Towards a probabilistic approach for risk analysis of nuclear-powered icebreakers using FMEA and FRAM

Abstract

Nuclear-powered icebreakers are widely used for escort and convoy operations in ice-covered Arctic waters to withstand the challenges from the harsh and rapidly changing environment. In addition, nuclear-powered icebreakers must confront other potential risks and accidents such as nuclear leakage, which is a substantial threat to maritime safety and the Arctic environment. This paper proposes a probabilistic risk analysis of nuclear-powered icebreakers for independent, escort, and convoy operations in ice-covered waters by incorporating a failure mode and effects analysis (FMEA) and a functional resonance analysis method (FRAM). First, we used an FMEA method to analyze failure modes and the associated effects of nuclear-powered icebreakers during independent, escort, and convoy operations. We identified dangerous navigational scenarios as failure modes, discussed the causes, and assessed these failure modes’ consequences and associated criticalities. Second, based on the identified critical accident scenarios, we used FRAM to model the evolution process of accident scenarios in ice-covered waters. Monte Carlo Simulation (MCS) was also used to calculate the coupling change values of each function, considering the influences from humans, Technological, and organizational aspects. We then proposed targeted risk control options (RCOs) for accident scenarios' essential functions and coupling changes.