prEN ISO 16646

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)

This document specifies the applicable requirements related to the design and the operation of confinement and ventilation systems for fusion facilities for tritium fuels and tritium fuel handling facilities specific for fusion applications for peaceful purposes using high tritium inventories, as well as for their specialized buildings such as hot cells, examination laboratories, emergency management centres, radioactive waste treatment and storage facilities.
In most countries, a tritium quantity is declared as high for tritium inventories higher than a range of 10 g to 100 g. In the tritium fusion facilities in the scope of this document, the tritium inventory is deemed to be higher than this range for the whole site.
This document applies especially to confinement and ventilation systems that ensure the safety function of nuclear facilities involved in nuclear fusion with the goal to protect the workers, the public and the environment from the dissemination of radioactive contamination originating from the operation of these installations, and in particular from airborne tritium contamination with adequate confinement systems.

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)

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)

General Information

• Status: Not Published
• Publication Date: 19-Jul-2026
• ICS: 13.280 - Radiation protection
• ICS: 27.120.20 - Nuclear power plants. Safety
• 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: 4060 - Closure of enquiry - Enquiry
• Start Date: 21-Aug-2025
• Due Date: 24-Apr-2026
• Completion Date: 21-Aug-2025
• Ref Project: oSIST prEN ISO 16646:2025 - 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)

Standards Content (Sample)

SLOVENSKI STANDARD
01-julij-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: prEN ISO 16646
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.

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
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 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 . 26
6.4.5 Ventilation of the volumes located outside the secondary confinement . 26
6.4.6 Miscellaneous ventilation systems not connected with containment envelopes . 26
7 Requirements for the design of ventilation systems .27
7.1 General .27
7.2 Dynamic confinement .27
7.2.1 General .27
7.2.2 Classification of the installation into potentially contaminated areas
(confinement classification) . 28
7.2.3 Factors influencing the design of ventilation systems . 30
7.2.4 Negative pressure . 30

iii
ISO 16646:2024(en)
7.2.5 Air velocities between areas.31
7.2.6 Basic air pattern and clean-up systems .32
7.2.7 Classification into ventilation types . 33
7.2.8 Optimization of air exchanges . 33
7.2.9 Layout and location of the ventilation ducts .37
7.2.10 Elaboration of the ventilation diagram and calculation of the pressure drops .37
7.3 Filtration .37
7.3.1 General .37
7.3.2 HEPA filters . 38
7.3.3 Air detritiation system . 38
7.3.4 Other gas-trapping devices .41
8 Management of specific risks . 41
8.1 Control of combustible gases in the buildings.41
8.2 Control of cryogenic liquid/ gases in the buildings .42
8.3 Management of ambient conditions .42
8.3.1 Tritium airbor
...