RISK ASSESSMENT FOR SPENT-FUEL POOL COOLING AT BOILING WATER-REACTORS

A risk assessment of potential events at Susquehanna Steam Electric St ation (SSES) is described wherein a loss of cooling occurs in a spent- fuel pool (SFP). This evaluation was performed as part of the evaluati on of potential generic issue 93-01, regarding the safety impact of in cidents involving the loss of SFP cooling (SFPC). The analysis investi gates allegations and concerns identified in a Title IO, Part 21 Code of Federal Regulations (IO CFR 21) report filed by two former contract employees, who alleged that SSES has design deficiencies associated w ith SFPC that make it susceptible to unsafe conditions. The evaluation estimates the likelihood of a loss-of-SFPC event at SSES and the asso ciated probability of the SFP heating up to near-boiling conditions. T he evaluation also includes an assessment for such near-boiling events for their contribution to core damage and an estimate of order-of mag nitude core damage frequency. The analysis addresses SSES plant condit ions that existed prior to the IO CFR 21 report and also current plant conditions. Data for this analysis were obtained from the SSES licens ee and from other relevant data sources, including probabilistic risk assessment information. Background for the evaluations performed, the methodology used in the evaluation, the data and modeling used for the analyses, the analysis techniques and results, and conclusions are pr esented.