SIST EN ISO 16646:2025

SLOVENSKI STANDARD
01-december-2025
Fuzijske naprave - Merila za načrtovanje in delovanje zadrževalnih in
prezračevalnih sistemov v objektih za fuzijo tritija in objektih za ravnanje s
fuzijskim gorivom (ISO 16646:2024)
Fusion installations - Criteria for the design and operation of confinement and ventilation
systems of tritium fusion facilities and fusion fuel handling facilities (ISO 16646:2024)
Fusionsanlagen - Kriterien für die Auslegung und den Betrieb von Einschluss- und
Lüftungssystemen von Tritiumfusionsanlagen und Anlagen zur Handhabung von
Fusionsbrennstoff (ISO 16646:2024)
Installations de fusion - Critères pour la conception et l'exploitation des systèmes de
confinement et de ventilation des installations de fusion avec tritium et des installations
de traitement des combustibles de fusion (ISO 16646:2024)
Ta slovenski standard je istoveten z: EN ISO 16646:2025
ICS:
13.280 Varstvo pred sevanjem Radiation protection
27.120.20 Jedrske elektrarne. Varnost Nuclear power plants. Safety
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 16646
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2025
EUROPÄISCHE NORM
ICS 13.280; 27.120.20
English Version
Fusion installations - Criteria for the design and operation
of confinement and ventilation systems of tritium fusion
facilities and fusion fuel handling facilities (ISO
16646:2024)
Installations de fusion - Critères pour la conception et Fusionsanlagen - Kriterien für die Auslegung und den
l'exploitation des systèmes de confinement et de Betrieb von Einschluss- und Lüftungssystemen von
ventilation des installations de fusion avec tritium et Tritiumfusionsanlagen und Anlagen zur Handhabung
des installations de traitement des combustibles de von Fusionsbrennstoff (ISO 16646:2024)
fusion (ISO 16646:2024)
This European Standard was approved by CEN on 22 September 2025.

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
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 16646:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
The text of ISO 16646:2024 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 16646:2025 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 March 2026, and conflicting national standards shall
be withdrawn at the latest by March 2026.
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 16646:2024 has been approved by CEN as EN ISO 16646:2025 without any modification.

International
Standard
ISO 16646
First edition
Fusion installations — Criteria
2024-06
for the design and operation
of confinement and ventilation
systems of tritium fusion facilities
and fusion fuel handling facilities
Installations de fusion — Critères pour la conception et
l'exploitation des systèmes de confinement et de ventilation
des installations de fusion avec tritium et des installations de
traitement des combustibles de fusion
Reference number
ISO 16646:2024(en) © ISO 2024
ISO 16646:2024(en)
© ISO 2024
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
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Email: copyright@iso.org
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Published in Switzerland
ii
ISO 16646:2024(en)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General confinement specificities of tritium fusion facilities or fusion fuel handling
facilities . 7
4.1 General .7
4.2 Inventories to identify for fusion facilities confinement .9
4.3 Specific systems or loads used in fusion facilities .10
4.4 General description of confinement systems for fusion facilities .10
4.4.1 General .10
4.4.2 First confinement system . 13
4.4.3 Secondary confinement system .14
4.4.4 Fuel cycle systems . 15
4.4.5 Tritium material compatibility . 15
5 Functions and safety aspects for confinement and ventilation systems .15
5.1 General . 15
5.2 Main functions .16
5.3 General principles .17
5.4 Risk assessment procedure . .17
5.4.1 Preliminary analysis .17
5.4.2 Risk evaluation.19
5.4.3 Safety classification . 20
6 Architecture and description of the different confinement systems .21
6.1 General .21
6.2 Static confinement of radioactive material .21
6.2.1 Containment barriers and systems .21
6.2.2 Isolation function (static containment) .21
6.3 Ventilation of the volumes within the first confinement system . 23
6.3.1 General . 23
6.3.2 Vacuum vessel exhaust process . 23
6.3.3 Primary containment pressure limiter . 23
6.3.4 Local and/or centralised detritiation system .24
6.3.5 Ventilation of the volume between first and second containment barriers of the
first confinement system .24
6.3.6 Cryogenic systems .24
6.4 Ventilation of the volumes within the second confinement system . 25
6.4.1 General . 25
6.4.2 Rooms and building ventilation systems. 25
6.4.3 Detritiation systems . 25
6.4.4 Local ventilation systems .
...