This Safety Guide provides recommendations on meeting the requirements of IAEA Safety Standards Series No. SSR-2/1 (Rev. 1) relevant to reactor containment and associated systems. The publication addresses the containment structure and the systems with the functions of isolation, control and management of mass and energy releases, control and limitation of radioactive releases, and control and management of combustible gases. The Safety Guide is intended for use primarily for land based, stationary nuclear power plants with water cooled reactors designed for electricity generation or for other heat generating applications, such as for district heating or desalination.

• 1. INTRODUCTION
  • Background
  • Objective
  • Scope
  • Structure
• 2. CONTAINMENT SAFETY FUNCTIONS AND THE DESIGN APPROACH
  • Safety functions
  • Confinement of radioactive material
  • Protection against external and internal hazards
  • Radiation shielding
• 3. DESIGN BASIS OF THE CONTAINMENT STRUCTURE AND ITS COMPONENTS AND ASSOCIATED SYSTEMS
  • General
  • Postulated initiating events
  • Internal hazards
  • External hazards
  • Accident conditions
    • General
    • Design basis accidents
    • Design extension conditions
  • Design limits
  • Reliability
    • Systems designed to mitigate design basis accidents
    • Safety features for design extension conditions without significant fuel degradation
    • Safety features for design extension conditions with core melting
  • Defence in depth
  • Practical elimination of conditions that could lead to an early radioactive release or a large radioactive release
  • Safety classification
  • Environmental qualification
  • Codes and standards
  • Use of probabilistic safety analyses in design
• 4. Design of the containment and its associated systems
  • General
    • Layout and configuration of the containment and its associated systems
    • Maintenance and accessibility
    • Operator actions
    • Sharing of parts of the containment systems between units
    • Ageing effects
    • Decommissioning
  • Structural design of containment
    • General design process
    • Loads and load combinations
    • Engineering criteria
    • Local stresses and fatigue
    • Ultimate capability and failure mode
  • Structural design of structures within the containment
    • In-vessel retention strategy
    • Ex-vessel retention strategy
  • Structural design of systems
  • Mass and energy release and management
    • Control of pressure and temperature in operational states
    • Control of pressure and temperature in accident conditions
  • Control and limitation of radioactive releases
    • Containment source term
    • Leaktightness of the containment
    • Secondary confinement building
    • Containment bypass
    • Reduction of radioactive material in the containment atmosphere
  • Management of combustible gases
    • Generation of combustible gases
    • Threats due to combustible gases in design extension conditions with core melting
    • Measures for the mitigation of hydrogen combustion and for the prevention of hydrogen combustion challenging the containment integrity
  • Mechanical features of the containment
    • Provisions for containment isolation of piping and ducting systems
    • Isolation valves
    • Penetrations
    • Air locks, doors and hatches
  • Materials
    • Concrete
    • Metallic materials
    • Soft sealing materials
    • Covering, cushioning, thermal insulation and coating materials
  • Instrumentation
    • Monitoring the stability of the containment
    • Detection of deviations from normal operation
    • Periodic testing of the containment leak rate
    • Monitoring of the availability of systems
    • Initiation of automatic operation of systems
    • Accident and post-accident monitoring
• 5. TESTS AND INSPECTIONS
  • Inspection during construction
  • Commissioning tests
    • Structural integrity test
    • Integrated leak rate tests of the containment envelope
    • Local leak rate tests of isolation devices, air locks and penetrations
    • Functional tests of equipment and wiring in the containment
  • In-service tests and inspections
    • Structural integrity tests
    • Integrated leak rate tests of the containment envelope
    • Visual inspection
• Appendix PLANTS DESIGNED TO EARLIER STANDARDS
• REFERENCES
• CONTRIBUTORS TO DRAFTING AND REVIEW