Feasibility study and fundamental hydrodynamic study about self-sealing concept for nuclear containment

Abstract

The containment building of the nuclear power plant acts as the leak-tight barrier. The containment building is composed of the Containment Liner Plate (CLP) and the thick concrete wall. The concrete is deteriorated by several reasons like the excessive freezing and thawing, and the corrosion of a reinforcement. If a crack that penetrates from the inside to the outside of the concrete wall occurs, the containment building cannot act as the leak-tight barrier anymore. Therefore, the self-sealing concept based on the Phase Change Material (PCM) that can repair cracks passively is suggested. This self-sealing concept applies the PCM to the containment building and seals the crack by the phase change properties of the PCM. The PCM permeate through a narrow gap since the size of most cracks are smaller than 3 mm. In this study, the self-sealing concept is briefly introduced and the feasibility of this concept is investigated by the code simulation. The hydrodynamic characteristics of the fluid is also analyzed by the microchannel flow experiment. In addition, the temperature greatly changes as the PCM flows through the crack, and viscosity changes much as the temperature changes. Accordingly, the effect of the viscosity on the microchannel flow experiment is investigated. At the same time, the influence of the roughness is discussed.