Coupled simulations for prismatic gas-cooled reactor

The development and deployment of gas-cooled reactors (GCRs) require flexible modelling simulation tools for a detailed understanding the system behavior in normal operation accidental scenarios. Amongst identified safety-relevant scenarios reactors, outlet plenum flow distribution during operations was ranked to be high importance with low knowledge level phenomenon identification ranking table (PIRT). present paper contributes accurate models using stand-alone coupled codes GCR lower region, which are needed address nuclear reactor safety issues early enough so that delays licensing facility construction can minimized. For first time this paper, an assessment predictive capabilities system-thermalhydraulics CFD against heat transfer measurements prismatic block is reported. mixing experiments integral temperature test at Oregon State University (OSU HTTF) were simulated mode predict mixing. coupled-code analysis used 3D code STAR-CCM + 1D thermalhydraulics RELAP5-3D account system-level feedback on occurring reduced power and/or mass rate. one OSU conditions, existing predicted measured core temperatures reasonably well two different elevations, suggesting available adequate such analysis. Through study, better suitability (TH) gained more prediction GCRs anticipation eventual need perform analyses.