PRESCON2 Simulation of the OECD/CSNI Containment International Standard Problem #23

Abstract

The prediction of pressure and temperature transients in containment following a loss-of-coolant accident is important in reactor safety analysis. Several computer codes have been written to solve the one-dimensional conservation equations describing the behaviour of the air/steam/water mixture inside the containment system. PRGSCON2 is one such computer code developed by AECL. Experimental results for blowdowns in a decommissioned PWR containment (HDR) have been obtained by the Federal Republic of West Germany in cooperation with several sponsors, and AECL together with several other organizations was asked to participate in a "blind" simulation of the experiment . This paper compares the "blind" predictions of PRESCON2 (based on a best estimate approach) with experimental results, and addresses possible modelling deficiencies, etc., to account/explain for the differences observed between the experimental and predicted results. The short term comparison results (0-5s) for pressure and temperature are quite good, within approximately 10%. For the medium and long term regimes (5-50s, and 5-12005), pressures are under predicted.