Modeling and simulation of corrosion product activity in pressurized water reactors under power perturbations

An improved methodology is presented for simulation of coolant activation due to corro- sion products and impurities in a typical pressurized water reactor (PWR) under power per- turbations. Using time dependent production and losses of corrosion products in the primary coolant path an approach has been developed to calculate the coolant speci fic activity. Results for 24Na, 56Mn, 59Fe, 60Co and 99Mo show that the specific activity in primary loop approa- ches equilibrium value under normal operating conditions fairly rapidly. Predominant corro- sion product activity is due to 56Mn. Flow rate has been assumed to follow power changes and di€erent types of power perturbations are introduced after the equilibrium activity has been achieved. In particular the e€ects of linear changes in reactor operating power and power peaking on the corrosion product activity of the primary coolant have been studied