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).

A leak suspected to have been caused by high cycle thermal fatigue due to fluctuating axial motion of a swirl penetration front end has been detected in early 2018 in a non-isolable Reactor Coolant System branch at the Doel 1 Nuclear Power Plant (Belgium).