The Beam Ports in Action

By 1960, instrumentation had been brought into the containment building for use in conjunction with the beams of neutrons that are extracted by the beam tubes. Experiments in neutron spectrometry and neutron diffraction were soon underway.

The View from the Bottom of the Pool

Meanwhile, on the other side of the wall, the control rods were put into place, and photographed from the floor of the reactor pool (on level with the beam port floor).

The Bottom of the Pool: the Reactor Core

Here, the core of the nuclear reactor – where the self-sustaining chain reaction of uranium-235 takes place – is fitted on to the floor of the reactor pool at a depth of 15.2 m below the main (“Experimental”) floor of the building.

The Core: Viewed from Above

An alternate view of the reactor core taken from the top of the pool (the Experimental Floor). From this angle, three beam tubes are clearly visible radiating outwards from the reactor core, along with two unoccupied beam ports.

The Experimental Floor

At pool level (on the Experimental Floor), a support bridge crossing the  pool is visible, as well as the overhead crane that was shown earlier. Across the pool on the left lies the Control Room, where reactor operations are monitored. Above the Control Room, a row of offices overlooks the Experimental Floor.

The Control Room

The state-of-the-art control room was soon completed and ready for occupancy, with the McMaster Nuclear Reactor first achieving criticality (i.e. a self-sustaining nuclear chain reaction) at 00:36 h on April 4^th, 1959.

The Opening Ceremony

On April 10, 1959, a ceremony was held to officially open the McMaster Nuclear Reactor, the first university-based nuclear reactor in the British Commonwealth. Among the attendees was John Diefenbaker, the Prime Minister of Canada at that time.

The Reactor Today

More than 50 years later, MNR continues to operate five days per week, providing  an invaluable source of neutrons for research scientists, performing service irradiations for a number of industries, and generating medical isotopes for cancer therapy.