Statistical Component of Calibration Error of VVER In-Core Thermal Sensors

The results of the analysis of the random error of calibration of in-reactor thermocouples installed in a VVER are presented. It is shown that, from the point of view of metrological reliability, one of the promising variants of the calibration technique is an option based on comparing the readings of the calibrated thermocouple with the temperature, which is determined using the sum of the readings of loop resistance thermometers weighed with the coefficients of influence of each loop on the calibrated thermocouple. The coefficients of influence can be determined on the basis of correlations due to the thermohydraulic features of the circulation of the coolant in the main circulation circuit.