Reactor Operational Experience Results and Databases

This area contains updated results for a variety of previously published studies conducted by the Office of Nuclear Regulatory Research.

• The Loss of Offsite Power and Initiating Events updates are performed and made available yearly. The latest updates using data through calendar year 2022 are now available. The next updates that use data through calendar year 2023 will be conducted in 2024.
• The Component Performance and System Studies updates for component and system reliability and trending analysis are performed and reported every other year since 2016. The latest updates using data through calendar year 2022 for component and system studies are now available The next updates will use data through calendar year 2024 and be conducted in 2025.
• The Industry Average Parameter Estimates and Common-Cause Failure Parameter Estimates used in the SPAR models are updated every four or five years, which include initiating event frequencies, component unreliability, component unavailability, common cause failure alpha factors, and loss of offsite power nonrecovery probabilities. The latest updates using data through calendar year 2020 are now available. The next updates are planned to use data through calendar year 2025 and will be conducted around 2026.

Summary

• What’s New in the 2022 Update
  
• Summary of Analyses and Significant Trends for 2022
  
• Overview and Reference

Parameter Estimates

• Industry Average Parameter Estimates
• Common-Cause Failure Parameter Estimates
• Loss of Offsite Power
• Industry Performance of Relief Valves

Trends and Insights

• Initiating Events
• System Studies
• Component Performance
• Common-Cause Failure Insights
• International Common-Cause Failures

Supplemental Information

• Operating Time
• Other Documents
• Published Report List

Databases and Programs

• NRC Reactor Operating Experience Data (NROD)
• Reliability Calculator