RADIATION HEATING OF THERMOCOUPLE ABOVE FUEL ASSEMBLY
17th Symposium of AER on VVER Reactor Physics and Reactor Safety (2007, Yalta, Crimea (Ukraine, back then))
CORE SURVEILLANCE AND MONITORING. CFD ANALYSIS
It is important to determine the thermal power at the four VVER-440 type reactors at NPP Paks as well as at all the other reactors in the world. In these reactors the power is calculated from the difference between outlet and inlet measured temperature of cooler of primary circuit with accurate resistance thermometers. Otherwise this power is calculated on the 210 measurement of fuel assembly outlet temperature with thermocouples just above the fuels. These two calculated values – including bypass – show discrepancy. The calculated power from fuel outlet temperatures is higher than the calculated one from cooler inlet-outlet total power. Till that time we assume two reasons. One of them explains this discrepancy by imperfect mixing of cooler in head of fuels. This effect is investigated by more institutes.