Reactor thermal power calculation by heatbalance and the role of instrumentation andcontrol systems in power uprating of nuclearpower plants

An accurate and reliable calculation of reactor thermal power is essential both to makesure that the reactor stays within the limits of the safety analyses, and that the thermalpower stated in the licence is not exceeded. Improvements in the calculation of thermalpower through the increased accuracy of installed instrumentation or moresophisticated calculation algorithms may also provide opportunities to tightenuncertainty margins identified in the original licence and, in turn, to increase outputpower.A discussion of the relative importance of measurements accuracy for differentparameters entering reactor thermal power calculation is given in Section ۲. A furtherillustration of the effect of instrument errors on the accuracy of reactor powercalculation is given in section ۳.The first source of uncertainty discussed is failure to compensate for processparameters corrections due to the variation in fluid conditions from the measurementlocation to the location of interest would introduce unexpected reactor powercalculation errors..The second potential source of uncertainty in the calculated reactor power consideredis due to a reduction of instrument loop errors by using more modern instruments.The third source of uncertainty addressed in this paper is due to instrumentcalibration.

کلیدواژه ها:

Heat balance ، power uprating ، instrumentation ، measurement uncertainty ، sensitivity ، accuracy