Study on partial blockage in an LMR 19 pin bundle subassembly

It is important to know the effect of a local flow blockage on the potential of localized boiling and a failure of the fuel cladding within an LMR fuel subassembly. In this study, flow blockage is simulated by using the subchannel analysis codes, MATRA-LMR and SABRE4 with THORS experimental data of ORNL. Both codes show relatively good agreement to the experimental data for exit temperatures in no blockage case. But in blockage case, there were some differences between the experimental data and the code calculational results. Solid blockage could not be exactly predicted by MATRA-LMR because of the numerical instabilities of this code