The Belgian nuclear research centre SCK•CEN endeavours to develop the new generation reactor MYRRHA. The characteristics that differentiate this technology are the LBE coolant and spallation target, which sustains the fission chain reaction, being it a subcritical reactor. To ensure the safety of this complicated project, some postulated accidental conditions must be considered, to guarantee its safe operation and reduce the probability of such accidents with the appropriate design. In the present work the fluid behaviour in presence of a local internal blockage in a 19-pin wire-wrapped rod bundle representing the MYRRHA fuel assembly is studied. Indeed, through numerical CFD simulations, the hydraulic as well as the thermal fields in presence of both solid and porous blockage are analysed, to tackle fuel assembly safety aspects.