Reliability and Availability Data System (RADS)
RADS is a database and analysis tool designed to estimate industry and plant-specific reliability and availability parameters for selected components in risk-important systems for use in risk-informed applications. RADS contains data and information based on actual operating experience from Industry Reporting and Information System (IRIS), formerly called the Equipment Performance Information Exchange System (EPIX), maintained by INPO. The information covers 1997 through the present. It also contains initiating events from October 1987 through the present; Loss of Offsite Power (LOOP) events, and Common Cause Failure (CCF) events.
Because IRIS data are proprietary, NRC provides the RADS database and the RADS analysis software, along with supporting technical documentation, only to nuclear power plant licensees who are members of INPO and NRC staff on request.
The reliability parameters estimated by RADS are as follows:
- Probability of failure on demand
- Failure rate during operation (used to calculate failure to run probability)
- Maintenance out-of-service unavailability (planned and unplanned)
- Initiating event frequencies
- Time trends in reliability parameters
INPO members or NRC staff can request access to the RADS database and analysis software at
A publicly available online reliability calculator is available at
Page Last Reviewed/Updated Monday, March 25, 2024