Preliminary Assessment of CATHARE-MODELICA Codes Coupling for Safety Analyses in Nuclear Cogeneration

To assure a viable energy transition towards a low-carbon future energy mix, Small Modular Reactors have gained attention in the last years due to their peculiarities, e.g., potential enhanced safety, economic viability due to series production, ease of installation and modularity. Moreover, their implementation in Hybrid Energy Systems in cogeneration operation could bring to the decarbonization of other carbon-emitter industrial sectors. However, the introduction of Small Modular Reactors in Hybrid Energy Systems for cogeneration can result in different transients induced by the thermal users on the nuclear power plant, which must be carefully considered when performing a safety assessment. To this purpose, the paper describes the methodology adopted to perform a code coupling useful for future safety analyses of these hybrid energy systems. In particular, the coupling is performed between a well-assessed thermal hydraulic system code used to perform nuclear safety analyses, namely CATHARE 3, and a widely-adopted a-causal dynamic modelling language, namely MODELICA, exploiting the features of both modelling codes. The results, although preliminary, show good coupling capabilities between the two codes, providing an excellent starting point to perform future analyses of some transients induced on nuclear systems in cogeneration mode.