MNR began operating in April 1959, as the first
university-based
research reactor in the
Commonwealth of Nations, and has been the highest-flux research reactor in
Canada since the closing of the
National Research Universal (NRU) reactor at
Chalk River Laboratories in 2018. The reactor consists of two connected pools; the core can be located and operated in either one. This allows the core to be moved away from experimental apparatus for maintenance. MNR is an example of a reactor where the core is visible while the reactor is operating. The core itself appears to be glowing blue when looked at from the surface, as a result of the
Cherenkov radiation. MNR is the only research reactor in Canada with a full containment structure. The reactor is fuelled with low-
enrichment uranium and cooled and moderated with light water. Heat is transported to the atmosphere through the secondary coolant system via two
cooling towers adjacent to the reactor building. The reactor is used for a variety of purposes: undergraduate education involves NAA (
Neutron Activation Analysis), reactor physics experiments and
radioisotopes for tracers and counting experiments. Graduate studies use neutron beams for
neutron radiography, neutron diffraction, prompt gamma NAA and geochronological techniques. Commercial activities include
radioisotope production and
neutron radiography. The facilities also include a
hot cell and high-activity
cobalt source and high level radioisotope laboratories. Researchers using MNR are based at McMaster as well as other universities in Canada and around the world. The MNR also produces half of the world's supply of
iodine-125, a radioisotope that is used to treat various types of cancer. During the
2009 shutdown of the Chalk River reactor, however, the university increased production of iodine-125 by 20% and offered to retrofit the MNR to handle the production of
molybdenum-99. The MNR had previously handled the production of molybdenum in the 1970s when the Chalk River facilities underwent a vessel replacement. ==Alleged links to terrorism and lawsuit==