EN ISO 9978:2022

Radiation protection - Sealed sources - Leakage test methods (ISO 9978:2020)

This document specifies the different leakage test methods for sealed sources. It gives a comprehensive set of procedures using radioactive and non-radioactive means.
This document applies to the following situations:
—     leakage testing of test sources following design classification testing in accordance with ISO 2919[1];
—     production quality control testing of sealed sources;
—     periodic inspections of the sealed sources performed at regular intervals, during the working life.
Annex A of this document gives guidance to the user in the choice of the most suitable method(s) according to situation and source type.
It is recognized that there can be circumstances where special tests, not described in this document, are required.
It is emphasized, however, that insofar as production, use, storage and transport of sealed radioactive sources are concerned, compliance with this document is no substitute for complying with the requirements of the relevant IAEA regulations[17] and other relevant national regulations. It is also recognized that countries can enact statutory regulations which specify exemptions for tests, according to sealed source type, design, working environment, and activity (e.g., for very low activity reference sources where the total activity is less than the leakage test limit).

Strahlenschutz - Umschlossene radioaktive Stoffe - Dichtheitsprüfungen (ISO 9978:2020)

Dieses Dokument beschreibt die verschiedenen Dichtheitsprüfverfahren für umschlossene radioaktive Stoffe. Es gibt eine umfangreiche Liste von Verfahren an, die sowohl mit als auch ohne Verwendung von radioakti¬ven Stoffen arbeiten.
Dieses Dokument gilt für die folgenden Situationen:
–   Dichtheitsprüfung an Prüfstrahlern nach Baumusterprüfungen zur Klassifizierung nach ISO 2919 [1];
–   Dichtheitsprüfung zur Qualitätssicherung bei der Herstellung von umschlossenen radioaktiven Stoffen;
–   wiederkehrende Prüfungen der umschlossenen radioaktiven Stoffe, die in regelmäßigen Abständen wäh-rend ihrer Nutzungsdauer durchgeführt werden.
Anhang A dieses Dokuments gibt dem Anwender eine Orientierungshilfe bei der Auswahl des/r am besten geeigneten Verfahren(s), je nach Situation und Typ des Strahlers.
Unter bestimmten Umständen können Prüfungen erforderlich sein, die in diesem Dokument nicht beschriebe-nen sind.
Es wird jedoch darauf hingewiesen, dass die Anwendung dieses Dokuments in Bezug auf Herstellung, Ver-wendung, Lagerung und Transport von Strahlern die Erfüllung der Anforderungen der einschlägigen IAEA-Vorschriften [17] und anderer einschlägiger nationaler Vorschriften nicht ersetzt. Nationale Regelungen kön-nen erlassen werden, die Ausnahmen für Prüfungen in Abhängigkeit von der Art der umschlossenen radioak-tiven Stoffe, ihrer Konstruktion, der Arbeitsumgebung und der Aktivität festlegen (z. B. für Referenzquellen mit sehr geringer Aktivität, bei denen die Gesamtaktivität unter dem Grenzwert für die Dichtheitsprüfung liegt).

Radioprotection - Sources scellées - Méthodes d’essai d’étanchéité (ISO 9978:2020)

Le présent document spécifie les différentes méthodes d'essai d'étanchéité pour les sources scellées. Il propose un ensemble complet de modes opératoires utilisant des moyens radioactifs et non radioactifs.
Le présent document s'applique aux situations suivantes:
—          essais d'étanchéité de sources d'essai suivant les essais de classification théorique selon l'ISO 2919[1];
—          essais de contrôle de la qualité de production de sources scellées;
—          contrôles périodiques des sources scellées effectués à intervalles réguliers pendant la durée de vie en service.
L'Annexe A du présent document donne des recommandations à l'utilisateur dans le choix de la ou des méthodes les plus appropriées en fonction de la situation et du type de source.
Il est admis que, dans certaines circonstances, des essais spéciaux non décrits dans le présent document sont nécessaires.
Il faut souligner cependant que, dans la mesure où la production, l'utilisation, le stockage et le transport des sources radioactives scellées sont concernés, la conformité au présent document ne peut se substituer aux exigences des règlementations de l'AIEA[17] et d'autres règlementations nationales pertinentes. Il est reconnu également que les pays peuvent édicter des règlementations qui spécifient des exemptions aux essais, en fonction du type de source scellée, de la conception, de l'environnement de travail et de l'activité (par exemple, pour les sources étalons de très faible activité dont l'activité totale est inférieure à la limite de l'essai d'étanchéité).

