SIST EN ISO 13162:2021

SLOVENSKI STANDARD
oSIST prEN ISO 13162:2020
01-marec-2020
Kakovost vode - Ogljik C-14 - Preskusna metoda s štetjem s tekočinskim
scintilatorjem (ISO/DIS 13162:2020)
Water quality - Carbon 14 - Test method using liquid scintillation counting (ISO/DIS
13162:2020)
Wasserbeschaffenheit - Kohlenstoff-14 - Verfahren mit dem Flüssigszintillationszähler
(ISO/DIS 13162:2020)
Qualité de l’eau - Carbone 14 - Méthode d’essai par comptage des scintillations en
milieu liquide (ISO/DIS 13162:2020)
Ta slovenski standard je istoveten z: prEN ISO 13162
ICS:
13.060.60 Preiskava fizikalnih lastnosti Examination of physical
vode properties of water
17.240 Merjenje sevanja Radiation measurements
oSIST prEN ISO 13162:2020 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 13162:2020

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oSIST prEN ISO 13162:2020
DRAFT INTERNATIONAL STANDARD
ISO/DIS 13162
ISO/TC 147/SC 3 Secretariat: AFNOR
Voting begins on: Voting terminates on:
2020-01-28 2020-04-21
Water quality — Carbon 14 — Test method using liquid
scintillation counting
ICS: 17.240; 13.060.60
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 13162:2020(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 2020

