In recent years, significant experience of the effects of high wind and flooding on nuclear installations has been gained worldwide. These phenomena may simultaneously affect all the structures, systems and components important to safety at a nuclear installation site. By detailing the methodologies and providing case studies for the evaluation of meteorological and hydrological hazards, this publication supports IAEA Safety Standards Series No. SSG-18, Meteorological and Hydrological Hazards in Site Evaluation for Nuclear Installations. In the first part of the publication, wind hazards relating to tropical cyclones, tornadoes, extratropical storms, thunderstorms and wind-borne debris are discussed. The second part covers external flooding hazards (excluding tsunamis) relating to wind induced coastal flooding, wind generated waves on rivers, extreme precipitation and runoff events and the sudden release of impounded water.

• 1. INTRODUCTION
  • 1.1. Background
  • 1.2. Objective
  • 1.3. Scope
  • 1.4. Structure
• 2. GENERAL CONSIDERATIONS ON WIND HAZARDS
• 3. TROPICAL CYCLONES
  • 3.1. General considerations
  • 3.2. Tropical cyclone modelling
    • 3.2.1. Single point probabilistic models
    • 3.2.2. Track modelling
    • 3.2.3. Joint probability method
    • 3.2.4. Wind field modelling
    • 3.2.5. Other important model components
  • 3.3. Data sources
    • 3.3.1. Track modelling
    • 3.3.2. Hurricane parameterization
    • 3.3.3. End-to-end validation studies
  • 3.4. Modelling uncertainties
    • 3.4.1. Historical record, climate change and long period oscillations
• 4. TORNADO WINDS
  • 4.1. General considerations
  • 4.2. Tornado statistics and databases
    • 4.2.1. Tornado wind speeds and the F and EF scales
  • 4.3. Tornado hazard modelling
  • 4.4. Tornado hazard model uncertainties
    • 4.4.1. Uncertainty in occurrence rates
    • 4.4.2. F scale probability distributions
    • 4.4.3. F scale wind speed uncertainties
    • 4.4.4. Overall modelling uncertainty factor
• 5. EXTRATROPICAL STORMS, THUNDERSTORMS AND OTHER WINDSTORMS
  • 5.1. General considerations
  • 5.2. Data sources
  • 5.3. Statistical methods
    • 5.3.1. Thunderstorm winds
    • 5.3.2. Non-thunderstorm winds
  • 5.4. Estimating uncertainties
    • 5.4.1. Parameter uncertainty
    • 5.4.2. Modelling uncertainty
  • 5.5. Combined straight line wind hazard
  • 5.6. Tail limited distributions
• 6. WIND-BORNE DEBRIS
  • 6.1. General considerations
  • 6.2. Deterministic and probabilistic methods
    • 6.2.1. Tornado wind fields
    • 6.2.2. Hurricane wind fields as applied to wind-borne debris
    • 6.2.3. Trajectory models
    • 6.2.4. Characteristic tornado missile velocity statistics
  • 6.3. Missile impact effects
  • 6.4. Atmospheric pressure change loads
    • 6.4.1. Sealed buildings
    • 6.4.2. Vented buildings
  • 6.5. Missile surveys
    • 6.5.1. Plant missile survey procedure
• 7. GENERAL CONSIDERATIONS ON EXTERNAL FLOODING HAZARDS (EXCLUDING TSUNAMIS)
  • 7.1. General considerations
  • 7.2. Basis for flood hazard assessment
  • 7.3. Uncertainties in flood hazard assessment
  • 7.4. Hazard assessment and protection measures for floods
    • 7.4.1. Flood effects and specificities
    • 7.4.2. Protection principles
    • 7.4.3. Material protection measures
    • 7.4.4. Organizational protection measures
  • 7.5. Background elements for probabilistic flood hazard assessment
• 8. WIND INDUCED COASTAL FLOODING
  • 8.1. General considerations
  • 8.2. Data sources
  • 8.3. Deterministic assessment (using statistical analysis)
    • 8.3.1. Scenario definition
    • 8.3.2. Guidance for scenario characterization
  • 8.4. Elements of probabilistic assessment
• 9. WIND GENERATED WAVES ON RIVERs
  • 9.1. General considerations
  • 9.2. Data sources
  • 9.3. Hazard assessment
  • 9.4. Elements of probabilistic assessment
• 10. EXTREME PRECIPITATION AND RUNOFF EVENTS
  • 10.1. General considerations
  • 10.2. Data sources
  • 10.3. Hazard assessment
    • 10.3.1. Local rainfall
    • 10.3.2. Flooding in a small drainage basin
    • 10.3.3. Flooding in a large drainage basin
  • 10.4. Elements of probabilistic assessment
• 11. FLOODS DUE TO THE SUDDEN RELEASE OF IMPOUNDED WATER
  • 11.1. General considerations
  • 11.2. Data sources
  • 11.3. Hazard assessment
    • 11.3.1. Scenario definition
    • 11.3.2. Guidance for scenario characterization
  • 11.4. Elements of probabilistic assessment
• REFERENCES
• ABBREVIATIONS
• CONTRIBUTORS TO DRAFTING AND REVIEW