Transient temperature distribution in the reactor vessel wall

Transient heat conduction in the reactor vessel wall is investigated by considering the temperature dependence of thermal conductivity. The problem is described by a nonlinear partial differential equation, which is numerically simulated to show the transient temperature distribution in the reactor vessel wall due to failure of the reactor cooling system. The orthogonal collocation method is employed to tackle the nonlinear simulation and found to be quite accurate in predicting the transient temperature response. It is observed that the effect of variable thermal conductivity is very significant and, in many real circumstances, predictions of the transient temperature distributions will not be adequate without taking into account the variable thermal conductivity. (Auth.)