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oSIST prEN ISO 13162:2020
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COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
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 Symbols, definitions, units, and abbreviations . 2
4 Principle . 3
5 Sampling and storage . 3
5.1 Sampling . 3
5.2 Sample storage . 3
6 Reagents and equipment . 4
6.1 Reagents. 4
6.1.1 Reference water for the blank . 4
6.1.2 Calibration source solution . 4
6.1.3 Scintillation solution. 4
6.1.4 Quenching agent. 5
6.2 Equipment . 5
7 Procedure. 5
7.1 Sample preparation . 5
7.2 Preparation of the counting vial . 5
7.3 Counting procedure . 5
7.4 Calibration and verification . 5
7.5 Measurement conditions . . 6
8 Expression of results . 7
8.1 General . 7
8.2 Calculation of activity concentration without sample preparation . 7
8.3 Calculation of activity concentration with sample preparation . 7
8.4 Decision threshold . 8
8.5 Detection limit . 8
8.6 Limits of the coverage intervals . 9
8.6.1 Limits of the probabilistically symmetric coverage interval. 9
8.6.2 Limits of the shortest coverage interval . 9
8.7 Calculations using the activity per mass .10
9 Test report .10
Annex A (informative) Numerical applications .12
Annex B (informative) Internal standard method .14
Annex C (informative) Extraction of total carbon by precipitation of calcium carbonate .16
Annex D (informative) Extraction of total carbon: absorption counting .19
Bibliography .22
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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,
Radioactivity measurements.
This second edition cancels and replaces the first edition (ISO 13162:2011), [Clauses 1, 2, 3, 4, 6 /
subclause 7.1] of which have been technically revised.
The main changes compared to the previous edition are as follows:
— Introduction developed;
— Scope updated;
— References updated;
— Sample preparation revised.
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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:
40 3 14
— natural radionuclides, including K, H, C, and those originating from the thorium and uranium
226 228 234 238 210 210
decay series, in particular Ra, Ra, U, U, Po and Pb can be found in water for
natural reasons (e.g. desorption from the soil and washoff by rain water) or can be released from
technological processes involving naturally occurring radioactive materials (e.g. the mining and
processing of mineral sands or phosphate fertilizers production and use);
— human-made radionuclides such as transuranium elements (americium, plutonium, neptunium,
3 14 90
curium), H, C, Sr, and gamma emitting radionuclides can also be found in natural waters.
Small quantities of these radionuclides are discharged from nuclear fuel cycle facilities into the
environment as a result of authorized routine releases. Some of these radionuclides used for
medical and industrial applications are also released into the environment after use. Anthropogenic
radionuclides are also found in waters as a result of past fallout contaminations resulting from
the explosion in the atmosphere of nuclear devices and accidents such as those that occurred in
Chernobyl and Fukushima.
Radionuclide activity concentration in water bodies can vary according to local geological
characteristics and climatic conditions and can be locally and temporally enhanced by releases from
[1]
nuclear installation during planned, existing, and emergency exposure situations. Drinking-water
may thus contain radionuclides at activity concentrations which could present a risk to human health.
The radionuclides present in liquid effluents are usually controlled before being discharged into
[2]
the environment and water bodies. Drinking waters are monitored for their radioactivity as
[3]
recommended by the World Health Organization (WHO) so that proper actions can be taken to ensure
that there is no adverse health effect to the public. Following these international recommendations,
national regulations usually specify radionuclide authorized concentration limits for liquid effluent
discharged to the environment and radionuclide guidance levels for waterbodies 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
-1 14
guidelines for guidance level in drinking water is 100 Bq l for C 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 .
[6]
In the event of a nuclear emergency, the WHO Codex Guideline Levels mentioned that the activity
-1 14
concentration might not be greater than 10000 Bq l for C in foods other than for infant foods.
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).
14
An International Standard on a test method of C 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.
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oSIST prEN ISO 13162:2020
DRAFT INTERNATIONAL STANDARD ISO/DIS 13162:2020(E)
Water quality — Carbon 14 — Test method using liquid
scintillation counting
WARNING — Persons using this document should be familiar with normal laboratory practice.
This document does not purport to address all of the safety problems, if any, associated with its
use. It is the responsibility of the user to establish appropriate safety and health practices.
IMPORTANT — It is absolutely essential that tests conducted according to this document be
carried out by suitably trained staff.
1 Scope
14
This document specifies a method for the measurement of C activity concentration in all types of
water samples by liquid scintillation counting either directly on the test sample or following a chemical
separation.
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.
The detection limit depends on the sample volume, the instrument used, the sample counting time, the
background count rate, the detection efficiency and the chemical recovery. The method described in
this document, using currently available liquid scintillation counters and suitable technical conditions
−1
has a detection limit as low as 1 Bq l , which is lower than the WHO criteria for safe consumption of
-1 14 6 -1
drinking water (100 Bq·l ). C activity concentrations can be measured up to 10 Bq l without any
sample dilution.
It is the user’s responsibility to ensure the validity of this test method for the water samples tested.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 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 coverage interval) for measurements of ionizing radiation — Fundamentals and
application —Part 1: Elementary applications
ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
ISO 19361, Measurement of radioactivity — Determination of beta emitters activities — Test method using
liquid scintillation counting
ISO 80000-10, Quantities and units — Part 10: Atomic and nuclear physics
ISO/IEC Guide 98-3:2008, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in
me a s ur ement (GUM: 1995)
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ISO/IEC Guide 99:2007, International vocabulary of metrology — Basic and general concepts and
associated terms (VIM)
3 Symbols, definitions, units, and abbreviations
For the purposes of this document, the definitions, symbols and abbreviations defined
in ISO/IEC Guide 99:2007, ISO/IEC Guide 98-3:2008, 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 https:// www .iso .org/ obp
β Maximum energy for the beta emission, in keV keV
max
V
Volume of laboratory sample, in litre l
m
Mass of laboratory sample, in kilogram kg
-1
ρ
Density of the sample, in kilogram per litre kg l
-1
c Activity concentration, in becquerel per litre Bq l
A
-1
a
Activity per unit of mass, in becquerel per kilogram Bq kg
A Activity of the calibration source, in becquerel Bq
n Number of counting -
t Background counting time, in second s
0
t Sample counting time, in second s
g
t Calibration counting time, in second s
s
-1
r Background count rate, per second s
0
-1
r Test sample count rate, per second s
g
-1
r Calibration count rate, per second s
s
ε
Detection efficiency -
f Quench factor -
q
ε Chemical recovery -
p
m Mass of total carbon in the sample, in kilogram kg
TC
m Mass of carbon in the precipitate, in kilogram kg
PC
m Mass of carbon in the carrier, in kilogram kg
CC
m Mass of sample carbon in the precipitate, in kilogram kg
SC
-1
Standard uncertainty associated with the measurement result; in becquerel per litre Bq l
uc()
A
-1
Bq l
U Expanded uncertainty, calculated by Uk=⋅uc with k = 1, 2,…, in becquerel per litre
()
A
-1
*
Decision threshold, in becquerel per litre Bq l
c
A
-1
#
Detection limit, in becquerel per litre Bq l
c
A
-1
Lower and upper limits of the probabilistically symmetric coverage interval, in bec- Bq l

