Guidance for gamma spectrometry measurement of radioactive waste (ISO 19017:2015)

ISO 19017:2015 is applicable to gamma radiation measurements on radioactive waste.
Radioactive waste can be found in different forms and exhibit a wide range of characteristics, including the following:
- raw or unconditioned waste, including process waste (filters, resins, control rods, scrap, etc.) and waste from dismantling or decommissioning;
- conditioned waste in various forms and matrices (bitumen, cement, hydraulic binder, etc.);
- very low level (VLLW), low level (LLW), intermediate level (ILW) and high level radioactive waste (HLW);
- different package shapes: cylinders, cubes, parallelepipeds, etc.
Guidance is provided in respect of implementation, calibration, and quality control. The diversity of applications and system realizations (ranging from research to industrial systems, from very low level to high level radioactive waste, from small to large volume packages with different shapes, with different performance requirements and allowable measuring time) renders it impossible to provide specific guidance for all instances; the objective of this International Standard is, therefore, to establish a set of guiding principles. Ultimately, implementation is to be performed by suitably qualified and experienced persons and based on a thorough understanding of the influencing factors, contributing variables and performance requirements of the specific measurement application.
This International Standard assumes that the need for the provision of such a system will have been adequately considered and that its application and performance requirements will have been adequately defined through the use of a structured requirements capture process, such as data quality objectives (DQO).
It is noted that, while outside the scope of this International Standard, many of the principles, measurement methods, and recommended practices discussed here are also equally applicable to gamma measurements of items other than radioactive waste (e.g. bulk food, water, free-standing piles of materials) or to measurements made on radioactive materials contained within non-traditional packages (e.g. in transport containers).

Leitfaden für gammaspektrometrische Messungen von radioaktivem Abfall (ISO 19017:2015)

Lignes directrices pour le mesurage de déchets radioactifs par spectrométrie gamma (ISO 19017:2015)

L'ISO 19017:2015 s'applique aux mesurages des rayonnements gamma dans les déchets radioactifs.
Les déchets radioactifs peuvent se présenter sous différentes formes et révéler des caractéristiques extrêmement diverses, notamment:
- les déchets bruts ou non conditionnés, y compris les déchets de procédé (filtres, résines, barres de contrôle, rebuts, etc.) et les déchets d'assainissement ou de démantèlement;
- les déchets conditionnés sous diverses formes et matrices (bitume, ciment, liant hydraulique, etc.);
- les déchets radioactifs de très faible activité (TFA), de faible activité (FA), de moyenne activité (MA) et, de haute activité (HA);
- les différentes formes de colis: cylindres, cubes, parallélépipèdes, etc.
Les préconisations données portent sur la mise en ?uvre, l'étalonnage et le contrôle qualité. La diversité des applications et des réalisations de systèmes (allant des activités de recherche aux systèmes industriels, des déchets radioactifs de très faible activité aux déchets de haute activité, des colis de faible volume aux colis de gros volume de différentes formes et avec des exigences de performances et des temps de mesure admissibles différents) ne permet pas de donner des préconisations spécifiques pour tous les scénarios possibles. L'objectif de l'ISO 19017:2015 est donc d'établir un ensemble de principes directeurs. En définitive, la mise en ?uvre doit être assurée par du personnel dûment qualifié et expérimenté, et être fondée sur une bonne compréhension des facteurs d'influence, des variables à prendre en compte et des exigences de performances de l'application de mesurage considérée.
L'ISO 19017:2015 a été élaborée selon l'hypothèse que le besoin de fournir un tel système a été dûment examiné et que ses exigences d'application et de performances ont été dûment définies selon un processus de collecte des exigences structuré, tel que les objectifs de qualité des données (DQO).
L'attention est portée sur le fait que, bien que cela ne relève pas du domaine d'application de l'ISO 19017:2015, nombre des principes, méthodes de mesure et pratiques recommandées décrits dans le présent guide s'appliquent également aux mesurages gamma réalisés sur des éléments autres que les déchets radioactifs (ex. aliments en vrac, eau, matériaux en vrac) ainsi qu'aux mesurages réalisés sur des matières radioactives contenues dans des colis non traditionnels (ex. dans des conteneurs de transport).

