Atomic Energy of Canada Limited: Encyclopedia II - Atomic Energy of Canada Limited - History

Atomic Energy of Canada Limited - History

Atomic Energy of Canada Limited - 1940s

AECL traces its heritage to the Second World War when a joint Canadian-British nuclear research laboratory was established in Montreal in 1942, under the National Research Council of Canada to develop a design for a nuclear reactor. [1] In 1944, approval was given by the federal government to begin with construction of the ZEEP (Zero Energy Experimental Pile) reactor at the Chalk River Nuclear Laboratories near Chalk River, Ontario, located on the Ottawa River approximately 190 km northwest of Ottawa.

On September 5, 1945 the ZEEP reactor first went critical, achieving the first "self-sustained nuclear reaction outside the United States."[2] ZEEP put Canada at the forefront of nuclear research in the world and was the instigator behind eventual development of the CANDU reactors, ZEEP having operated as a research reactor until the early 1970s.

In 1946 the Montreal research laboratory was closed and research was consolidated at Chalk River Laboratories. On July 22, 1947 the NRX (National Research Experimental) reactor, the most powerful reactor in the world at the time, went critical and was "used successfully for producing radioisotopes, undertaking fuels and materials development work for CANDU reactors, and providing neutrons for physics experiments."[3]

Atomic Energy of Canada Limited - 1950s

In 1952 AECL was formed by the government with a mandate to develop peaceful uses of nuclear energy.

On December 12, 1952 one of the world's first major reactor accidents occurred in the NRX reactor at AECL's Chalk River Laboratories, when a combination of human and mechanical error led to a temporary loss of control over the reactor's power level. Undercooling of the fuel channels led to a partial meltdown. This caused a hydrogen-oxygen explosion inside the calandria. Several fuel bundles experienced melting and ruptured, rendering much of the core interior unusable. The reactor building was contaminated, as well as an area of the Chalk River site, and millions of gallons of radioactive water accumulated in the reactor basement. This water is monitored in shallow trenches not far from the Ottawa River. Hundreds of soldiers were employed in the cleanup and burial of the reactor debris.[4]

The NRX was repaired, upgraded, and returned to service 14 months later and operated for another 40 years, finally being shut down in 1992. Throughout the 1950s the NRX was used by many researchers in the pioneering fields of neutron condensed matter physics, including Dr. Bertram Brockhouse, who shared the 1994 Nobel Prize in Physics for his work in developing the neutron scattering techniques.

On November 3, 1957 the NRU (National Research Universal) reactor first went critical. This is a natural-uranium, heavy-water-moderated and heavy-water-cooled research reactor which is a world-renowned research facility, producing about 60% of the world's supply of molybdenum-99, the principle isotope used for nuclear medical diagnosis. Canada also pioneered use of Cobalt-60 for medical diagnosis in 1951 and currently the NRU reactor produces the medical-use Cobalt-60, while selected CANDU reactors produce industrial-use Cobalt-60, comprising 85% of the world's supply.

On May 24, 1958 the NRU suffered a major accident. A damaged uranium fuel rod caught fire and was torn in two as it was being removed from the core, due to inadequate cooling. The fire was extinguished, but not before releasing a sizeable quantity of radioactive combustion products that contaminated the interior of the reactor building and, to a lesser degree, an area of the surround laboratory site. Over 600 people were employed in the clean-up.[5][6]

A few men were over-exposed to radiation, but no direct injuries resulted from AECL's two accidents.

Atomic Energy of Canada Limited - 1960s

In 1954 AECL partnered with the Hydro-Electric Power Commission of Ontario to build Canada's first nuclear power plant at Rolphton, Ontario, which is 30km upstream from Chalk River. On June 4, 1962 the NPD (Nuclear Power Demonstration) first reactor went critical to demonstrate the CANDU concept, generating about 20 MWe. In 1963, AECL established the Whiteshell Nuclear Research Establishment (now Whiteshell Laboratories) in Pinawa, Manitoba where an organic-cooled and organic-operated research reactor was built.

AECL built a larger CANDU prototype (200 MWe) at Douglas Point on Lake Huron, first going critical on November 15, 1966.

Atomic Energy of Canada Limited - 1970s

In 1971 the first commercial CANDU reactor, Pickering A 1, began commercial operation. By 1973 the other 3 reactors of the A group at Pickering were online and constituted the most powerful nuclear facility in the world at that time.

On May 18, 1974, India detonates a nuclear bomb made from plutonium manufactured by the CIRUS research reactor built by AECL in 1956, which was a commercial version of its NRX research reactor. In addition AECL built two power reactors in all in India based on the Douglas Point design, and many of India's other reactors are domestic variants of this design. The connection between India's nuclear weapons program and its CIRUS research reactor led to a severance of nuclear technological cooperation between Canada and India. [7]

In 1977-1978 the Bruce A group went online and began commercial operation. In 1978, Whiteshell Labs began research into fuel waste disposal.

Atomic Energy of Canada Limited - 1980s

Between 1983-1986 the Pickering B group went online and also in 1983 the single CANDU reactor at Point Lepreau began operation, as did the Gentilly 2 CANDU reactor. Between 1984-1987 the Bruce B group began commercial operation and also in 1987 the CANDU design was ranked one of Canada's top-10 engineering achievements.

Between 1985-1987 a software bug in AECL's Therac-25 medical accelerator caused massive overdoses of radiation on 6 different occasions, with resultant deaths and injuries. In 1987 the machine was found defective by the FDA and recalled by AECL. The software had not been included in the original safety analysis of the machine.

Atomic Energy of Canada Limited - 1990s - present

Between 1990-1993 the 4 CANDU reactors at Darlington went online and represent the most recent reactor construction in Canada.

In 1991, AECL decided to spin-off its medical isotope production business under the name Nordion International Inc. The unit was sold to MDS Health Group and now operates under the name MDS Nordion

With a contract signed in 1991, AECL, in partnership with MDS Nordion, began construction of the MAPLE dedicated isotope-production facility. Constructed on-site at AECL's Chalk River Laboratories this facility will house two reactors and an isotope processing facility. Each reactor is designed to be able to produce at least 100% of the world's medical isotopes, meaning that the second reactor will be used as a back-up to ensure an uninterupptable supply. Although slated to be commissioned in 2000, construction and licensing delays have so far prevented the facility from opening (As of June, 2005)

In 2001, AECL began tests at Chalk River Labs to determine the feasibility of using surplus MOX (mixed oxide) fuel from the Russian and U.S. defence programs (which contains plutonium) as a fuel in CANDU facilities.

Currently, AECL is developing the Advanced CANDU reactor, or "ACR". This design is meant to improve upon the commercial CANDU 6 design in terms of capital cost and construction schedule, while maintaining the classic design and safety characteristics of the CANDU concept.

Adapted from the Wikipedia article "History", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki