Development of a practical fiber optic system for in-situ, online monitoring of power cable degradation

The ability for the United States to maintain clean and secure energy production is heavily reliant on modernization and life extension of the current fleet of Light Water Reactors (LWRs) as well as the deployment of a new generation of advanced reactors that is on the horizon. A key challenge to LWR life extension is electrical cable insulation degradation. These polymeric materials, while ideal for their dielectric properties, cost-effectiveness, and flexibility, are inherently susceptible to environmental degradation exacerbated by radiation exposure, ultimately being one of the factors limiting plant lifespan. The proposed approach is applicable to both the current fleet of LWRs and the new generation of advanced reactors being built in the next decades. The proposed system will contribute to significantly reduce planned outages, inspections, maintenance, and ultimately lower the operating costs of NPPs. Lupine Materials, in collaboration with Penn Stateĺs Nuclear Engineering Department, proposes a transformative approach to address this challenge: an in-situ, online cable monitoring system utilizing distributed fiber optic sensors. This innovative system enables continuous monitoring of cable health by detecting minute changes in temperature and strain along the fiberĺs length, with millimeter-level spatial resolution. This real-time, in-situ monitoring offers significant advantages over existing methods. It eliminates the need for cable de-energization or plant outage, reducing costs and downtime associated with traditional inspections. Condition monitoring and early detection of degradation allows for targeted maintenance, improving safety and reliability by preventing potential failures before they occur. Additionally, the systemĺs compatibility with both existing and new cable designs ensures its broad applicability across the nuclear power industry. Phase I will focus on developing methods for integrating optical fibers into cable insulation, both for retrofitting existing cables and for incorporation into new cables for future NPP installations, demonstrating proof-of-concept for detection and localization of localized heating and strain, analyzing data signatures to classify degradation, and identify technical challenges to be addressed in Phase II.