The Light Water Reactor Sustainability Program is a research, development, and deployment program sponsored by the U.S. Department of Energy Office of Nuclear Energy. The program is operated in collaboration with the Electric Power Research Institute’s (EPRI’s) research and development efforts in the Long-Term Operations Program. The Long-Term Operations Program is managed as a separate technical program operating in the Plant Technology Department of the EPRI Nuclear Power Sector with the guidance of an industry advisory Integration Committee. Because both the Department of Energy Office of Nuclear Energy and EPRI conduct research and development in technologies enabling the operation of commercial light water reactors beyond the current 60- year license limits, it is important that the work be coordinated to the benefit of both organizations.
The Light Water Reactor Sustainability and Long-Term Operations Programs are working closely with nuclear utilities to develop instrumentation and control technologies and solutions to help ensure the safe life extension of current reactors, including centralized online monitoring. The current fleet of nuclear power plants (NPPs) performs periodic or condition-based maintenance of their active assets/components. The objective of centralized online monitoring (OLM) is to implement predictive online monitoring techniques that would enable NPPs to diagnose incipient faults, perform proactive maintenance, and estimate the remaining useful life (RUL) of the asset. Currently, there are two projects under centralized OLM: online monitoring of active components and online monitoring of passive components. The research activities presented here are associated with online monitoring of active components.
To implement predictive online monitoring, EPRI has developed a web- based Fleet-wide Prognostic and Health Management (FW-PHM) Software Suite (currently in Beta Version 1.1.1). The framework of the FW-PHM software consists of four main components: Diagnostic Advisor; Asset Fault Signature Database; RUL Advisor; and RUL Signature Database.
Part of the long-term strategic goal of centralized OLM of active components is to enable industry to employ online monitoring using the FW-PHM software on important active components. Emergency diesel generators (EDGs) are one of the systems selected for initial development of monitoring techniques, diagnostic and prognostic models. Idaho National Laboratory (INL) and EPRI have identified Braidwood Generating Station (owned by Exelon Corporation) as the partner utility for EDGs.
INL is performing research and working with Exelon to identify and characterize critical faults that lead to catastrophic failures in EDGs. This will allow INL to populate the asset fault signature database of the FW-PHM software. The asset fault signature database captures details about asset type, source of the fault information, and fault signatures, including features, causes, remedies, and consequences. Based on the identified fault signatures and failure modes, the Diagnostic Advisor is used to diagnose fault conditions.
INL will continue research on prognostic models for EDGs over the next two years. These models will be used to populate the RUL database and to make component life predictions using the RUL advisor. The resulting models will be used with data from the utility partner to demonstrate the benefit of predictive OLM in NPPs. The FW-PHM software is unique in the sense that it standardizes the diagnostic and prognostic approach across assets based on fault signatures and fault features, generates a comprehensive diagnosis report, and allows information sharing between different NPPs via a master database. As valuable historical operating data accumulate, the diagnostic and prognostic performance will improve significantly. These capabilities do not currently exist in NPPs, and are expected to support safer long term operation of the NPPs.