Water quality - Gamma-ray emitting radionuclides - Test method using high resolution gamma-ray spectrometry (ISO 10703:2021)

Wasserbeschaffenheit - Gammastrahlung emittierende Radionukliden - Verfahren mittels Gammaspektrometrie (ISO 10703:2021)

Dieses Dokument legt ein Verfahren zur physikalischen Vor- und Aufbereitung von Wasserproben und zur Bestimmung der Aktivitätskonzentration verschiedener Gammastrahlen mit Energien von 40 keV < E < 2 MeV emittierender Radionuklide in Wasserproben mittels Gammaspektrometrie nach dem in ISO 20042 [9] beschriebenen generischen Prüfverfahren fest.
ANMERKUNG   Auch die Bestimmung der Aktivitätskonzentration von Radionukliden, die Gammastrahlen mit Energien unter 40 keV und über 2 MeV emittieren, ist im Anwendungsbereich dieses Dokuments möglich, sofern sowohl die Kalibrierung des Messsystems als auch die Abschirmung an diesen Zweck angepasst ist.
Dieses Dokument ist nur auf homogene Proben anwendbar. Die untere Grenze, die so gemessen werden kann, d. h. ohne Verdünnung oder Konzentrierung der Probe und ohne Anti-Compton-Spektrometer beträgt etwa 5·10−2 Bq/l für eg137Cs. Die obere Grenze der Aktivität korrespondiert mit einer Totzeit von 5 %.
Abhängig von verschiedenen Faktoren wie der Energie der Gammastrahlen und der Emissions-wahrscheinlichkeit, der Größe und Geometrie der Probe und des Detektors, der Abschirmung, der Messdauer und anderer Versuchsparameter, wird die Probe durch Eindampfen konzentriert, wenn Aktivitäten unter 5·10−2 Bq/l gemessen werden müssen. Flüchtige Radionuklide (z. B. Radon und Radioiod) können während der Vorbereitung der Quelle verloren gehen.
Wenn die Totzeit mehr als 5 % beträgt, ist die Probe entweder verdünnt worden, oder ein Aliquot der Probe ist verwendet worden, oder der Abstand zwischen Quelle und Detektor ist vergrößert worden, oder eine Korrektur der Pile-Up-Effekte ist vorgenommen worden.

Qualité de l'eau - Radionucléides émetteurs gamma - Méthode d’essai par spectrométrie gamma à haute résolution (ISO 10703:2021)

Kakovost vode - Radionuklidi, ki sevajo žarke gama - Preskusna metoda z gama spektrometrijo visoke ločljivosti (ISO/FDIS 10703:2021)

General Information

Status
Published
Technical Committee
Current Stage
6060 - Definitive text made available (DAV) - Publishing
Due Date
07-Jul-2021
Completion Date
07-Jul-2021

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SLOVENSKI STANDARD
oSIST prEN ISO 10703:2020
01-april-2020
Kakovost vode - Radionuklidi, ki sevajo žarke gama - Preskusna metoda z gama
spektrometrijo (ISO/DIS 10703:2020)
Water quality - Gamma-ray emitting radionuclides - Test method using gamma-ray
spectrometry (ISO/DIS 10703:2020)

Wasserbeschaffenheit - Bestimmung der Aktivitätskonzentration von Radionukliden -

Verfahren mittels hochauflösender Gammaspektrometrie (ISO/DIS 10703:2020)

Qualité de l'eau - Radionucléides émetteurs gamma - Méthode d'essai par spectrométrie

gamma (ISO/DIS 10703:2020)
Ta slovenski standard je istoveten z: prEN ISO 10703
ICS:
13.060.60 Preiskava fizikalnih lastnosti Examination of physical
vode properties of water
17.240 Merjenje sevanja Radiation measurements
oSIST prEN ISO 10703:2020 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 10703:2020
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oSIST prEN ISO 10703:2020
DRAFT INTERNATIONAL STANDARD
ISO/DIS 10703
ISO/TC 147/SC 3 Secretariat: AFNOR
Voting begins on: Voting terminates on:
2020-02-24 2020-05-18
Water quality — Gamma-ray emitting radionuclides — Text
method using gamma-ray spectrometry

Qualité de l'eau — Radionucléides émetteurs gamma — Méthode d'essai par spectrométrie gamma

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
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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 10703:2020(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 10703:2020
ISO/DIS 10703:2020(E)
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

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.
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ii © ISO 2020 – All rights reserved
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Contents Page

Foreword ..........................................................................................................................................................................................................................................v

Introduction ................................................................................................................................................................................................................................vi

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 2

4 Symbols and units ............................................................................................................................................................................................... 3

5 Principle ........................................................................................................................................................................................................................ 4

6 Reference sources ............................................................................................................................................................................................... 4

7 Reagents ........................................................................................................................................................................................................................ 4