Zaščita pred sevanjem - Zaprti viri - Metode preskušanja prepuščanja (ISO 9978:2020)

Ta dokument določa različne metode preskušanja prepuščanja za zaprte vire. Zagotavlja celovit niz postopkov z uporabo radioaktivnih in neradioaktivnih sredstev.
Ta dokument se uporablja za naslednje primere:
– preskušanje prepuščanja preskusnih virov po preskusu klasifikacije zasnove v skladu s standardom ISO 2919[1];
– preskušanje nadzora kakovosti proizvodnje zaprtih virov;
– periodično pregledovanje zaprtih virov v rednih časovnih intervalih med življenjsko dobo.
V dodatku A tega dokumenta so podane smernice uporabnikom za izbiro najustreznejše metode oziroma metod glede na posamezen primer in vrsto vira.
Ugotovljeno je, da so lahko v določenih okoliščinah potrebni posebni preskusi, ki niso opisani v tem dokumentu.
Ob tem je treba poudariti, da skladnost s tem dokumentom v zvezi s proizvodnjo, uporabo, skladiščenjem in prevozom zaprtih radioaktivnih virov ne nadomešča izpolnjevanja zahtev ustreznih predpisov Mednarodne agencija za atomsko energijo (IAEA)[17] in drugih ustreznih nacionalnih predpisov. Ugotovljeno je tudi, da lahko države sprejmejo zakonske predpise, ki določajo izjeme za preskuse glede na vrsto zaprtega vira, zasnovo, delovno okolje in aktivnost (npr. za referenčne vire z zelo nizko aktivnostjo, pri katerih je skupna aktivnost manjša od meje preskusa prepuščanja).

General Information

• Status: Published
• Publication Date: 20-Dec-2022
• ICS: 13.280 - Radiation protection
• Technical Committee: CEN/TC 430 - Nuclear energy, nuclear technologies, and radiological protection
• Drafting Committee: CEN/TC 430 - Nuclear energy, nuclear technologies, and radiological protection
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 21-Dec-2022
• Due Date: 30-Sep-2024
• Completion Date: 21-Dec-2022
• Ref Project: SIST EN ISO 9978:2023 - Radiation protection - Sealed sources - Leakage test methods (ISO 9978:2020)

Overview

EN ISO 9978:2022 - Radiation protection - Sealed sources - Leakage test methods (ISO 9978:2020) specifies standardized procedures to detect and characterise leakage from sealed radioactive sources. The standard covers both radioactive and non‑radioactive test techniques and is intended for use in design testing, production quality control and periodic in‑service inspections throughout a sealed source’s working life. It also provides guidance (Annex A) on choosing appropriate methods by source type and situation.

Key topics and requirements

• Scope and purpose
  • Defines leakage test methods applicable after ISO 2919 design classification tests, during production QC, and for routine periodic inspections.
  • Emphasises that following this standard does not replace compliance with IAEA and national regulatory requirements.
• Test methods by radioactive means
  • Immersion tests (hot, boiling, room temperature, liquid scintillator techniques).
  • Gaseous emanation tests (radium‑226, krypton‑85 and other specific gaseous tests).
  • Wipe tests (wet and dry wipes) with absolute acceptance criteria (no correction for wiping efficiency).
• Test methods by volumetric means
  • Helium mass spectrometer leak testing (referencing ISO 20485 procedures and acceptance calculations).
  • Bubble leakage tests (vacuum, hot‑liquid, gas pressurisation, liquid nitrogen variants) with cautions about visibility and self‑heated sources.
  • Water pressurisation tests.
• Quality and competency
  • Measurement uncertainty must be considered when interpreting non‑binary results.
  • Personnel performing leak tests shall be appropriately trained and qualified (informative reference to ISO 9712).
• Guidance
  • Annex A provides practical guidance on selecting the most suitable method(s) for specific source designs and use cases.
  • Recognises that special or additional tests may sometimes be required.

