Downtime and early burntime thermal response of the fusion power core of a pulsed fusion reactor

Transient thermal response of the Fusion Power Core (FPC) of a pulsed fusion reactor is analyzed numerically using a computer code developed for this purpose. In this code, the convection and conduction equations are solved simultaneously. The flow is assumed to be constant. The analysis models the outboard first wall and blanket of the He-cooled ARIES-IV fusion reactor. It is found that the first wall suffers the largest temperature fluctuation: and almost all of the sensible heat in it is removed within about 30 seconds. Since the thermal time constants of the blanket are much larger, temperature fluctuations are smaller in it. Also, only a part of the sensible heat in the blanket can be removed by the coolant during the downtime.