C ,C
AA
querel per litre
-1

Lower and upper limits of the shortest coverage interval, in becquerel per litre Bq l
cc,
AA
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4 Principle
14
The method described is for measurement of C in water samples by direct liquid scintillation counting.
The general principles of this method are described in ISO 19361.
This direct determination is applicable to the analysis of water samples that can produce a homogeneous
mixture between the test portion and a suitable scintillation cocktail.
The direct LSC method does not apply to waters containing micelles or large organic molecules (e.g.
lipids, fulvic acid, humic acid, etc.) that do not form homogeneous mixtures with scintillation cocktails.
In these cases, there is a risk that the beta radiation is attenuated by the micelles. This will reduce
the counting efficiency of the system and hence the results may be underestimated. For these samples,
14
the determination of C requires additional chemical processing (such as chemical oxidation or
combustion). Examples of methods of chemical preparation are described in Annexes C and D.
The choice of the analytical procedure (either with or without chemical preparation of the water sample
[17] [18]
prior to determination), depends on the aim of the measurement and the sample characteristics
[19] [20]
.
14
A prerequisite for the direct determination of C in a water sample is the absence of, or a negligible
90
contribution from, other beta-emitting radionuclides, such as Sr and Ra isotopes. When the
radionuclide content of the sample is unknown, the method specified in this document only provides a
14
C equivalent activity for the sample.
To determine the background count rate, a blank sample is prepared in the same way as the test portion.
The blank sample is prepared using a reference water of the lowest activity available, also sometimes
called “dead water”.
14
To determine the detection efficiency, it is necessary to measure a water sample having a known C
activity under conditions that are identical to those used for the test sample. This water shall be a
14
dilution of this mixture produced with the reference water, or a water with a traceable C activity
usable without dilution.
Where chemical quenching may affect the measurement results, it is necessary to correct the counting
data using a quench curve (see 7.4).
5 Sampling and storage
5.1 Sampling
Conditions of sampling and handling shall conform to ISO 5667 part 1, 3 and 10. Guidance is given for
the different types of water in references [8] to[15].
2- -
The samples shall not be acidified to avoid the destruction of the carbonic equilibrium (CO , HCO ,
3 3
H CO ), as specified in ISO 5667-3. Basification of the sample is recommended, for example to between
2 3
pH 8 and 9.
It is important that the laboratory receives a representative sample, unmodified during transport or
storage and in an undamaged container. It is recommended that a glass container filled to the maximum
14
is used to minimize C exchange with atmospheric CO .
2
For low level activity measurements, it is important to minimize any contact between sample and
atmosphere during the sampling.
5.2 Sample storage
If required, the sample shall be stored in accordance with ISO 5667-3 for carbon dioxide. If the storage
duration exceeds that specified in ISO 5667-3, it is advisable to store the samples in glass containers.
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6 Reagents and equipment
During the analysis, unless otherwise stated, use only reagents of recognized analytical grade.
6.1 Reagents
6.1.1 Reference water for the blank
The reference water for the blank should be as free as possible of chemical or radioactive impurities,
14
although it may have a low C activity concentration, at the time the samples are measured.
For example, obtain water with a 14C activity concentration as low as possible, e.g. (deep)
subterranean water. Distill the water. Keep the distillate in a well-sealed borosilicate glass bottle in
the dark at a temperature as constant as possible; this reference water shall be kept physically remote
from any
14C-containing material (see next paragraph). Determine (see final paragraph) the 14C activity
concentration of this water, in becquerel per litre, and note the date of this determination.
It is advisable to keep an adequate quantity of reference water in stock and to draw off small working
14
volumes from it for immediate use, as required. Contamination with C (e.g. from CO in the air) or
2
other radioactive species should be avoided.
−1
For measurement of activity concentrations close to 1 Bq l , water with a very low activity concentration
is necessary as reference water.
6.1.2 Calibration source solution
In order to avoid cross-contamination, prepare the calibration source solution in a suitable location
14
which is well removed from the area where the C analyses are to be carried out. Transfer a known
14
amount of C aqueous standard solution into a volumetric flask (e.g. of capacity 100 ml). Make up to
the mark with blank reference water and mix well. The calibration source solution must have sufficient
14
C activity such that, when used to prepare counting sources, a suitable count rate to reach the
14
required measurement uncertainty is obtained. Calculate the C activity concentration of the resulting
calibration source solution, in becquerel per litre. Note the date at which the standard solution was
made up, to monitor the ageing of the solution.
It is recommended to select the standard source container size so as to minimize the volume of air
14
above the solution and therefore minimize the exchange of C with the atmosphere at each opening of
the container.
6.1.3 Scintillation solution
The scintillation cocktail is chosen according to the characteristics of the test sample to be analysed
[21][22]
(e.g. precipitate or alkaline) and according to the properties of
...