Applications and users

• Manufacturers of sealed radioactive sources - for production QC and design verification following ISO 2919.
• Calibration and reference source producers - to confirm long‑term integrity.
• Radiation Protection Officers and service organizations - for routine leak testing and periodic inspections.
• Regulatory bodies and transport/storage managers - to verify compliance and support safety assessments.
• Test laboratories - implementing helium leak testing, immersion assays, wipe sampling and gaseous emanation measurements.

Related standards and references

• ISO 2919 - Sealed radioactive source classification (design testing)
• ISO 20485 - Tracer gas (helium) leak testing methods
• ISO 19361, ISO 19581 - Assay techniques for immersion test samples (informative)
• ISO 7503‑2 - Wipe testing techniques (informative)
• Relevant IAEA regulations and applicable national statutory requirements

By standardising leakage test methods for sealed sources, EN ISO 9978 helps organisations implement consistent radiation protection practices, choose appropriate test strategies, and document leak‑testing procedures for regulatory and quality assurance purposes. Keywords: sealed sources leakage test, radiation protection, EN ISO 9978, helium leak testing, immersion test, wipe test, gaseous emanation.

Standards Content (Sample)

SLOVENSKI STANDARD
01-marec-2023
Zaščita pred sevanjem - Zaprti viri - Metode preskušanja prepuščanja (ISO
9978:2020)
Radiation protection - Sealed sources - Leakage test methods (ISO 9978:2020)
Strahlenschutz - Umschlossene radioaktive Stoffe - Dichtheitsprüfungen (ISO
9978:2020)
Radioprotection - Sources scellées - Méthodes d’essai d’étanchéité (ISO 9978:2020)
Ta slovenski standard je istoveten z: EN ISO 9978:2022
ICS:
13.280 Varstvo pred sevanjem Radiation protection
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 9978
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2022
EUROPÄISCHE NORM
ICS 13.280
English Version
Radiation protection - Sealed sources - Leakage test
methods (ISO 9978:2020)
Radioprotection - Sources scellées - Méthodes d'essai Strahlenschutz - Umschlossene radioaktive Stoffe -
d'étanchéité (ISO 9978:2020) Dichtheitsprüfungen (ISO 9978:2020)
This European Standard was approved by CEN on 18 December 2022.

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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 9978:2022 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
The text of ISO 9978:2020 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 9978:2022 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 June 2023, and conflicting national standards shall be
withdrawn at the latest by June 2023.
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.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
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, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 9978:2020 has been approved by CEN as EN ISO 9978:2022 without any modification.

INTERNATIONAL ISO
STANDARD 9978
Second edition
2020-07
Radiation protection — Sealed sources
— Leakage test methods
Radioprotection — Sources scellées — Méthodes d’essai d’étanchéité
Reference number
ISO 9978:2020(E)
©
ISO 2020
ISO 9978:2020(E)
© 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.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

