Containment leakage characterization with BARCOM test results for design and over pressure conditions

Abstract

BARC containment (BARCOM) is a 1:4 scale test model of 540MWe IPHWR which was constructed at Tarapur for carrying out leakage studies, at various overpressure conditions, apart from performing ultimate load capacity assessment of the containment model. Various leakage tests were conducted up to the design pressure (Phase II experiments) as well as beyond the design pressure (Phase III experiments).A mathematical model has been developed, by simulating the containment model, to assess the leakage contribution from containment model by various modes such as through the concrete porosity, penetrations and cracks. The modeling involves solving mass and energy equation for the containment together with the evaluation of stress and strain in containment structures and tendons which were further used for calculation of pre-stressing pressure and for estimating crack width. The paper presents the methodology adopted for leakage characterization studies, useful for nuclear containment performance assessment under beyond the design basis conditions. The limitations associated with the existing predictive leakage models based on the present study are highlighted with an objective to further improve these models in future based on the present experimental data and analysis methodology evolved in this paper.