Hydrogen behavior and its control in the KSNPP under severe accident conditions

During a postulated hypothetical severe accident, safeguarding the containment against a potential hydrogen explosion is of paramount importance. As such, accurate prediction of hydrogen generation during hypothetical severe accidents and control measures to limit the concentration of hydrogen in the containment have been important design issues for the Korean Standard nuclear power plant (KSNPP). A realistic model for hydrogen generation was developed using best-estimate methodology and insights from plant-specific probabilistic safety analysis (PSA). Previous studies based on deterministic methodology were reviewed, and overly conservative assumptions and methods were replaced with best-estimate ones consistent with the PSAs.