ISO 9978:2020(E)
Contents Page
Foreword .iv
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Requirements . 3
5 Test methods by radioactive means . 5
5.1 Immersion tests . 5
5.1.1 Immersion test (hot liquid) . 5
5.1.2 Immersion test (boiling liquid) . 5
5.1.3 Immersion test with a liquid scintillator . 6
5.1.4 Immersion test at room temperature . 6
5.1.5 Acceptance criteria . 6
5.2 Gaseous emanation tests . 6
5.2.1 Gaseous emanation test by absorption (for radium-226 sealed sources) . 6
5.2.2 Gaseous emanation test by immersion with a liquid scintillator (for
radium-226 sealed sources) . 6
5.2.3 Gaseous emanation test (for krypton-85 sealed sources) . 6
5.2.4 Other gaseous emanation tests . 7
5.2.5 Acceptance criteria . 7
5.3 Wipe tests . 7
5.3.1 Wet wipe test . . . 7
5.3.2 Dry wipe test . 7
5.3.3 Acceptance criteria . 7
6 Test methods by volumetric means . 7
6.1 Helium mass spectrometer leakage tests . 8
6.1.1 Helium test [equivalent to leak test type B6 in ISO 20485] . 8
6.1.2 Helium pressurisation test [equivalent to leak test type B5 in ISO 20485] . 8
6.1.3 Acceptance criteria . 9
6.2 Bubble leakage tests . 9
6.2.1 Vacuum bubble test [equivalent to immersion technique using vacuum in
[6] 9
EN 1593 . .
6.2.2 Hot-liquid bubble test [equivalent to immersion technique using liquid at
[6]
elevated temperature in EN 1593 . 9
6.2.3 Gas pressurisation bubble test [equivalent to immersion technique using
[6]
pressurisation of the object in EN 1593 . 9
6.2.4 Liquid nitrogen bubble test .10
6.2.5 Acceptance criteria .10
6.3 Water pressurisation test .10
Annex A (informative) Guidance for the choice of the tests to be carried out according to
purpose and sealed source type .11
Bibliography .13
ISO 9978:2020(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 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 85, Nuclear energy, nuclear technologies,
and radiological protection, Subcommittee SC 2, Radiological protection.
This second edition cancels and replaces the first edition (ISO 9978:1992), which has been technically
revised. The main changes compared to the previous edition are as follows:
— Clause 4: Revised to add text specifying factors to be considered in designing an effective leak
testing regime for a particular type of sealed source;
— Clause 4: Requirement added that personnel performing leak tests be appropriately trained and
qualified, informative reference to ISO 9712 added;
— Clause 4: Requirement added that measurement uncertainty shall be considered in sentencing non-
binary test results;
— Table 1 — “Threshold detection values and limiting values for different test methods” has been
revised for clarity;
— 5.1: Informative reference to suitable assay techniques for immersion test liquid samples added:
ISO 19361 and ISO 19581;
— 5.1.1, 5.1.2, 5.1.4: Composition of suitable immersion test liquids clarified;
— 5.3: Informative reference to suitable wipe testing techniques (ISO 7503-2) added and clarification
that acceptance criteria is absolute without correction for wiping efficiency required;
— 6.1: Normative reference to ISO 20485 added for methods of helium leak testing and calculation of
acceptance limits;
— 6.2: Cautionary text added to state that efficacy of tests assume ideal conditions for vision of bubbles;
— 6.2.1: Cautionary text added regarding bubble testing of self-heated sources;
iv © ISO 2020 – All rights reserved

ISO 9978:2020(E)
— A.1: Text expanded to clarify which tests to use under given circumstances.
ISO 9978:2020(E)
Introduction
The use of sealed sources has become so widespread that standards to guide the user, manufacturer
and regulatory agencies are necessary. When establishing these standards, radiation protection is the
prime consideration.
The purpose of this document, in conjunction with ISO 2919, is to minimise the risk to the public caused
by leakage of radioactive material into the general environment.
Leakage test methods for sealed sources were standardised in the first edition of this document. The
experience acquired since this date has necessitated the revision of this document.
vi © ISO 2020 – All rights reserved

