An updated core design for the multi-purpose irradiation facility MYRRHA

MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) is a multi-purpose re search facility currently being developed at SCK•CEN. It will be able to work in both critical and sub critical modes and, cooled by lead-bismuth eutectic. It will play a key role in the development of the Pb-alloy technology needed for the lead fast reactor GEN IV concept. MYRRHA will demonstrate the Accelerator Driven System (ADS) full concept by coupling a proton accelerator, a spallation target and a sub-critical reactor at a reasonable power level to allow operation feedback. MYRRHA will also contribute to the study of partitioning and transmutation of high-level waste. Recently, a new core design with a longer ac tive core has been proposed. This paper presents the neutronic analyses for this design improvement. The analyses have been done using the MCNP/X code and the in-house developed ALEPH2 depletion code.