HFR Petten

The High Flux Reactor at Petten, on the coast of North Holland, is a tank-in-pool MTR-type reactor, cooled and moderated by light water, owned by the European Commission's Joint Research Centre and operated by NRG. It reached criticality on November 9, 1961 and its power was raised in steps to 45 MW by 1970. It was born to test materials and fuels for the European nuclear industry, and over the years its use shifted toward radioisotope production and basic research; it also has a beam channel adapted for boron neutron capture therapy.

Together with BR2 in Belgium, it is one of the pillars of the world's molybdenum-99 supply: around 2010 it covered 60% of European demand for medical isotopes, and NRG puts it at 30% of world production, raw material for 30,000 patients a day. Its fragility was also exposed: the shutdown for corrosion in the cooling circuit between August 2008 and February 2009 caused a worldwide technetium-99m shortage. It converted its fuel from highly enriched to low-enriched uranium in 2006 and dropped HEU targets for isotopes in January 2018. It is expected to run until 2030, when the PALLAS reactor, under construction on the same site with INVAP's participation, replaces it.