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Chalk River Laboratories

The Chalk River Laboratories (also known as CRL, Chalk River Labs and formerly the Chalk River Nuclear Laboratories, CRNL) is a Canadian nuclear research facility located near Chalk River, Ontario, about 180 km North-West of Ottawa.

CRL is a site of major research and development to support and advance nuclear technology, in particular CANDU reactor technology. CRL has world-class expertise in physics, metallurgy, chemistry, biology, and engineering and some unique research facilities. For example, Bertram Brockhouse received a Nobel Prize for research carried out at CRL. Chalk River Labs is also a site of production of major quantities of medical radioisotopes. It is a part of Atomic Energy of Canada Limited.



The facility arose out of a 1942 collaboration between British and Canadian nuclear researchers which saw a Montreal research laboratory established under the National Research Council of Canada (NRC). By 1944 the Chalk River Labs were opened and in September, 1945 the facility saw the first nuclear reactor outside of the United States go operational. In 1946, NRC closed the Montreal lab and focused its resources on Chalk River.

In 1952, Atomic Energy of Canada Limited (AECL), was created by the government to promote peaceful use of nuclear energy. AECL also took over operation of Chalk River from the NRC. Throughout the 1950s-2000s various nuclear research reactors have been operated by AECL for production of nuclear material for medical and scientific applications. The Labs produce about half of the world's medical isotopes.

Canada's first nuclear power plant, a partnership between AECL and Hydro-Electric Power Commission of Ontario, went online in 1962 near the site of Chalk River Labs. This reactor, Nuclear Power Demonstration (NPD), was a demonstration of the CANDU design, one of the world's safest and most successful nuclear reactors.

Chalk River was also the site of two nuclear accidents in the 1950s. The first incident occurred in 1952, when there was a power surge and partial loss of coolant in the NRX reactor which resulted in significant damage to the core. Future US president Jimmy Carter, then a US Navy serviceman, was part of the clean up crew. [1][2]

The second accident, in 1958, involved a fuel rupture and fire in the NRU reactor building. Both accidents required a major cleanup effort involving many civilian and military personnel. Follow-up health monitoring of these workers has not revealed any adverse impacts from the two accidents.[3][4] However, the Canadian Coalition for Nuclear Responsibility, an anti-nuclear watchdog group, notes that some cleanup workers who were part of the military contingent assigned to the NRU reactor building unsuccessfully applied for a military disability pension due to health damages.[5]

Chalk River Labs remain an AECL facility to this day and are used as both a research (in partnership with the NRC) and production facility (on behalf of AECL) in support of other Canadian electrical utilities.

2007 shutdown

On November 18, 2007, the National Research Universal Reactor (NRU), which makes medical radioisotopes, was shut down for routine maintenance. This shutdown was extended when AECL decided to connect seismically-qualified emergency power supplies (EPS) to two of the reactor's cooling pumps (in addition to the AC and DC backup power systems already in place), which had been required as part of its August 2006 operating licence issud by the Canadian Nuclear Safety Commission (CNSC). This resulted in a worldwide shortage of radioisotopes for medical treatments because Chalk River makes the majority of the world's supply of radioisotopes, including two-thirds of the world's technetium-99m [6]. On December 11, 2007, the Canadian House of Commons, acting on independent expert advice, passed emergency legislation authorizing the restarting of the NRU reactor and its operation for 120 days (counter to the decision of the CNSC), which was passed by the Senate and received Royal Assent on December 12. Prime Minister Stephen Harper accused the "Liberal-appointed" CNSC for this shutdown which "jeopardized the health and safety of tens of thousands of Canadians". [7] [8] [9] [10]

The NRU reactor was restarted on December 16, 2007.


It has been alleged that the word crud originated as an acronym for Chalk River Unidentified Deposit,[11][12] based on deposits that were discovered to form on early test fuels irradiated at Chalk River Laboratories. However, since etymological dictionaries claim a much older origin for the term (a metathesis form of curd), its association with Chalk River Laboratories was likely a convenient re-construction ("backronym") within the nuclear industry. Nevertheless, this attribution of the word etymology recognizes the contribution of Chalk River Labs to the research on fouling, which continues to be a significant problem in a number of industries.

Some in the nuclear industry have also said that "crud" and its backronym were chosen as a deliberate replacement for nuclear technicians' earliest term for the deposits, which was "Chalk River Activated Products". The deposits had been "activated" (irradiated and transformed from stable isotopes of iron or nickel into radioactive isotopes such as cobalt-60) while suspended in the cooling water (as tiny metallic particles eroded from pipe and valve surfaces) and repeatedly passed through the cooling channels in the reactor core. In fouling technology today, the term "crud" is generally applied to water-borne species which are precursors to solid deposits forming on heat transfer surfaces.

Major facilities

  • ZEEP - Zero Energy Experimental Pile Reactor (1945-1973).
  • NRX - NRX Reactor (1947-1992).
  • NRU - National Research Universal 135 MWt Reactor (1957-).
  • PTR - Pool Test 10 kW Reactor (1957-1990).
  • ZED-2 - Zero Energy Deuterium 200W Reactor (1960-).
  • NPD - Nuclear Power Demonstration 20MW(e) Reactor; located north of CRL in Rolphton, Ontario (1960-1987).
  • SLOWPOKE - Safe Low-Power Kritical Experiment 5 kW Reactor (1970-1976) - moved to the University of Toronto in 1971.
  • TASCC - Tandem Accelerator Superconducting Cyclotron
  • MAPLE-1 - Multipurpose Applied Physics Lattice Experiment Reactor (2000-).
  • MAPLE-2 - Multipurpose Applied Physics Lattice Experiment Reactor (2003-).

See also

  • List of Canadian nuclear generating stations

Further reading

  • Robert Bothwell, "Nucleus. The History of Atomic Energy of Canada Limited", University of Toronto Press, 1988.

  • Chalk River Laboratories is at coordinates 46°03′01″N 77°21′40″W / 46.050242, -77.361002Coordinates: 46°03′01″N 77°21′40″W / 46.050242, -77.361002
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Chalk_River_Laboratories". A list of authors is available in Wikipedia.
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