Online Monitoring to Enable Improved Diagnostics, Prognostics and Maintenance

For both existing and new plant designs there are increasing opportunities and needs for the application of advanced online surveillance, diagnostic and prognostic techniques. These methods can continuously monitor and assess the health of nuclear power plant systems and components. The added effectiveness of such programs has the potential to enable holistic plant management, and minimize exposure to future and unknown risks. The 'NDE & On-line Monitoring' activities within the Advanced Instrumentation, Information and Control Systems (II&CS) Pathway are developing R&D to establish advanced condition monitoring and prognostics technologies to understand and predict future phenomena, derived from plant aging in systems, structures, and components (SSC). This research includes utilization of the enhanced functionality and system condition awareness that becomes available through the application of digital technologies at existing nuclear power plants for online monitoring and prognostics. The current state-of-the-art for on-line monitoring applied to active components (eg pumps, valves, motors) and passive structure (eg core internals, primary piping, pressure vessel, concrete, cables, buried pipes) is being reviewed. This includes looking at the current deployment of systems that monitor reactor noise, acoustic signals and vibration in various forms, leak monitoring, and now increasingly condition-based maintenance (CBM) for active components. The NDEmore » and on-line monitoring projects are designed to look beyond locally monitored CBM. Current trends include centralized plant monitoring of SSC, potential fleet-based CBM and technology that will enable operation and maintenance to be performed with limited on-site staff. Attention is also moving to systems that use online monitoring to permit longer term operation (LTO), including a prognostic or predictive element that estimates a remaining useful life (RUL). Many, if not all, active components (pumps, valves, motors etc.) can be well managed, routinely diagnosed, analyzed and upgraded as needed using a combination of periodic and online CBM. The ability to successfully manage passive systems and structures is seen as the key to LTO, particularly in the USA. New approaches will be demonstrated, including prognostics for passive structures, which is critical to maintaining safety and availability and to reducing operations and maintenance costs for NPP's. To provide proactive on-line monitoring that includes estimates for RUL new projects will include advanced sensors, better understanding of stressors and challenges faced in quantification of uncertainty associated with RUL. This program area will leverage insights from past experience in other industries and seek to demonstrate the feasibility of on-line monitoring and prognostics to support NPP LTO.« less