A venting system for a casing containing an explosive material includes a base plug having one or more venting ports. A ring-shaped failure mechanism mounted to the base plug seals the venting ports. The failure mechanism has a selected melting temperature such that raising the temperature of the failure mechanism to its melting temperature causes the failure mechanism to unseal the venting port to allow controlled burning of the explosive material. An insert ring formed of a durable material to protect the failure mechanism from being damaged may be mounted on an outer surface of the failure mechanism. An adhesive may be used to seal gaps between the failure mechanism, the insert ring and the base plug. The failure mechanism may have a peripheral tab formed to fit within a corresponding groove in the base plug to mount the failure mechanism securely to the base plug.