Navodilo za merjenje aktivnosti radioaktivnih odpadkov z gama spektrometrijo (ISO 19017:2015)

Standard ISO 19017:2015 se uporablja za merjenje sevanja gama žarkov radioaktivnih odpadkov.
Radioaktivni odpadki so lahko različnih oblik in imajo različne lastnosti, pri čemer so vključeni:
– neobdelani ali nekondicionirani odpadki, vključno s procesnimi odpadki (filtri, smole, krmilni drogovi, odpadna kovina itd.) in odpadki, ki nastanejo pri razstavljanju ali izločitvi iz uporabe;
– kondicionirani odpadki različnih oblik in matric (bitumen, cement, hidravlično vezivo itd.);
– odpadki z zelo nizko radioaktivnostjo (VLLW), nizko radioaktivnostjo (LLW), srednjo radioaktivnostjo (ILW) in visoko radioaktivnostjo (HLW);
– embalaže različnih oblik: cilindrične, kockaste, paralelpipedne itd.
Podane so smernice v zvezi z uvajanjem, umerjanjem in nadzorom kakovosti. Raznolikost načinov uporabe in realizacij sistemov (od raziskovalnih do industrijskih sistemov z različnimi zahtevami glede zmogljivosti in dovoljenim časom merjenja za različne odpadke, od odpadkov z zelo nizko radioaktivnostjo do odpadkov z visoko radioaktivnostjo, ter embalaže, od embalaž majhne prostornine do embalaž velike prostornine različnih oblik) onemogoča oblikovanje posebnih smernic za vse primere. Namen tega mednarodnega standarda je torej oblikovati niz vodilnih načel. Uvajanje mora temeljiti na podrobnem razumevanju dejavnikov, vplivnih spremenljivk in zahtev glede zmogljivosti določene meritve, izvesti pa ga mora ustrezno usposobljeno in izkušeno osebje.
Ta mednarodni standard predpostavlja, da je potreba po zagotavljanju takega sistema ustrezno premišljena ter da so bile uporaba in zahteve glede zmogljivosti sistema ustrezno opredeljene z uporabo strukturiranega postopka za določanje zahtev, kot je določanje ciljev glede kakovosti podatkov (DQO).
Upoštevati je treba, da se številna načela, merilne metode in priporočene prakse, ki so opisani v tem mednarodnem standardu, vendar ne spadajo na področje njegove uporabe, lahko uporabijo tudi za merjenje sevanja gama žarkov snovi, ki niso radioaktivni odpadki (npr. hrana v večjih količinah, voda, samostojni materiali) ali za meritve, opravljene na radioaktivnih materialih, vsebovanih v neobičajnih embalažah (npr. v transportnih zabojnikih).

General Information

Status
Published
Public Enquiry End Date
31-May-2017
Publication Date
07-Nov-2017
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
19-Oct-2017
Due Date
24-Dec-2017
Completion Date
08-Nov-2017

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SLOVENSKI STANDARD
SIST EN ISO 19017:2017
01-december-2017
Navodilo za merjenje aktivnosti radioaktivnih odpadkov z gama spektrometrijo
(ISO 19017:2015)

Guidance for gamma spectrometry measurement of radioactive waste (ISO 19017:2015)

Leitfaden für gammaspektrometrische Messungen von radioaktivem Abfall (ISO
19017:2015)

Lignes directrices pour le mesurage de déchets radioactifs par spectrométrie gamma

(ISO 19017:2015)
Ta slovenski standard je istoveten z: EN ISO 19017:2017
ICS:
13.030.30 Posebni odpadki Special wastes
17.240 Merjenje sevanja Radiation measurements
27.120.30 Cepljivi materiali in jedrska Fissile materials and nuclear
gorivna tehnologija fuel technology
SIST EN ISO 19017:2017 en,fr,de

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

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SIST EN ISO 19017:2017
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SIST EN ISO 19017:2017
EN ISO 19017
EUROPEAN STANDARD
NORME EUROPÉENNE
October 2017
EUROPÄISCHE NORM
ICS 17.240; 27.120.30
English Version
Guidance for gamma spectrometry measurement of
radioactive waste (ISO 19017:2015)

