VOLUME 19 (Supplement)

Structural integrity assessment of radioactive waste storage trenches at the Philippines’ centralized radioactive waste management facility

This study evaluates the structural integrity of the reinforced concrete radioactive waste storage trenches (Trenches A, B, and C) at the Philippine Nuclear Research Institute (PNRI). Integrating non-destructive testing, destructive concrete coring, and ETABS dynamic modeling in accordance with the National Structural Code of the Philippines, the assessment revealed a severe, systemic degradation of the existing concrete matrix with a compressive strength of 12.77 MPa, below the 21 MPa seismic requirement. This material defect is responsible for various structural vulnerabilities, exposing a disconnect between the trenches' global geometric stiffness and their local member detailing. Structural analysis showed that Trench A failed drift checks, while Trenches B and C passed global drift checks but still exhibited localized member deficiencies. To mitigate radiological risk and align the facility with modern seismic standards, structural retrofitting is recommended, specifically utilizing reinforced concrete jacketing to restore column capacities and externally bonded Carbon Fiber Reinforced Polymers (CFRP) to strengthen roof slabs.