Pass 2 Calibration

Software Analysis Tool

Pass 2 Calibration Analysis is the determination of calibration status for each Wear Rate Analysis (WRA) run in the CHECWORKS™ SFA model. It involves using inspection data to adjust the CHECWORKS™ SFA algorithm predictions to better correlate with actual plant wear conditions. It also helps the user determine a degree of confidence in the model predictions.

Without a Pass 2 Analysis, all WRA runs in the CHECWORKS™ SFA are considered non-calibrated. This means Pass 2 Analysis results do not reflect actual plant conditions.

Relative FAC wear rates can be used, but the predicted remaining service life is not an indicator of the actual remaining life. Therefore, more inspections are required to understand wear trends in a WRA run, leading to additional inspections in low- wear areas of the plant.


GSE Engineering, Programs & Performance (formerly True North Consulting) has provided the nuclear industry with Flow Accelerated Corrosion (FAC) program support for the past twenty years. Our team of FAC program subject matter experts (SMEs) works with most of the US utilities in support of their FAC programs including performing a significant number of Pass 2 Calibrations each year.

GSE has developed an innovative Pass 2 Calibration tool built on our quality TSM Enterprise Software platform already in use at many utilities in the industry to support this and provide an additional benefit to the FAC industry. The Pass 2 Calibration tool will automate the overall process. thereby reducing the level of manual effort and reducing/eliminating potential human errors.


  • The automated process allows the assembly of all calibration data immediately, allowing the engineer to assess the calibration status
  • Live connection to your running CHECWORKS™ SFA database means no
  • Inclusion of advanced metrics such as Outlier Percent, Figure of Merit,
    Normalized Mean of Absolute Error, and more as recommended by
    NSAC-202L and CHUG Position Papers #9, #12, & #17
  • View scatter plots by line, geometry type, and pipe size to better determine the reason for trends or outliers within a wear rate analysis
  • Automated Reporting and Standardized Process
  • Reduction in time to train a new FAC engineer


  • Labor intensive effort to perform a Pass 2 Calibration manually. With no easy or quick way to gather the necessary data from CHECWORKS™, the process is manual, pulling each necessary piece of data by reviewing reports and counting elements to assemble a spreadsheet.
  • The manual effort process lends itself to potential human error. The overall manual process is iterative and requires the FAC program engineer to manipulate data causing room for error.
  • Each site has a ramp-up training/mentoring costs associated with bringing on a new FAC engineer to learn the manual process to perform a Pass 2 Calibration.