Multi-purpose hYbrid Research Reactor for High-tech Applications (MYRRHA) is the flexible experimental accelerator-driven system in development at SCK•CEN. The MYRRHA facility, currently developed with the aid of the FP7-project ‘Central Design Team’ is conceived as a flexible irradiation facility. MYRRHA will allow fuel developments for innovative reactor systems, material developments for GEN IV systems, material developments for fusion reactors, radioisotope production for medical and industrial applications, and Si-doping. MYRRHA will also demonstrate the accelerator-driven system full concept by coupling the three components (accelerator, spallation target and subcritical reactor) at reasonable power level to allow operation feedback, scalable to an industrial demonstrator and allow the study of efficient transmutation of high-level nuclear waste. Because MYRRHA is based on the heavy liquid metal technology, lead–bismuth eutectic, it will be able to significantly contribute to the development of Lead Fast Reactor (LFR) Technology, and in critical mode, MYRRHA will play the role of the European Technology Pilot Plant in the roadmap for LFR. Copyright © 2011 John Wiley & Sons, Ltd.

The BR1 reactor located at the Belgian Nuclear Research Centre SCK·CEN in Mol, Belgium, is a research reactor with a variety of irradiation possibilities. Thanks to its large reactor core, its flexible operation and its different irradiation facilities, this reactor is particularly suited for in-core and ex-core neutron physics experiments and industrial applications. As an MCNP model of the BR1 reactor exists, the experimental work can be supported by MCNP calculations if required.

In order to provide an appropriate level of energy to the whole world, nuclear energy is still going to play an important role. Nuclear energy can help reducing the CO₂ emissions, which today are excessive. The problematics of nuclear waste can be solved using long-term geological storage in deep suitable formations. Partitioning and transmutation can help reducing the radiotoxicity of spent fuel to more acceptable durations of time. The MYRRHA project investigates since more than 20 years the possibility to demonstrate transmutation at a reasonable power level. In this paper we present the current state of the MYRRHA reactor design and the associated research and development activities.