8 Gamma spectrometry equipment ....................................................................................................................................................... 5

8.1 General ........................................................................................................................................................................................................... 5

8.2 Detector types .......................................................................................................................................................................................... 5

8.3 High voltage power supply ........................................................................................................................................................... 5

8.4 Preamplifier ............................................................................................................................................................................................... 5

8.5 Cryostat, capable of keeping the detector close to the temperature of liquid nitrogen........... 5

8.6 Shielding ....................................................................................................................................................................................................... 6

8.7 Main amplifier ......................................................................................................................................................................................... 6

8.8 Multichannel analyser or multichannel buffer ............................................................................................................ 6

8.9 Computer, including peripherical devices and software .................................................................................... 6

9 Nuclear decay data ............................................................................................................................................................................................. 7

10 Sampling ........................................................................................................................................................................................................................ 7

11 Procedure..................................................................................................................................................................................................................... 8

11.1 Sample preparation ............................................................................................................................................................................ 8

11.1.1 General...................................................................................................................................................................................... 8

11.1.2 Direct measurement without preparation ................................................................................................ 8

11.1.3 Evaporation without iodine retention........................................................................................................... 8

11.1.4 Evaporation with iodine retention ................................................................................................................... 8

11.2 Calibration .................................................................................................................................................................................................. 8

12 Expression of results ........................................................................................................................................................................................ 9

12.1 Calculation of the activity concentration .......................................................................................................................... 9

12.1.1 General...................................................................................................................................................................................... 9

12.1.2 Decay corrections .........................................................................................................................................................10

12.1.3 Summation effects or coincidence losses corrections ..................................................................10

12.2 Standard uncertainty ......................................................................................................................................................................11

12.3 Decision threshold ............................................................................................................................................................................11

12.4 Detection limit ......................................................................................................................................................................................11

12.5 Limits of the coverage intervals ............................................................................................................................................12

12.5.1 Limits of the probabilistically symmetric coverage interval...................................................12

12.5.2 The shortest coverage interval .........................................................................................................................12

12.6 Corrections for contributions from other radionuclides and background ......................................12

12.6.1 General...................................................................................................................................................................................12

12.6.2 Contribution from other radionuclides .....................................................................................................13

12.6.3 Contribution from background ........................................................................................................................14

13 Test report ................................................................................................................................................................................................................14

Annex A (informative) Example of a carrier solution which can be added to the water

sample when waste water from a nuclear power plant is investigated....................................................16

Annex B (informative) Calculation of the activity concentration from a gamma spectrum

using a linear background subtraction (undisturbed peak) ...............................................................................17

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Bibliography .............................................................................................................................................................................................................................19

iv © ISO 2020 – All rights reserved
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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 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 third edition cancels and replaces the second edition (ISO 10703:2007), which has been technically

revised.
© ISO 2020 – All rights reserved v
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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 . Water bodies and drinking waters 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 regulations usually specify radionuclide authorized concentration limits for liquid effluent

discharged to the environment and radionuclide guidance levels for water bodies and drinking waters

for planned, existing and emergency exposure situations. Compliance with these limits can be assessed

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

guidelines for guidance level in drinking water is x Bq·l for x 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

−1 −1

concentration might not be greater than X Bq·l for infant food and X Bq·l for food other than infant

food, including organically bound tritium.

NOTE 2 The Codex guidelines levels (GLs) apply to radionuclides contained in food 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 food, and are based on an intervention exemption level of 1 mSv in a year for members of the public

[5]
(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 .
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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 discharge to the environment. 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 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 may be used for water samples after proper sampling, sample handling, and test

sample preparation (see the relevant part of the ISO 5667 series).

This document has been developed to answer the need of test laboratories carrying out these

measurements, that are sometimes required by national authorities, as they 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 10703:2020
DRAFT INTERNATIONAL STANDARD ISO/DIS 10703:2020(E)
Water quality — Gamma-ray emitting radionuclides — Text
method using gamma-ray spectrometry

WARNING — Persons using this document should be familiar with normal laboratory practice.

This International Standard 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 and to ensure compliance with any national regulatory conditions.

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 method for the physical pre-treatment and conditioning of water samples

and the determination of the activity concentration of various radionuclides emitting gamma rays

with energies 40 keV < E < 2 MeV, by gamma-ray spectrometry according to the generic test method

[9]
described in ISO 20042 .

NOTE The determination of the activity concentration of radionuclides emitting gamma rays with energy

below 40 keV and above 2 MeV is also possible within the scope of this document, provided both the calibration of

the measuring system and the shielding are adapted to this purpose.

This document is only applicable to homogeneous samples. The lowest limit that can be measured as

such, i.e. without dilution or concentration of the sample or anti Compton device is about 5.10 Bq/l for

137
eg Cs. The upper limit of the activity corresponds to a dead time of 5%.

