What is FERMAT?
FERMAT® (Fracture mechanics Evaluation of RPV MATerials) is an analytical program developed by the Central Research Institute of Electric Power Industry (CRIEPI) to calculate the failure frequency of reactor pressure vessels (RPVs) using probabilistic fracture mechanics (PFM).
This software has been developed as a Windows application in accordance with the Japanese guideline JEAG 4640-2018 [1], enabling users to easily create input data and perform analyses through a graphical use interface (GUI). On this webpage, both the executable files and the source code are available free of charge (See Note). allowing you to directly review the computational procedures used in the analysis.
- [1]Japan Electric Association, “Guideline for Calculating Failure Frequency of Reactor Pressure Vessel Based on Probabilistic Fracture Mechanics”, JEAG 4640–2018.
- Note: The copyright for FERMAT, including executable files and source code, is owned by CRIEPI, and you must agree to the license agreement before downloading.
What is PFM?
PFM (Probabilistic Fracture mechanics) provides a quantitative approach by calculating the probability and/or frequency of failure, rather than a simple “yes or no” assessment of whether a component will fail. Even when the likelihood of failure is extremely low and considered negligible, PFM rigorously computes the probability and expresses it as a numerical value. These values enable more in-depth discussions on safety and operational strategies based on risk.
To accurately calculate the probability of failure, detailed information about the target component must be provided, and numerous evaluation formulas and analytical methods need to be integrated to properly represent the statistical distribution of parameters. Additionally, a comprehensive assessment of results from multiple iterations of analysis is required. Therefore, a dedicated analytical program, such as FERMAT, is essential for conducting PFM analysis.