Keywords:Reduced order model, Singular value decomposition, Severe accident analysis, RELAP5/SCDAPSIM, SBO
For probabilistic safety margin analysis, we developed a reduced order model (ROM) that reconstruct calculation results of typical severe accident progressions obtained by the severe accident analysis code, RELAP5/SCDAPSIM. In order to construct ROM with minimum calculation costs, an algorithm of efficient data sampling is developed. The ROM is applied to the station black out (SBO) with loss of feed water capabilities. This study shows an efficient method of ROM construction which considers the uncertainties of the RCIC down / recovery time and decay heat.