NOVELTY - The system has an exhaust nozzle assembly comprising an exhaust nozzle (905). A shape memory alloy (SMA) seal retaining element (1007) captures and releases an end portion (1003) of a nozzle sealing element. The sealing element seals the exhaust nozzle during normal operation of batteries within a sealed battery pack enclosure i.e. nut (909). The retaining element allows the sealing element to be permanently ejected through the exhaust nozzle due to increased internal battery pack pressure that accompanies the batteries entering into thermal runaway.    USE - Battery pack thermal management system for use in an electric vehicle.    ADVANTAGE - The system exhausts hot gas and effluent generated during thermal runaway event occurring within the battery pack, thus minimizing effects of thermal runaway and risk of personal and property damage while reducing the chances of an initial event propagating throughout the pack. The system limits collateral damage and risk to responders. The system is simple to manufacture and repair and electrically interconnects the batteries in a convenient manner, and prevents contaminants such as road debris and moisture, from entering the battery pack during normal operation of the vehicle. The nozzle directs the flow of hot gas and material away from the passenger compartment and any location, thus minimizing risks to passengers, bystanders and responders and vehicle damage. The system minimizes risk of overheating the batteries within battery compartments. The battery pack is integrated into the vehicle's structure in order to improve vehicle performance such as vehicle stiffness and vehicle impact resistance.    DETAILED DESCRIPTION - The exhaust nozzle is made of a ceramic material.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of a portion of a battery pack that includes an exhaust nozzle assembly utilizing an SMA retention element to hold the seal within the exhaust nozzle.    Exhaust nozzle (905)    Nut (909)    End portion of nozzle sealing element (1003)    Dimples or continuous grooves (1005)    SMA seal retaining element (1007)