Part 3
Projects & Landmarks
Energy / Project


Multi-purpose hYbrid Research Reactor for High-tech Applications

The very first prototype of multi-purpose hybrid nuclear research reactor for high-tech applications


The Multi-purpose hYbrid Research Reactor for High-tech Applications (MYRRHA) is a first-of-a-kind, innovative nuclear research reactor designed as an Accelerator Driven System (ADS), able to operate in subcritical and critical modes. MYRRHA will demonstrate the ADS concept intended for the efficient treatment of the high level nuclear waste through partitioning & transmutation. It will also fulfil the role of Experimental Technology Pilot Plant (ETPP) in the roadmap for the development of the lead fast reactor (LFR) technology, but its design integrates the function of multi-purpose flexible fast neutron spectrum research reactor (50-100 MWth). Its catalogue of applications includes R&D on the partitioning and transmutation of long-lived radioactive waste, the production of radioisotopes for medical applications and fundamental and applied research in support of the development of fast spectrum reactor and fusion safety and technology.

In the ESFRI Roadmap since 2010, MYRRHA will enter the Implementation Phase in 2019 and is expected to become gradually operational as of 2027.


In the framework of the European Sustainable Nuclear Industrial Initiative (ESNII), a R&D platform aiming to demonstrate Generation-IV Fast Neutron Reactor technologies, MYRRHA has been identified in 2010 as a major facility contributing to the EU’s Strategic Energy Technology Plan (SET plan). Also the Nuclear Physics European Collaboration Committee (NuPECC), whose aim is to promote collaborative ventures between nuclear physicists within Europe, has selected ISOL@MYRRHA to be part of its long-range plan of the top facilities for nuclear physics in Europe.

MYRRHA is designed as a flexible fast spectrum irradiation facility. This means that a fast neutron spectrum is present at every location in the reactor and that every fuel assembly position can be loaded with a driver MOX fuel assembly, a minor actinides fuel experimental assembly, a dedicated experimental rig for material irradiation or medical and industrial radioisotopes production rig. In this way, the entire reactor volume offers possibilities of loading experimental fuel assemblies in conditions similar to the reactor conditions, being a fast neutron spectrum, and in contact with the flowing liquid lead-bismuth at reactor operating temperatures. MYRRHA will also be able to host at least 8 in-pile sections (IPS) (representing a total volume of 8 x 3.700 cm3) with a core-loading pattern optimised to obtain the most appropriate irradiation conditions in the IPS. In this double-walled IPS, a different coolant (Na, NaK, He, H2O) can be present with temperature and pressure conditions optimised for the experimental fuel/material loaded in the IPS. The R&D programme supporting the design of MYRRHA aims at validating solutions on the main design challenges: lead-bismuth liquid metal in reactor conditions, MOX fuel qualification, materials qualification, resilience of innovative components, reactor physics and modelling of fast and sub-critical cores.

steps for implementation

The MYRRHA Preparatory Phase was successfully completed in 2016. The MYRRHA implementation plan involves three phases. The first phase consists in the construction of the 100 MeV accelerator, which is a fully modular infrastructure able to function independently as of 2026-2027, and generating scientific results and revenue. At the end of the first phase, a stage-gate decision is taken whether to proceed with phases 2 and 3 – the development of the accelerator upgrade to 600 MeV and the construction of the reactor – either sequentially, or in parallel.

A legal entity for the construction, the operation and the decommissioning of MYRRHA was identified. The plan is to set up MYRRHA as an AISBL under Belgian law. Important aspects such as the appropriate rules concerning nuclear liability and contractual liability of the MYRRHA consortium and its members were analysed in detail and included in an Intergovernmental Agreement document.

legal status
political support
lead country
prospective member countries
The full list of research institutions involved must be found in the website of the RI
Roadmap Entry
Design Phase
Preparation Phase
Implementation/Construction Phase
Operation Start
estimated costs
capital value
1.616 M€
242 M€
22 M€
1.352 M€
74 M€/year

Belgian Nuclear Research Centre - SCK•CEN
Mol, Belgium