables
the determination of activity concentration of the test sample, taking into account the background
counting rates and/or the blank test and the total yield.
A blank test should be carried out with the same reagents replacing the water sample by water
complying with ISO 3696, grade 3 previously used for the preparation of the reagents without tracer.
To ensure an acceptable performance of the detector system, a quality control standard shall be
measured.
210
The chemical yield of Po measurement is determined by adding a radioactive tracer. The total yield
is a product of the chemical yield and the detection efficiency.
5 Reagents and equipment
5.1 Reagents
During chemical treatment and cleaning of the metal disc, use only reagents of recognized analytical
210
grade. Use only reagents with no measurable Po concentration.
5.1.1 Water, complying with ISO 3696, grade 3.
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5.1.2 Tracer solution.
208 209
Po (T = 1 058,5 d ± 0,7 d) or Po (T = 37 300 d ± 1 800 d) tracer solution of known activity;
1/2 1/2
210 [20][21]
the spike is adjusted to the Po activity concentration expected in the test sample (References ).
208
When Po is used, its decay shall be taken into account in accordance with the information given on
the calibration certificate.
209
NOTE The half-life of Po and its associated uncertainty commonly used was subjected to a recent
[22]
investigation that suggests an uncertainty of ± 25 % instead of 4,8 % (Reference ).
5
...