Recent development and validation of physical models in the computer code INTRA

The INTRA code is specified by the ITER Joint Central Team and the European Community as a reference code for safety analyses of Tokamak type fusion r eactors. The code simulates pressure transients and chemical reactions with in the vacuum vessel and surrounding compartments resulting from system fai lure due to equipment malfunctions. During the last year considerable exten sions and improvements to INTRA have been made. Models for simulation of co unter-current flow of gases in a how junction and for internal heat generat ion sources, such as decay heat within heat slabs, surface heat loads and h eating or cooling devices, have been implemented. Applications and validati ons against different experiments, such as ICE and LOVA tests, have been ca rried out as part of these developments. The results show that INTRA, with the new models, has a reasonable agreement with the experimental results an d it has improved its capability to predict pressure, temperature and flow transients but some improvements are still necessary. (C) 2000 Elsevier Sci ence B.V. All rights reserved.