A 1000 MW(t) sodium-cooled fast reactor has three identical coolant loops. The reactor vessel is tilled with sodium to a prescribed level, with the remainder of the vessel being occupied by an inert cover gas, as shown in Figure 7-26 . Under the steady operating condition, the ratio of the volume of cover gas to that of sodium in the primary system is 0. 1. At time t = 0, the primary system of this reactor suffersa complete loss of heat sink accident, and the reactor power instantly drops to 2% of full power. Using a lumped parameter approach, calculate the pressure of the primary system at time t = 60 seconds. At this time, check if the sodium is boiling.Usefu l dataInitial average primary system temperature = 980°FInitial primary system pressure = 50 psiTotal primary system coolant mass = 18,OOO Ibm
{3 (volumetric coefficient of thermal expansion of sodium) 1 .6( 10^(-4)) F
cp for sodium = 0.3 BTU/Ibm OF (at 980°F)
p(row) for sodium = 51.4 lbm/ft) (at 980°F)
Sodium saturated vapor pressure:p = exp [I8.832 - (13113/ T) - 1.0948 In T + 1.9777 (10^ - 4 T]where p is in atmospheres and T is in OK.