Integrated Life Cycle Management model developed by LPI, Inc.

In response to the technical challenges faced by aging plant systems and components at nuclear power plants (NPP), the Electric Power Research Institute (EPRI) funded a product entitled Integrated Life Cycle Management (ILCM) which was developed by LPI, Inc. The ILCM software is a quantitative tool that supports capital asset and component replacement decision-making at NPPs. ILCM is comprised of models that predict the probability of failure (PoF) over time for various high-value components such as steam generators, turbines, generators, etc. The PoF models allow the user to schedule replacements at the optimum time, thereby reducing unplanned equipment shutdowns and costs. Most recently, LPI updated the feedwater heater model to include a wide variety of heat exchangers. The heat exchanger model calculates the probability of the tubes, shell, or internals failing individually, and then accumulates the failures across the heat exchanger sub-components. The dominant degradation mechanisms addressed by the model include stress corrosion cracking, wear, microbiologically influenced corrosion, flow accelerated corrosion, and particle-induced erosion. The heat exchanger model combines physics-based algorithms and operating experience distributions to predict the cumulative PoF over time. The model is applicable to shell and tube heat exchangers and air-to-water heat exchangers. Many different types of fluids including open cycle fresh water, closed cycle fresh water, sea water, brackish water, air, closed cooling water, steam, oil, primary water, and condensate are included. For heat exchangers exposed to raw water on the tube side they are susceptible to IGSCC, wear, MIC, and erosion degradation. An example that was used was a heat exchanger that is 32 years old, has a history of minor pitting in the vertical copper-nickel tubes, has closed cycle fresh water on the tube side, operates 50% of the time, and has lubricating oil on the shell side. Benchmarking with utilities has found that the heat exchanger model accurately predicts heat exchanger PoFs for multiple types of nuclear power plant heat exchangers. Results illustrate that the ILCM’s heat exchanger model is a reliable tool that can be utilized to help make end-of-life replacement decisions to optimize long range planning and ultimately save utilities money. For more information please contact Consuelo Guzman-Leong at cguzman-leong@lpiny.com

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