Non-watertight door performance experiments and analysis under flooding scenarios

Nuclear power plant flooding can cause extensive damage. A more robust understanding of nuclear power plant performance in flooding scenarios can help identify weaknesses and opportunities for improvement. However, the performance of various components under flooding conditions is not well characterized. Limited component flooding performance characterizations interfere with comprehensive risk analysis and understanding potential economic impacts. To help address this shortcoming, doorways, common components found in nuclear power plants, were tested to determine their behavior under flooding conditions. Door flooding fragility experiments were performed in the Portal Evaluation Tank, a semi-cylindrical, 7,500-L (2,000-gal) capacity tank. The tank contains a 5.8 ​m² (62.4 ​ft²) square opening for the installation of testable components. The first sets of experiments were conducted using hollow core doors subjected to a water rise scenario. Tank modifications expanded testing capabilities and further testing was conducted, including industrial steel doors. From six hollow core door experiments, the lowest failure water depth was 0.71 ​m (28 in.) and the highest failure water depth was 0.99 ​m (39 in.). From thirteen outward swinging steel door experiments, the average failure depth was 0.9 ​m (35.4 in.) while the highest failure depth for steel doors occurred at 1.07 ​m (42.1 in.). An inward swinging steel door test resulted in a failure depth of 2.05 ​m (80.5 in.). Data collected is being analyzed using Bayesian regression methods to determine parameters of influence, inform future experiments, and generate door fragility curves, which can be integrated into comprehensive risk analysis.