Assessment of Below-Grade Waterproofing for Nuclear Power Plants

This report evaluates the design, construction, and performance factors that affect below-grade waterproofing of deeply embedded (DE) nuclear power plants (NPPs). Given the long service life of DE NPPs, reliable waterproofing is essential to protecting critical spaces from groundwater intrusion. The study compares different types of waterproofing systems and evaluates geotechnical and structural factors, such as groundwater conditions, excavation methods, foundation support, and structure joint design, as well as their impact on performance. It also identifies design strategies that improve system resilience, including drainage, redundancy, monitoring, and implementing rigorous quality control and assurance (QA/QC) procedures during construction. The conclusions highlight the importance of a well-integrated design, which coordinates the disciplines of structural design and geotechnical engineering with the desired waterproofing performance. Lastly, recommendations are provided for a waterproofing framework to guide system selection, detailing, and maintenance planning for reliable long-term protection of nuclear facilities.