Validation and Verification of ASYST Code for Predicting Condensation Phenomena in Nuclear Reactor Safety Systems

Abstract The ASYST (Adaptive System Thermal-Hydraulic) code series is a recent development that integrates the functionalities of SCDAPSIM and SAMPSON. It can simulate and analyze fluid and reactor systems with Best Estimate Plus Uncertainty (BEPU) capability. The proposed work involves conducting a thorough validation and verification process for the ASYST code model to predict the condensation phenomena using a condensation-separate effect test facility (present at the Department of Mechanical and Nuclear Engineering, Khalifa University), specifically focusing on the condensation phase. The condensation separate effect test’s experimental facility was devised by members of the thermal-hydraulic team affiliated with the Nuclear Engineering Department at Khalifa University’s Emirates Nuclear Technology Centre. This apparatus is specifically configured to acquire dependable data on condensation heat transfer analysis in a vertical tube simulating the condensing element within a Passive Containment Cooling System (PCCS), wherein steam and non-condensable gas mixtures are examined. The aim is to provide a detailed description of how the ASYST code aligns with and accurately represents the outcomes of the test facility. The condensation of the separate effect test facility is a critical benchmark for this validation and verification framework. By scrutinizing the code’s performance concerning the test facility outcomes, this approach comprehensively evaluates the ASYST code’s reliability and applicability to practical scenarios of nuclear reactors’ passive safety systems.