The ILL high-flux reactor
Under its dome, the ILL operates the world’s most intense continuous neutron source: the High-Flux Reactor (HFR, known officially as Installation Nucléaire de Base n° 67), a nuclear research reactor designed to provide very intense neutron beams. The reactor operates 24 hours a day in cycles of approximately 60 days, delivering three cycles per year. Its core consists of a single fuel element of enriched uranium (almost 10 kg) cooled by heavy water (thermal power 58 megawatts).
Neutrons are produced by the fission of uranium nuclei. They can reach speeds of 20,000 km/second and must be slowed down (or moderated) for use in research. The ILL reactor comprises different sources that allow scientists to select different energy ranges.
The High-Flux Reactor has a modular structure that allows virtually all of its components to be replaced and upgraded. The replacement of the reactor vessel in 1995 has extended the technical life of the HFR until around 2060.
Safety and environment information:
Nuclear transparency and safety: annual report (in French)