Lignes directrices pour le mesurage de déchets Leitfaden für gammaspektrometrische Messungen von

radioactifs par spectrométrie gamma (ISO radioaktivem Abfall (ISO 19017:2015)
19017:2015)
This European Standard was approved by CEN on 13 September 2017.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this

European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references

concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN

member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by

translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management

Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,

Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels

© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 19017:2017 E

worldwide for CEN national Members.
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SIST EN ISO 19017:2017
EN ISO 19017:2017 (E)
Contents Page

European foreword ....................................................................................................................................................... 3

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SIST EN ISO 19017:2017
EN ISO 19017:2017 (E)
European foreword

The text of ISO 19017:2015 has been prepared by Technical Committee ISO/TC 85 “Nuclear energy,

nuclear technologies, and radiological protection” of the International Organization for Standardization

(ISO) and has been taken over as EN ISO 19017:2017 by Technical Committee CEN/TC 430 “Nuclear

energy, nuclear technologies, and radiological protection” the secretariat of which is held by AFNOR.

This European Standard shall be given the status of a national standard, either by publication of an

identical text or by endorsement, at the latest by April 2018, and conflicting national standards shall be

withdrawn at the latest by April 2018.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

According to the CEN-CENELEC Internal Regulations, the national standards organizations of the

following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,

Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,

France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,

Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and the United Kingdom.
Endorsement notice

The text of ISO 19017:2015 has been approved by CEN as EN ISO 19017:2017 without any modification.

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SIST EN ISO 19017:2017
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SIST EN ISO 19017:2017
INTERNATIONAL ISO
STANDARD 19017
First edition
2015-12-15
Guidance for gamma spectrometry
measurement of radioactive waste
Lignes directrices pour le mesurage de déchets radioactifs par
spectrométrie gamma
Reference number
ISO 19017:2015(E)
ISO 2015
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SIST EN ISO 19017:2017
ISO 19017:2015(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2015, Published in Switzerland

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form

or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior

written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of

the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2015 – All rights reserved
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SIST EN ISO 19017:2017
ISO 19017:2015(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

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

2 Terms and definitions ..................................................................................................................................................................................... 1

3 Application ................................................................................................................................................................................................................. 7

3.1 General ........................................................................................................................................................................................................... 7

3.2 Typical applications ............................................................................................................................................................................ 7

4 Measurement equipment ............................................................................................................................................................................ 8

4.1 General ........................................................................................................................................................................................................... 8

4.2 Open detector geometry ................................................................................................................................................................. 8

4.3 Collimated detector geometry ................................................................................................................................................10

4.4 Components of gamma measurement system ..........................................................................................................13

4.4.1 Mechanical equipment.............................................................................................................................................13

4.4.2 Radiation detection equipment .......................................................................................................................14

4.4.3 Data acquisition and analysis unit .................................................................................................................14

4.4.4 Electrical control ...........................................................................................................................................................14

4.4.5 Additional equipment ........................................................................................................................................... ....14

5 Calibration ...............................................................................................................................................................................................................14

5.1 General ........................................................................................................................................................................................................14

5.2 Peak energy and shape calibration of the gamma spectrometry system ..........................................15

5.3 Efficiency calibration of the gamma spectrometry system ...........................................................................15

5.4 Attenuation correction techniques .....................................................................................................................................18

6 Data evaluation ...................................................................................................................................................................................................18

6.1 Data processing steps.....................................................................................................................................................................18

6.2 Calculation of net peak count rates ....................................................................................................................................19

6.3 Calculation of gamma activity inventory of the waste package .................................................................20

6.4 Calculation of measurement uncertainty ......................................................................................................................20

6.5 Calculation of detection limit...................................................................................................................................................21

7 Quality assurance .............................................................................................................................................................................................23

7.1 General ........................................................................................................................................................................................................23

7.2 Record of calibration, validation, and waste measurements .......................................................................23

7.3 Documentation and procedures ...........................................................................................................................................24

