Simulation of upper plenum injection plant duringreflood

Abstract

The simulation of the upper plenum injection plant behavior during the reflood has been performed by using the one dimensional two fluid code RELAP5/MOD2. The UPTE experimental findings are utilized for the nodalization of the reactor vessel. The initial and boundary condition for the simulation are taken from the blowdown calculation results with the KWU evaluation code systems. The comparision has been made between the cold leg injection case and the upper plenum injection case. The effect of the downcomer voiding on the reflood process has been shown by the reflood simulation without the heat structures in the dwoncomer. The multidimensional flow effect on the peak clad temperature has been quantified by utilizing the isolated channel during the core nodalization. This study shows that the simulation of UPI plant during reflood can be performed by utilizing RELAP5/MOD2.