Development of a heat exchanger root-cause analysis methodology

The objective of this work is to determine a generic methodology for approaching the accurate identification of the root cause of component failure. Root-cause determinations are an everyday challenge to plant personnel, but they are handled with widely differing degrees of success due to the approaches, levels of diagnostic expertise, and documentation. The criterion for success is simple: If the root cause of the failure has truly been determined and corrected, the same causal failure relationship will not be demonstrated again in the future. The approach to root-cause analysis (RCA) element definition was to first selectively choose and constrain a functionally significant component (in this case a component cooling water to service water heat exchanger) that has demonstrated prevalent failures. Then a root cause of failure analysis was performed by a systems engineer on a large number of actual failure scenarios. The analytical process used by the engineer was documented and evaluated to abstract the logic model used to arrive at the root cause. For the case of the heat exchanger, the actual root-cause diagnostic approach is described. A generic methodology for the solution of the root cause of component failure is demonstrable for this general heat exchanger sample