Risk Analysis of Hydrogen Gas from Battery System of Underwater Vehicles

There are different types of underwater vehicles each designed for a specific purpose. Battery powered propulsion is most commonly used in these vehicles. Our study focuses on a submarine which is a vital cog in defence system for any country across the world, offering a unique and strategic advantage in its maritime operations. Throughout history, submarines have undergone significant advancements, both in terms of their design and the technology that powers them. The propulsion system of a submarine is of utmost importance, as it determines its speed, range, and maneuverability. Broadly they are classified into conventional diesel powered battery operated submarines and the Nuclear submarines. One critical aspect of Conventional submarine technology is the battery system that enables these vessels to operate silently and efficiently beneath the surface. Nuclear powered vessels also have batteries as standby supply in case of an emergency. One of the primary concerns with battery systems is that they produce hydrogen gas as a by-product, which is highly flammable and can pose risks if not properly managed. Hydrogen gas management becomes highly critical in these atmospheres and mitigating the potential hazards associated with it requires the implementation of rigorous safety protocols and continuous monitoring technologies. Throughout the history of the submarine operations, there have been a large number of incidents that has occurred due to an explosive mixture of hydrogen and air present in the system becoming ignited and exploding. Due to the nature of submarine operations each situation is complex and possess unique challenges. The probabilistic safety assessment of hydrogen mitigation system and improving ways to mitigate hydrogen gas risk in submarines becomes more important considering the aging fleet across the world. The paper focuses on highlighting the key risk areas in the safety of the Main batteries and the associated systems using relevant Reliability techniques. All relevant data for the purpose of this study has been obtained from open sources.