Dynamic Probabilistic Risk Assessment Based Response Surface Approach for FLEX and Accident Tolerant Fuels for Medium Break LOCA Spectrum

After the Fukushima Daiichi Accident, safety features such as accident tolerant fuel (ATF) and diverse flexible coping strategies (FLEX) for existing nuclear fleets are being investigated by US Department of Energy under Light Water Reactor Sustainability Program. This research is conducted to quantify risk-benefit these features. Dynamic probabilistic risk assessment (DPRA)-based response-surface approach has been presented FLEX ATF benefits estimating associated with each option. ATFs multilayered silicon carbide (SiC), iron-chromium-aluminum, chromium-coated zirconium cladding were considered in this study. While candidates perform better than current (Zr), they may introduce additional failure modes some operating conditions. The analysis modules (FAMs) developed investigate performance. dynamic assessments performed using RAVEN, a DPRA tool, coupled RELAP5 FAMs. A cumulative distribution function-based index provided mean comparing enhancements. For medium break loss coolant accidents, operational timing window type was estimated. Among candidates, SiC-type most beneficial candidate an increased margin Zr-based found complement terms time.