The use of the COMPACT code for calculation of long term environmental effects as a result of high temperature discharges into confined areas

COMPACT is a computer code used to provide long term thermo-hydraulic safety analysis both for buildings associated with light water nuclear reactors and other similar structures. This paper discusses the main features of the code and the validation programme, which has been put in place to establish its ability to predict accurately the environmental conditions within the containment of a reactor. In particular the experience gained in modelling the hydrogen tests performed in the HDR reactor building is described.