This website is being migrated. In case you don't find the information you are looking for, the old website can be found here. Thank you for reporting any anomalies to communication@ill.eu.

Reactor overview

ILL night large

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.

Contact

Email: reacteur@ill.eu

All pages in the site related to the reactor

Page
Reactor overview
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 app…
Page
Reactor cycles
Reactor startups and shutdowns take place at 8.30 a.m., except on Mondays when they take place at 11.30 a.m. 2026 …
Page
Environnement & Safety
Environnement Environmental monitoring ILL operates a laboratory for monitoring …
Page
Reactor safety FAQ
What are the technical specifications of the ILL’s reactor? The ILL’s high-flux reactor is devoted exclusively to research. It operates continuously during 50-day cycles.Its core co…

Recent news