Guidelines for instrument calibration extension/reduction programs. Final report

Nuclear plants may need to consider plant-specific instrumentation performance for any of several reasons, including fuel-cycle extensions, Technical Specification surveillance extensions, calibration reduction programs, and instrument setpoint programs. Practical methods for analyzing historic instrument calibration data to predict instrument performance have not been well defined. Analysis methods were developed and applied to actual calibration data from seven nuclear plants. Over 800 individual instruments with over 20,000 calibration data points were evaluated to confirm the validity of the analysis methods. The methods are described fully in this report and examples are provided throughout to assist the user in applying the techniques. The report includes generic observations on instrument performance made during the project.