7.4 Quality control ......................................................................................................................................................................................24

7.5 Competence ............................................................................................................................................................................................25

Annex A (informative) Examples of application of the techniques and methods discussed

within this International Standard ................................................................................................................................................26

Bibliography .............................................................................................................................................................................................................................47

© ISO 2015 – All rights reserved iii
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SIST EN ISO 19017:2017
ISO 19017:2015(E)
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 meaning of ISO specific terms and expressions related to conformity

assessment, as well as information about ISO’s adherence to the WTO principles in the Technical

Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information

The committee responsible for this document is ISO/TC 85, Nuclear energy, nuclear technologies, and

radiological protection, Subcommittee SC 5, Nuclear fuel cycle.

This first edition of ISO 19017 cancels and replaces ISO 14850-1:2006, which, in particular, did not

take into account segmented measurements performed with collimators, the possible use of numerical

simulation for calibration and uncertainty assessment, and gamma radiation detectors other than high-

purity germanium semiconductors.
iv © ISO 2015 – All rights reserved
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SIST EN ISO 19017:2017
ISO 19017:2015(E)
Introduction

A variety of non-destructive assay techniques are routinely used within the nuclear industry to

measure or provide information to otherwise enable quantification of the radionuclide inventory of

packages containing radioactive materials. This International Standard specifically considers gamma

spectrometry measurements made on packages containing radioactive waste.

The methods and techniques discussed within this International Standard find application in the

routine assay of various types of radioactive waste, packaged in a variety of ways, employing a variety

of container sizes, and types. They range from basic techniques, which have been in use for many years,

through to state of the art techniques that have been developed because of the increasing variety and

forms being assayed and the demands to satisfy increasingly challenging performance criteria.

Where guidance is provided, this is viewed as best current practice and is based on experience of

operating quantitative gamma spectrometry measurement systems, within a variety of applications,

for the purpose of providing radionuclide identification and activity information.

The objective of this International Standard is to promote a consistent approach to gamma spectrometry

measurements made on packages containing radioactive waste.
© ISO 2015 – All rights reserved v
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SIST EN ISO 19017:2017
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SIST EN ISO 19017:2017
INTERNATIONAL STANDARD ISO 19017:2015(E)
Guidance for gamma spectrometry measurement of
radioactive waste
1 Scope

This International Standard is applicable to gamma radiation measurements on radioactive waste.

Radioactive waste can be found in different forms and exhibit a wide range of characteristics, including

the following:

— raw or unconditioned waste, including process waste (filters, resins, control rods, scrap, etc.) and

waste from dismantling or decommissioning;

— conditioned waste in various forms and matrices (bitumen, cement, hydraulic binder, etc.);

— very low level (VLLW), low level (LLW), intermediate level (ILW) and high level radioactive waste

(HLW);
— different package shapes: cylinders, cubes, parallelepipeds, etc.

Guidance is provided in respect of implementation, calibration, and quality control. The diversity of

applications and system realizations (ranging from research to industrial systems, from very low

level to high level radioactive waste, from small to large volume packages with different shapes, with

different performance requirements and allowable measuring time) renders it impossible to provide

specific guidance for all instances; the objective of this International Standard is, therefore, to establish

a set of guiding principles. Ultimately, implementation is to be performed by suitably qualified and

experienced persons and based on a thorough understanding of the influencing factors, contributing

variables and performance requirements of the specific measurement application.

This International Standard assumes that the need for the provision of such a system will have

been adequately considered and that its application and performance requirements will have been

adequately defined through the use of a structured requirements capture process, such as data quality

objectives (DQO).

