Risk Assessment: Tools, Techniques, and Their Applications

22.2 Case Study 2: Overview

Hydrazine is a rocket fuel that is used in the space shuttle and in today's modern fighter jets. It is a suspected human carcinogen, corrosive, highly toxic, sensitizer; liver, kidney, nervous system, blood, and lung toxin; skin and eye hazard; as well as an odorless, colorless combustible liquid. An amount as little as 1 oz may be considered a spill. When a spill occurs, an emergency response team is dispatched to stop and contain that spill. The emergency team consists of two elements: the base fire department and the hydrazine response team.

The following section presents an analysis of a hydrazine spill. Seven primary events were identified and an event tree was constructed. The event tree graphically represented the process flow. The event tree was analyzed and actions that may cause a failure of the process were identified. Next, a preliminary hazard analysis (PHA) was performed. An analysis of the PHA helped identify what actions may fail and the way in which these actions might fail. The PHA led to the development of the fault tree. The fault tree facilitates a systematic computer analysis of the actions involved and their effects. Where applicable, the failure of an action to achieve the desired results was analyzed. The mode in which the failure occurred, the effects of such a failure, and an attempt to determine just how critical to the safe stoppage, containment, and clean up of the spill that failure was will be analyzed. Safety of the personnel ...