MYRRHA (Multipurpose hYbrid Research Reactor for High-tec Applications) is a unique highly innovative prototype of a nuclear reactor driven by a high power linear accelerator. It will be designed to operate in both critical (no accelerator needed) and subcritical mode. MYRRHA has a fast spectrum core cooled by Lead Bismuth Eutectic (LBE) (See Figures 1 and 2).

The primary purpose of MYRRHA is to proof the concept of transmutation of minor actinides. If successful, this process could be implemented at industrial scale allowing for a reduction on the processing and storage time of nuclear waste. Other applications are also envisaged for MYRRHA, such as, the production of new radioisotopes for the treatment of diseases, the testing of materials for nuclear fusion and fission reactors, the provision of operating experience and data for the development of advanced nuclear reactors and the conduct of pioneering research.

The licensing and construction of such an innovative nuclear device is a long-term endeavor. Currently the design is undergoing a pre-licensing phase. Pre-licensing is a process that Belgian prospective licensees can apply for in any project, with the aim of identifying at an early stage barriers to the licensability of the design. The objectives of the pre-licensing process are:

• The identification by the nuclear safety authorities of the necessary improvements to the regulatory framework in relation with the future licensing application.
• The elaboration by the nuclear safety authorities of the safety and security objectives expected from the future facility.
• The review by the nuclear safety authorities of the feasibility and the licensability of the project.
• The description, by the designer, of the safety and security options that apply to the future facility in view of satisfying the minimum objectives expected by the nuclear safety authorities.
• The elaboration, by the designer, of answers and justifications to specific points of attention identified early in the process.

MYRRHA is a very innovative design where the designer is currently undertaking significant R&D programs in order to understand the technological and scientific challenges posed by the innovative design decisions made. Bel V will have to assess the solutions applied to those challenges in terms of safety for the people and the environment, which poses a different challenge. Bel V’s highly qualified engineers and scientists get ready for this challenge by:

• Participating in international forums, such as the OECD/NEA Working Group on the Safety of Advanced Reactors where matters related to the licensing of advanced technology are discussed by regulators from different countries.
• The elaboration of internal topical reports on specific innovative areas with the aim of identifying current knowledge gaps, and the way in which they can be filled by training, R&D or working with experienced partners.
• Bilateral contacts with other regulators to discuss lessons learnt in the application of their respective (pre-)licensing processes to innovative designs.
• Developping experience & competence in computational tools and methods for metal cooled fast reactors.

Ultimately, MYRRHA offers the possibility of training a next generation of engineers and scientists in the nuclear field, together with experienced professionals, by participating from the onset of this project in understanding and working out solutions to the many challenges of licensing advanced nuclear technology.