Modelling of spent fuel pools of reinforced concrete for studying fracture propagation in a stainless steel liner

Abstract

The durability and integrity of stainless steel liners in pure water spent fuel pools under thermal load cycles are critical for the pool long-term functionality. This thesis investigates the effect of thermal load cycles on the propagation of fractures in stainless steel liners, a component that plays a vital role in maintaining the leak-tightness of such pools. The study aims to model the behaviour of stainless steel liners by utilizing two global pool models—one excluding liners, comprising only concrete and reinforcement, and the other including liners—allowed a comparative analysis. The standard design procedure involving a concrete-only model was challenged by adding a liner to the model that facilitates the study of fracture growth under steady state conditions including different combinations of surface temperatures of 10 to 45 degrees of centigrade and hydrostatic pressure. Results indicate that the assumed fractures within the liner do not propagate under the normal load conditions, and accidental load conditions were not included in this study. The conclusion drawn from this research is that the pool liner, even with pre-existing micro fractures, can maintain its leak-tightness and withstanding the slow thermal loading cycles studied over its intended extended design life.