Depending on different factors, such as the energy of the gamma rays and the emission probability per

nuclear disintegration, the size and geometry of the sample and the detector, the shielding, the counting

time and other experimental parameters, the sample is concentrated by evaporation when activities

below 5.10 Bq/l have to be measured. However, volatile radionuclides (e.g. radon and radioiodine) can

be lost during the source preparation.

When the dead time is higher than 5%, the sample is either diluted or an aliquot of the sample is taken

or the source to detector distance is increased or a correction for pile-up effects is applied.

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 80000-10, Quantities and units — Part 10: Atomic and nuclear physics

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 20042:2019, Measurement of radioactivity — Gamma-ray emitting radionuclides — Generic test

method using gamma-ray spectrometry
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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 11929-3, Determination of the characteristic limits (decision threshold, detection limit and limits of

the coverage interval) for measurements of ionizing radiation — Fundamentals and application — Part 3:

Applications to unfolding methods

ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories

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)
3 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:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org
3.1
blank sample

container of an identical composition to the one used for the water test sample filled with radon free

demineralized water
3.2
dead time

time during spectrum acquisition (real time) during which pulses are not recorded or processed

Note 1 to entry: Dead time is given by real time minus live time.
Note 2 to entry: The time is given in seconds.
3.3
dead time correction

correction to be applied to the observed number of pulses in order to take into account the number of

pulses lost during the dead time
3.4
decay constant

quotient of dP by dt, where dP is the probability of a given

nucleus undergoing a spontaneous nuclear transition from that energy state in the time interval dt

dP 1 dN
λ== −
dtN dt
where N is the number of nuclei of concern existing at time t
3.5
efficiency

under stated conditions of detection, the ratio of the number of detected gamma-photons to the number

of gamma-photons of the same type emitted by the radiation source in the same time interval

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3.6
energy resolution

measure, at a given energy, of the smallest difference between the energy of two gamma rays which can

be distinguished by the apparatus used for gamma-ray spectrometry
3.7
full energy peak

peak of spectral response curve corresponding to the total absorption of the photon energy in the

sensitive detector volume by the photoelectric effect or by consecutive photon interactions of pair

production (only for photon energy > 1 022 keV), Compton scattering and photoelectric absorption

3.8
gamma cascade

two or more different gamma-photons emitted successively within the resolution time, from one

nucleus when it de-excites through one or more intermediate energy levels
3.9
gamma radiation

electromagnetic radiation emitted in the process of nuclear transition or particle annihilation

3.10
gamma-ray spectrometry

method of measuring gamma rays yielding the energy spectrum of the gamma radiation

3.11
pile-up

processing by a radiation spectrometer of pulses resulting from the simultaneous absorption of

particles, or photons, originating from different decaying nuclei, in the radiation detector

Note 1 to entry: As a result, they are counted as one single particle or photon with an energy between the

individual energies and the sum of these energies.
3.12
transition probability
fraction of the nuclei which disintegrates in a specific way
4 Symbols and units

For the purposes of this document, the symbols given in ISO 80000-10 and the following apply.

V Volume of the water sample for test, in litres

A Activity of each radionuclide in calibration source, at the calibration time, in

becquerels
cc,
Activity concentration of each radionuclide, without and with corrections, ex-
AA,c
pressed in becquerels per litre
“Volumic activity” is an alternative name for “Activity concentration".
t Test sample spectrum counting time, in seconds
t Background spectrum counting time, in seconds
t Time between the reference time and the measuring time
t Calibration spectrum counting time, in seconds

nn,,n Number of counts in the net area of the peak, at energy E, in the test sample spec-

NE,,NE0sNE,
trum, in the background spectrum and in the calibration spectrum, respectively
nn,,n

Number of counts in the gross area of the peak, at energy E, in the test sample spec-

gg,,EE0 gs,E
trum, in the background spectrum and in the calibration spectrum, respectively
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nn,,n Number of counts in the background of the peak, at energy E, in the test sample

bb,,EE0 bs,E

spectrum in the background spectrum and in the calibration spectrum, respectively

ε Efficiency of the detector at energy E at actual measurement geometry
P Probability of the emission of a gamma ray with energy E of each radionuclide,
per decay
Decay constant of each radionuclide, in reciprocal seconds

uc(),(uc ) Standard uncertainty associated with the measurement result, without and with

AA,c
corrections, in becquerel per litre
Expanded uncertainty calculated by Uk=⋅uc() with k = 1, 2..., in becquerel
per litre
Decision threshold, without and with corrections, in becquerel per litre
cc,
AA,c
# #
Detection limit, without and with corrections, in becquerel per litre
cc,
AA,c
Lower and upper limits of the probabilistically symmetric coverage interval, in
cc,
becquerel per litre

Lower and upper limits of the shortest coverage interval, in becquerel per litre

cc,
5 Principle
Gamma rays cause electron-hole pairs when interacting with matter. When a
...

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