It is noted that, while outside the scope of this International Standard, many of the principles,

measurement methods, and recommended practices discussed here are also equally applicable to

gamma measurements of items other than radioactive waste (e.g. bulk food, water, free-standing piles

of materials) or to measurements made on radioactive materials contained within non-traditional

packages (e.g. in transport containers).
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

NOTE Definitions presented here are confined mainly to those terms not defined in common nuclear

material glossaries or whose use is specific to this document. Important key terms are repeated here for the

convenience of the reader.
2.1
assay

procedure to determine quantitatively the amount of one or more radionuclides of interest

contained in a package
© ISO 2015 – All rights reserved 1
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SIST EN ISO 19017:2017
ISO 19017:2015(E)
2.2
attenuation

physical process based on interaction between a radiation source and matter placed in the path of the

radiation that results in a decrease in the intensity of the emitted radiation

Note 1 to entry: Attenuation experienced in non-destructive assay (NDA)(2.27) of waste packages includes self-

attenuation (2.37) by the radioactive material itself as well as attenuation effects in the waste matrix (2.23),

internal barrier(s) and external container(s).
2.3
attenuation correction factor

used to correct (compensate) for the effect of attenuation within an NDA measurement equal to the

ratio between the un-attenuated and the attenuated radiation flux

Note 1 to entry: After attenuation correction the measured quantity is considered to be representative of the un-

attenuated activity of the radioactive substance assayed.
2.4
bias
estimate of a systematic measurement error
2.5
calibration standard
primary standard

designated or widely acknowledged as having the highest metrological qualities and whose value is

accepted without reference to other standards of the same quantity

Note 1 to entry: The calibration standard should be physically, radiologically, and chemically similar to the items

to be assayed, for which the activity of the radionuclide(s) of interest and all relevant properties to which the

measurement technique is sensitive are known with sufficient accuracy.
[SOURCE: www.french-metrology.com]
2.6
calibration

set of operations that establish, under specific conditions, the relationship between values of quantities

indicated by a measuring system, or values represented by a material measure or a reference material

and the corresponding values realized by Standards

Note 1 to entry: The result of a calibration permits either the assignment of values of measurands to the

indications or the determination of indications with respect to indications.

Note 2 to entry: A calibration may also determine other metrological properties such as the effect of

influence quantities.

Note 3 to entry: The result of a calibration may be recorded in a document, sometimes called a calibration

certificate or a calibration report.
[SOURCE: www.french-metrology.com]
2.7
collimation

method to restrict the field of view of the detector to specific parts of the item to be measured

Note 1 to entry: A shield around the side of the detector that still allows the detector to view the entire item is

technically not a collimator. Such shielding does not change the efficiency of the detector due to its presence.

2.8
collimator

device for collimating the radiation beam, usually constructed from highly attenuating material(s) such

as tungsten or lead. Collimators can be of parallel wall type or divergent
2 © ISO 2015 – All rights reserved
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SIST EN ISO 19017:2017
ISO 19017:2015(E)
2.9
collimated (detection) geometry

measurement configuration where only a part of a waste package can contribute to the response of the

detection system

Note 1 to entry: The whole activity is measured by scanning the entire package, or by assuming that the part

of the package within the detector’s field of view during one or more measurements is representative of the

entire package.
2.10
compton continuum

continuous pulse amplitude spectrum due to Compton electrons released in a detector

Note 1 to entry: The full-energy peaks are superimposed to this continuum and their “net areas” are determined

by subtracting the average Compton level estimated below each peak, as detailed in ISO 11929 for instance.

[SOURCE: IEC 60050-395:2014]
2.11
container

vessel into which the waste form (2.41) is placed for handling, transport, storage and/or eventual disposal

Note 1 to entry: Also the outer barrier protecting the waste from external intrusions.

[SOURCE: IAEA Radioactive Waste Management Glossary 2003 Edition]
2.12
coverage factor

although the combined standard deviation is used to express the uncertainty of many measurement

results, for some commercial, industrial, and regulatory applications (e.g. when health and safety

are concerned), what is often required is a measure of uncertainty that defines an interval about the

measurement result within which the value of the measurand can be confidently asserted to lie

Note 1 to entry: The measure of uncertainty intended to meet this requirement is termed expanded uncertainty

and is obtained by multiplying the standard deviation by a coverage factor, suggested symbol k. In general, the

value of the coverage factor k is chosen on the basis of the desired level of confidence to be associated with the

interval within which the true value is supposed to lie.
[SOURCE: http://physics.nist.gov/cuu/Uncertainty/coverage.html]
2.13
data quality objectives process
DQO

seven stage requirements capture process used to determine the type, quantity, and quality of data

needed to support a decision

Note 1 to entry: The purpose of this process (published by the US Environmental Protection Agency) is to

provide general guidance to organizations on developing data quality criteria and performance specifications for

decision making.
2.14
dead time
non-operative time of the detection system during the measurement period

