Other CNL Research Reactors

CNL started work on the NRU (National Research Universal) reactor design in 1949. It was built as the successor to the NRX (National Research Experimental) reactor at the Atomic Energy Project of the National Research Council Canada (NRC) at the Chalk River Laboratories. The NRX reactor was the world's greatest source of neutrons when it started operation in 1947 and had attracted a large scientific community that was conducting neutron research for the first time. The scientific community did not know how long a research reactor could be expected to operate so the management of Chalk River Laboratories began planning the NRU reactor to ensure continuity of the research programs.

NRU started self-sustained operation at 6:10 a.m. on November 3, 1957. With that landmark achievement, Canadian science and technology stepped up onto the world stage. At 200 million watts of power, it was a quantum leap forward from its predecessor, the NRX, and once again showcased Canada's Chalk River Laboratories as a world leader.

NRU was the birthplace of many scientific achievements. In 1994, Canadian physicist, Bertram Brockhouse was awarded the Nobel Prize in Physics for his influential work carried out at NRX, then later NRU in the 1950s, using neutron scattering to explore materials. A beam of neutrons can be directed onto a specimen of material, and by measuring how that beam is reflected, scientists can learn a great deal about the structure of the specimen at the atomic level. Using the technique that Brockhouse pioneered, the NRC Canadian Neutron Beam Centre at NRU enabled scientists from across Canada and around the world to investigate new materials with neutrons.

In October 1986, the NRU reactor was recognized as a nuclear historic landmark by the Amercian Nuclear Society.

In May 2007, the NRU reactor set a new record for the production of medical isotopes.

In June 2007, a new neutron scattering instrument was opened in NRU. The D3 Neutron Reflectometer was designed for examining surfaces, thin films and interfaces. The technique of Neutron Reflectometry was relatively new, and capable of providing unique information on materials in the nanometre length scale.

A historical look at research reactors designed by CNL

Since the start-up of our first research reactor in 1945, CNL has designed, developed and built 17 research reactors around the world.

1945 - ZEEP (Zero Energy Experimental Pile)
In 1945, this 10-watt research reactor achieved the first controlled nuclear chain reaction outside the United States. Built at CNL's Laboratories at Chalk River, Ontario, it also provided valuable information on the characteristics of heavy-water-moderated fuel lattices for the reactors to come, including early CANDU commercial power reactors. ZEEP was retired from service in 1970.

1947 - NRX (National Research Experimental)
This 42 MWt research reactor achieved criticality in 1947 and generated the highest neutron flux available anywhere at the time. NRX, which was shut down in 1992, was operated by CNL to develop fuels, materials and nuclear components for power reactors, to produce radioisotopes for medicine and industry, and to generate neutron beams for basic and applied research. Reactors of the NRX design were supplied on a turnkey basis to India in 1960 and Taiwan in 1969.

1957 - PTR (Pool Test Reactor)
This 10 kWt pool-type reactor was built at Chalk River in 1957. It used 93% enriched uranium-aluminum plate-type fuel. The reactor, which was retired from service in 1990, was used for burn up measurement of fissile samples from NRX.

1957 - NRU (National Research Universal)
Designed as a 200 MWt reactor, NRU began operating in 1957 and was retired from service on March 31, 2018. It produced a high percentage of the world's medical and industrial radioisotopes, including molybdenum-99, a critical isotope used for medical diagnoses. NRU's large irradiation space was an important factor in the testing of fuel bundles and fuel-channel components for CANDU reactors. NRU was used for research into reactor fuels, materials and components, and was the centre for neutron beam research in Canada. Originally designed for operation with natural uranium, NRU was converted to high-enriched uranium in 1964. CNL had been operating NRU with low-enriched uranium (LEU) fuel since 1991.

1960 - ZED-2 (Zero Energy Deuterium-2)
This larger version of ZEEP started up in 1960 to facilitate measurements on larger, more representative CANDU lattices. It has also been used for definitive studies of the effects of heavy water and alternative light water and organic coolants. The reactor is still operating at Chalk River where it is used for reactor physics research.

1965 - WR-1 (Whiteshell Reactor-1)
WR-1 was the central experimental facility at CNL's Whiteshell Laboratories in Manitoba, Canada from 1965 to 1985. The WR-1 featured the first CNL-designed calandria fabricated from stainless steel. It also demonstrated the feasibility of an organic-cooled CANDU power reactor.

1968 - SLOWPOKE-2 (Safe Low Power Critical Experiment)
The prototype of this 20 kWt reactor was tested in the PTR pool at Chalk River from 1968-1970. It was designed for neutron activation analysis, trace radioisotope production and as a tool for teaching nuclear science and engineering. It is the only reactor considered safe enough to be licensed for unattended operation. Eight SLOWPOKE reactors have been supplied to universities and research centres across Canada and in Jamaica. Six remain in operation.