D4.2: Analysis of NUSCALE plant with 1D system code and intercomparing between codes

This deliverable presents the work done within Task 4.1 dedicated to the performance of the classic
application of the 1D thermal hydraulic codes to analyse the RPV behaviour under a postulated
transient scenario for NuScale plant. The report contains a brief description of the NuScale reactor.
Based on public data, the different 1D models of the RPV and the core are developed for the TRACE
system code. For transient analysis the boron dilution scenario has been selected. Finally, the results
of the calculations by the different individual models are compared. The exercise showed the users
and code capabilities to model the specified boron dilution transient under typical SMR plant
characteristics as NuScale reactor design although with the limitations of the 1D approximations.
These results can therefore constitute the basis for the development of a more realistic threedimensional
multi-scale approach to be applied in the upcoming tasks.