EN ISO 16646:2025 PDF

Overview

EN ISO 16646:2025 (ISO 16646:2024) provides criteria for the design and operation of confinement and ventilation systems in tritium fusion facilities and fusion fuel handling facilities. It targets installations with high tritium inventories (sites with tritium quantities greater than typical 10 g–100 g ranges) and covers specialized buildings such as hot cells, examination laboratories, emergency management centres, and radioactive waste treatment and storage facilities. The standard’s principal aim is to ensure radiation protection by preventing dissemination of airborne tritium contamination and protecting workers, the public and the environment.

Key Topics and Requirements

• Confinement architecture: Definitions and roles of first and secondary confinement systems, static containment barriers, and isolation functions specific to fusion installations.
• Ventilation system design: Requirements for dynamic confinement, negative pressure strategies, airflows between zones, air exchange optimization, duct layout, pressure-drop calculations and ventilation diagram development.
• Confinement classification: Procedures to classify areas into potentially contaminated zones and assign safety functions to ventilation and containment systems.
• Filtration and detritiation: Specification of HEPA filtration, air detritiation systems and other gas-trapping devices to control airborne tritium.
• Risk assessment and safety classification: Preliminary analysis, risk evaluation, and assignment of safety classes for systems and components.
• Special hazards management: Controls for combustible gases, cryogenic liquid/gas risks, ambient condition management, and ventilation requirements for control rooms and safety-classified components.
• Tritium compatibility: Considerations for materials and systems exposed to tritium and fusion-specific loads.

Applications and Who Uses This Standard

EN ISO 16646 is intended for professionals and organizations involved in the design, licensing, construction, operation and regulation of fusion installations that handle tritium:

• Design engineers and HVAC specialists developing confinement and ventilation systems for fusion fuel handling and fusion reactors.
• Nuclear safety and radiation protection engineers conducting risk assessments and safety classification.
• Facility operators and maintenance teams implementing operational controls, detritiation and filtration systems.
• Regulators and licensing authorities evaluating compliance with radiation protection and containment requirements.
• Architects and integrators planning layouts for hot cells, labs, waste treatment and emergency management centres.

Related Standards

EN ISO 16646 complements other national and international standards on radiation protection, nuclear facility safety, ventilation engineering and HVAC design. It was prepared by ISO/TC 85 and adopted by CEN as EN ISO 16646:2025 for harmonized application across CEN member states.

Keywords: EN ISO 16646, tritium, fusion installations, confinement and ventilation systems, detritiation, HEPA filters, radiation protection, tritium inventory, ventilation design.