INTERNATIONAL STANDARD ISO 9978:2020(E)
Radiation protection — Sealed sources — Leakage test
methods
1 Scope
This document specifies the different leakage test methods for sealed sources. It gives a comprehensive
set of procedures using radioactive and non-radioactive means.
This document applies to the following situations:
[1]
— leakage testing of test sources following design classification testing in accordance with ISO 2919 ;
— production quality control testing of sealed sources;
— periodic inspections of the sealed sources performed at regular intervals, during the working life.
Annex A of this document gives guidance to the user in the choice of the most suitable method(s)
according to situation and source type.
It is recognized that there can be circumstances where special tests, not described in this document,
are required.
It is emphasized, however, that insofar as production, use, storage and transport of sealed radioactive
sources are concerned, compliance with this document is no substitute for complying with the
[17]
requirements of the relevant IAEA regulations and other relevant national regulations. It is also
recognized that countries can enact statutory regulations which specify exemptions for tests, according
to sealed source type, design, working environment, and activity (e.g., for very low activity reference
sources where the total activity is less than the leakage test limit).
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 20485:2017, Non-destructive testing — Leak testing — Tracer gas method
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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
capsule
protective envelope, used to prevent leakage of radioactive material
ISO 9978:2020(E)
3.2
dummy sealed source
facsimile of a sealed source, the capsule of which has the same construction and is made with exactly the
same materials as those of the sealed source that it represents, but containing, in place of the radioactive
material, a substance resembling it as closely as is practical in physical and chemical properties
3.3
leachable
soluble in water, yielding quantities greater than 0,1 mg/g in 100 ml of still water maintained
at 50 °C for 4 h
3.4
leakage
transfer of contained radioactive material from the sealed source to the environment
3.5
leaktight
term applied to sealed sources which, after undergoing leakage testing, meet the acceptance criteria
Note 1 to entry: The acceptance criteria are given in Table 1.
3.6
model designation
manufacturer’s unique term (number, code or a combination of these) which is used to identify a specific
design of sealed source
3.7
non-destructive test
test used to detect internal, surface and concealed defects or imperfections in materials, using
techniques that do not damage or destroy the items being tested
3.8
non-leachable
insoluble in water, yielding quantities less than 0,1 mg/g in 100 ml of still water maintained at 50 °C for 4 h
3.9
sealed source
radioactive material sealed in a capsule or associated with a material to which it is closely bonded, this
capsule or bonding material being strong enough to maintain leaktightness of the sealed source under
the conditions of use and wear for which it was designed
3.10
simulated sealed source
facsimile of a sealed source, the capsule of which has the same construction and is made with exactly the
same materials as those of the sealed source that it represents but it contains, in place of the radioactive
material, a substance resembling it as closely as possible in physical and chemical properties and trace
quantities of radioactive material
Note 1 to entry: The tracer is in a form soluble in a solvent which does not attack the capsule and has the maximum
activity compatible with its use in a containment enclosure.
3.11
standard helium leakage rate
5 3 3
helium leakage rate at an upstream pressure of 10 Pa ± 5 × 10 Pa and a downstream pressure of 10 Pa
or less at a temperature of 296 K ± 7 K (23 °C ± 7 °C)
1)
Note 1 to entry: In this document, the unit Pascal cubic meter per second is used .
−6 3 −l 3 −1 −5 3 −1 −5 −1 −3
1) [1 × 10 Pa·m · s = 1 µPa·m ·s ≈ 10 atm·cm ·s ≈ 1 × 10 mbar·l·s ≈ 7, 5 × 10 lusec.]
2 © ISO 2020 – All rights reserved

