Reliability Analysis in Support of Risk Assessment for Hydroelectric Generating Stations

In work sponsored by the U.S. Army Corps of Engineers (USACE), Pacific Northwest Laboratory (PNL), Richland, Wash., has performed a frequency analysis regarding the nonroutine closure of water flow through the turbines of powerhouses along the Columbia and Snake Rivers. The analysis involved developing a frequency analysis model capable of producing frequency profiles of overspeed and flooding events as a function of time and the associated component importance rankings. Data regarding hydropower equipment failures from a previous study were used to estimate component failure rates within the model. The present paper summarizes the model development and quantification, and calculation of component importance measures. The results of this analysis can be used as input to further analyses to evaluate economic consequences of overspeed and flooding events and to provide policy recommendations for operations of hydroelectric generating stations.