BS ISO 26802:2010 Nuclear facilities. Criteria for the design and the operation of containment and ventilation systems for nuclear reactors
BS ISO 26802 is an International Standard which specifies the applicable requirements related to the design and the operation of containment and ventilation systems of nuclear power plants and research reactors, taking into account the following.
For nuclear power plants, BS ISO 26802 addresses only reactors that have a secondary confinement system based on International Atomic Energy Agency (IAEA) recommendations.
For research reactors, BS ISO 26802 applies specifically to reactors for which accidental situations can challenge the integrity or leak-tightness of the containment barrier, i.e. in which a high-pressure or high-temperature transient can occur and for which the isolation of the containment building and the shutoff of the associated ventilation systems of the containment building is required.
For research reactors in which the increase of pressure or temperature during accidental situations will not damage the ventilation systems, the requirements applicable for the design and the use of ventilation systems are given in ISO 17873. However, the requirements of BS ISO 26802 can also be applied.
Contents of BS ISO 26802:
Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Functions ensured by the ventilation system
4.1 General
4.2 Main functions
5 Architecture and description of the different ventilation systems
5.1 Ventilation of the volumes within the primary containment envelope
5.2 Ventilation of the volumes located within the secondary confinement
5.3 Ventilation of the volumes located outside the secondary confinement
5.4 Miscellaneous ventilation systems not connected with containment envelopes
6 Safety aspects for ventilation systems
6.1 General principles
6.2 Risk assessment procedure — General
6.3 Risk assessment procedure for severe accidents
7 Requirements for the design of ventilation systems
7.1 Confinement of radioactive material
7.2 Filtration
7.3 Reactor specificities
8 Management of specific risks
8.1 Control of combustible gases in the reactor building
8.2 Management of ambient conditions
8.3 Prevention of risks linked to releases of heat, gases or toxic vapours
8.4 Prevention of risks linked to the deposition of matter in ventilation ducts
8.5 Prevention of fire hazard
8.6 Consideration of external hazards
9 Dispositions concerning the management and the operation of the ventilation systems
9.1 Organization and operating procedures
9.2 Technical operating instructions
9.3 Operational management issues
9.4 Test procedures and maintenance
9.5 Monitoring of the ventilation system
9.6 Control of the ventilation system to prevent fire hazards
10 Control and instrumentation
Annex A (informative) Typical radioactive products in nuclear reactors
Annex B (informative) Examples of general confinement concepts for nuclear power reactors
Annex C (informative) Examples of safety classification for nuclear power reactors
Annex D (informative) Examples of classification of working areas according to radiological contamination hazard
Annex E (informative) Example of classification of types of ventilation, according to radiological contamination hazard — Recommended ventilation configurations
Annex F (informative) Existing requirements for aerosol filters
Annex G (informative) Examples of loads to consider during the design of NPP ventilation systems
Annex H (informative) Typical values of leaktightness for containment and ventilation systems and periodicities of associated controls
Annex I (informative) Primary containment envelope status
Bibliography
