Development of a Thermo-Hydro-Mechanical Model of the Containment Vessel Vercors to Study Its Aging and Leak Tightness, Based on Specimen Tests and In Situ Measurements

Abstract

Abstract An important function of a reactor containment vessel is to provide sufficient leakage tightness during normal operation and severe accident condition. The purpose of this paper is to present a set of numerical models along with a study methodology to understand the mechanisms most responsible for aging and leakage tightness degradation of prestressed reinforced concrete containment vessels without liner. The solution proposed here is adapted to the study of full-size buildings while most research work dealing with this matter offers sophisticated modeling techniques mostly suitable for local studies.The methodology is applied to study the thermo-hydro-mechanical behavior of Vercors mock-up [1]. Vercors is an experimental mock-up of a reactor containment building at 1/3 scale (with diameter of 7.7 m, height of 20 m and thickness of 0.4 m) built at EDF Lab “Les Renardières” near Paris in 2015 to analyze the possibility of the life extensions of French Nuclear Power Plants. The mock-up is finely instrumented, and its behavior is monitored from the beginning of the construction. In the numerical application of our modelling methodology to Vercors mock-up, the thermo-hydro-mechanical models are all calibrated by considering first the material test specimen and then the in-situ measurements, to have a representative digital clone of the mock-up. All necessary models and resolution strategy are implemented in Code Aster® (EDF) finite elements program.KeywordsAgeing phenomena in concrete structuresDelayed strainsDamage and cracking of reinforced and prestressed concrete structuresAir transport in concrete