ISO 9978:2020(E)
3.12
test source
sample used in the performance tests, having the same material and construction as sealed sources of
the model for which classification is being established
Note 1 to entry: A test source may be a simulated sealed source, a dummy sealed source or production source.
Note 2 to entry: The performance tests are described in ISO 2919.
4 Requirements
The tests described in this document are all designed to test and verify that the sealed source is
leaktight. However not all tests are applicable in all circumstances. Correct application and choice of
test method and testing media is critically important in designing an effective leak test programme.
Factors to be considered include:
— the chemical form of the active material if leak test is by radioactive means;
— the type of test liquid used in immersion tests;
— the number of encapsulations;
— the internal void volume when tests are carried out by volumetric means;
— the temperature of the sealed source;
— the suitability of the test method for the environment in which it is being performed;
— the reason for performing the test (integrity testing of a test source, production leakage tests,
routine in service testing);
— the required sensitivity and acceptance criteria.
The test programme for test and production sealed sources should be considered as part of the design
process and validated or justified as appropriate to demonstrate its effectiveness and sensitivity. This
process may include the analysis of historic data.
The tests described in this document shall be designed, validated and carried out by competent and
qualified persons who have demonstrable appropriate training in the applied test methods. For test
methods by radioactive means, the persons shall also have appropriate training in radiation protection
and measurement.
NOTE 1 Qualification and certification methods for non-destructive testing personnel can be found in
[2]
ISO 9712 .
An evaluation should be made of uncertainty in the case of non-binary test results (e.g. radiation
measurements on immersion test samples) and taken account of in sentencing the result.
Guidance for choosing suitable tests are specified in Annex A.
According to the test type and the sealed source type, at least one of each of the tests described
in Clauses 5 and 6 should be carried out [see Annex A for the choice of the test(s)].
It should be noted that it is best practice to carry out more than one type of leakage test and also to
perform a final wipe as a contamination check.
The tests described in this document do not form an exhaustive list, and other test methods may be
developed. However, in the case where a special test, which is not described in this document, is carried
out (see Clause 1), the organisation shall validate that the applied method is at least as effective as
the corresponding method(s) given in this document in order to be able to claim compliance with this
document.
ISO 9978:2020(E)
At the conclusion of the performed test(s), the sealed source shall be considered to be leaktight if it
complies with the acceptance criteria specified in Table 1.
It has been asserted that there is correspondence between the acceptance criteria for volumetric and
radioactive leak tests. Whilst there is no universally accepted basis for this assertion, experience has
shown that sources meeting the acceptance criteria shown in Table 1 have not subsequently been found
to leak.
3 −1 3 −1
NOTE 2 A leakage rate of 10 µPa · m · s for non-leachable solid contents and a rate of 0,1 µPa · m · s for
leachable solids and liquids was historically considered to be equivalent to the activity release limit of 2 000 Bq
[18]
(≈50 nCi) .
NOTE 3 A further confirmation of the volumetric acceptance threshold is given by Reference [8]. A leakage
−7 3 −1
rate of 10 atm · cm · s or more based on dry air at 298 K (25 °C) and for a pressure difference of 1 atm against
−2
a vacuum of 10 atm (equivalent to or less) is considered to represent a loss of leaktightness, irrespective of the
physical nature of the content.
Table 1 — Threshold detection values and limiting values for different test methods
Acceptance criteria
a
Test method Subclause Threshold of detection
Non-leachable Leachable or
content gaseous content
Radioactive methods
Immersion test (hot liquid) 5.1.1 (10 to 1) Bq <200 Bq <200 Bq
Immersion test (boiling
5.1.2 (10 to 1) Bq <200 Bq <200 Bq
liquid)
Immersion test with a
5.1.3 (10 to 1) Bq <200 Bq <200 Bq
liquid scintillator
Immersion test at room
5.1.4 (10 to 1) Bq <200 Bq <200 Bq
temperature
<200 Bq
Gaseous emanation test 5.2.1 (4 à 0,4) Bq Unsuitable
( Rn/12 h)
Emanation test with a <200 Bq
5.2.2 (0,4 to 0,004) Bq Unsuitable
liquid scintillator ( Rn/12 h)
Gaseous emanation test
<4 000 Bq
(for krypton-85 sealed 5.2.3 (10 to 1) Bq Unsuitable
( Kr/24 h)
sources)
Wet wipe test 5.3.1 (10 to 1) Bq <200 Bq <200 Bq
Dry wipe test 5.3.2 (10 to 1) Bq <200 Bq <200 Bq
Non-radioactive methods – Helium tests Standard helium leakage rate
−2 −4
Helium test (10 to 10 )
3 −1 3 −1
6.1.1 <1 µPa · m · s <0,01 µPa · m · s
3 −1
(He filling before sealing) µPa · m · s
Helium pressurisation test
−2 3 −1 3 −1 3 −1
6.1.2 (1 to 10 ) µPa · m · s <1
...