Note 1 to entry: The length of time, directly following an instance of detection, associated with signal processing,

during which the system is not able to process further gamma events. This is a system performance parameter

which is usually expressed as a percentage of the measurement period. The measured counts would be less than

the actual counts due to the dead time and hence needs to be corrected.
© ISO 2015 – All rights reserved 3
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SIST EN ISO 19017:2017
ISO 19017:2015(E)
2.15
decision threshold

value of the estimator of the measurand, which when exceeded by the result of an actual measurement

using a given measurement procedure of a measurand quantifying a physical effect, one decides that

the physical effect is present

Note 1 to entry: The decision threshold is defined, such that in cases, where the measurements result, y, exceeds

the decision threshold, y*, the probability that the true value of the measurand is zero is less or equal to a chosen

probability, α.

Note 2 to entry: If the result, y, is below the decision threshold, y*, the result cannot be attributed to the physical

effect; nevertheless it cannot be concluded that it is absent.
[SOURCE: ISO 11929:2010, 3.6]
2.16
detection geometry

describe the extent of detector collimation with respect to the item to be measured

Note 1 to entry: Two principle assay configurations are distinguished in this guideline: collimated geometry and

open geometry.
2.17
detection limit

smallest true value of the measurand which ensures a specified probability of being detectable by the

measurement procedure

Note 1 to entry: With the decision threshold defined above, the detection limit is the smallest true value of the

measurand for which the probability of wrongly deciding that the true value of the measurand is zero is equal to

a specified value, β, when, in fact, the true value of the measurand is not zero.

[SOURCE: ISO 11929:2010, 3.7]
2.18
emission computed tomography
ECT

NDA method which allows the distribution of nuclide activity to be determined within sections of the

waste package

Note 1 to entry: The technique is based upon the measurement spectra from segments of the waste matrix which

the detector views through a collimator. In order to obtain accurate results, it is necessary to know the matrix

density distribution within the section (or in 3D), typically by Transmission Computed Tomography (TCT) (2.38).

Note 2 to entry: ECT is also referred to as Tomographic Gamma Scanning (TGS) (2.39).

2.19
full-energy peak

peak of the gamma spectrum corresponding to the complete deposition of the energy of a photon

emitted by a radionuclide

Note 1 to entry: No energy loss has occurred by photon interaction in the waste package or by the escape of

secondary photons from the detector following the interaction(s) of the primary photon leading to its detection.

2.20
full width at half maximum
FWHM
width of a gamma-ray peak at half of the maximum of the peak distribution

Note 1 to entry: This parameter is used to describe energy resolution. FWHM is often quoted when defining

detector performance (e.g. FWHM for a given energy, such as 662 keV). FWHM can be given in energy units (e.g.

keV) or in % if normalized to the gamma-ray energy.
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SIST EN ISO 19017:2017
ISO 19017:2015(E)
2.21
intrinsic detection efficiency

number of counts in the full-energy peak (2.19) at a given energy E (net area after subtraction of the

Compton continuum and other sources of background in the gamma spectrum) divided by the number

of photons at that energy that enter the detector
2.22
live time
difference between the measurement period and the dead-time
2.23
matrix
waste matrix

non-radioactive materials inside a waste package (2.29) in which the radioactive substances are dispersed

2.24
measurand
particular quantity subject to measurement
[SOURCE: ISO 11929:2010, 3.2]
2.25
measurement accuracy

closeness of agreement between a measured quantity value and a true quantity value of a measurand

2.26
measurement period
time frame over which the measurement is made
2.27
non-destructive assay
NDA

procedure based on the observation of spontaneous or stimulated nuclear radiation, interpreted to

estimate the content of one or more radionuclides in the item which is under investigation, without

affecting the physical or chemical form of the material
2.28
open (detection) geometry
measurement configuration where all parts of a waste package (2.29) can cont
...

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