A FUNDAMENTAL-STUDY OF A WATER-JET INJECTED INTO A VACUUM VESSEL OF FUSION-REACTOR UNDER THE INGRESS OF COOLANT EVENT

As one of some transient sequences for the thermofluid safety in ITER, pressure rise and boiling heat transfer characteristics in a Tokamak vacuum vessel during an ingress of coolant event (ICE) are being inves tigated experimentally by using the preliminary ICE apparatus. The pre ssure rise rates in the vacuum vessel and the wall temperature distrib utions on the target plate were measured quantitatively and clarified at first. In addition, a two-phase flow under the ICE conditions was a nalyzed numerically for predicting the experimental results using one- dimensional transport equations and the drift-flux model. The experime ntal results were compared with the numerical results. It nas found th at the pressurization behavior during the ICE conditions could be esti mated qualitatively by the present numerical analyses.