Coupled reactor physics and thermal-hydraulics analysis of an SCW-SMR reactor concept – Part I: Model development and demonstration

• An SWC-SMR Apros model was developed using hot, cold and average coolant channels. • An SCW-SMR Serpent model was developed using temperatures and densities from Apros. • A semi-automated coupling method between Apros and Serpent was developed. • The steady-state behaviour of the SCW-SMR concept was evaluated in detail. • The advantages of the SCW-SMR concept over the HPLWR design were demonstrated. In the frame of the EU ECC-SMART project, the pre-conceptual design of a water-cooled small modular reactor operating at supercritical pressure (SCW-SMR) with seven heat-up stages is under development and assessment. BME is participating in this project as a consortium member and is developing several models and coupled code systems to investigate the features and characteristics of the proposed new concept. This first part of the two-part paper presents the concept design, and the models developed in the Apros thermal-hydraulics system code and the Serpent 2 Monte Carlo reactor physics code. The developed coupling methodology of these models is also described in detail. Finally, the first coupled calculation results, obtained using two different core enrichment maps, are presented and compared. The behaviour of the seven heat-up stages and the power and temperature distributions of the core are evaluated in detail.