Nationally Sourced Reactor Fuel
The distinguishing benefit of Canada’s CANDU reactor technology is its ability to use natural uranium or uranium enriched less than is necessary for light water reactor fuel, making fuel acquisition, preparation, and handling safer and less expensive.
Critical to any proposed nuclear plant is a reliable, long-term supply of uranium to fuel the reactor. Currently, the world’s known recoverable uranium resources equal 4.7 million tonnes, half of which are found in Canada. Canada produces about one-third of the world’s uranium, placing it far ahead of Australia (23%) and Kazakhstan (10%). As an added benefit, Canada’s uranium is up to two orders of magnitude higher in quality than all other worldwide deposits.
All uranium mining activities are located in northern Saskatchewan. Saskatchewan’s center-right Saskatchewan Party government, which gained the majority in 2007, has actively encouraged and supported uranium mining in the province. This reversed a New Democratic Party policy that was established in the early 1990s to phase out uranium mining. The new government recognized that the jobs and benefits to the provincial economy from uranium mining were far too important to be eliminated by boycotting uranium mining and that the environmental impact of the mining could minimized.
Cameco operates the McArthur River mine, the world’s largest uranium mine (Figure 6). McArthur River started production in late 1999 and is known to have enormous high-grade reserves. Areva Resources operates the McClean Lake Mine, which also started production in mid-1999. Both McClean Lake and McArthur River mines have achieved ISO 14001 environmental certification.
6. Uranium strike. Located in northern Saskatchewan, the McArthur River mine has the world’s largest, high-grade uranium deposit. Courtesy: Cameco
Uranium, in the form of yellowcake (U 3 O 8), is trucked from Saskatchewan milling operations to the world’s largest uranium refinery in Ontario. The yellowcake is refined to remove impurities and is converted into uranium trioxide (UO 3) in a multistep chemical and physical process using solvent extraction. Most of the UO 3 is converted into uranium dioxide (UO 2) for use as natural uranium in existing CANDU reactors.
Because of the CANDU reactor technology, Canada does not have to enrich uranium. CANDU fuel bundles contain either 28 or 37 rods of tubular zirconium alloy sheaths with UO 2 pellets inside, each rod being about 50 cm long (Figure 7).
7. Bundle of energy. A fuel bundle used to generate electricity in CANDU reactors. Courtesy:Cameco
The UO 3 can also be converted into uranium hexafluoride (UF 6) for export and subsequent enrichment and conversion to UO 2 for use in light water reactors. Natural uranium contains 0.7% uranium-235 (U-235), the uranium isotope of interest. Enrichment increases U-235 content to the 3% to 5% range required for light water reactors. Each year, 15% to 20% of Canada’s uranium production is consumed domestically; the rest is exported to other countries that use light water reactors.
Managing Used Nuclear Fuel
In Canada, used nuclear fuel (UNF), defined as irradiated fuel bundles that are removed from operating nuclear reactors, is safely stored at licensed facilities located in Ontario, Québec, New Brunswick, and Manitoba. After UNF is removed from a reactor, it is placed in wet storage for seven to 10 years, during which time its heat and radioactivity are reduced through the radioactive decay process. The UNF is then placed into dry-storage containers. Although the design life of a dry-storage container is 50 years, its expected life is 100 years or longer, and it provides an acceptable option for interim storage. (See "How to Solve the Used Nuclear Fuel Storage Problem," POWER, August 2008 and "Patchy Progress in Europe with Radioactive Waste Management," January 2009.)
In 2002, the Canadian government passed the Nuclear Fuel Waste Act and established a Nuclear Waste Management Organization (NWMO) comprising utility representatives from OPG, Hydro-Québec, and New Brunswick Power Corp. Oversight of the NWMO is provided by Natural Resources Canada. The objective of the NWMO was to investigate and recommend the best options for long-term UNF management to the federal government.
The NWMO engaged interested Canadians, stakeholders, and specialists in a three-year study and reviewed the benefits, risks, and costs of three technical options:
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Deep geological disposal in the Canadian Shield.
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UNF storage at nuclear reactor sites.
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Centralized UNF storage, either above or below ground.
In November 2005, the NWMO released its final study on "The Future Management of Canada’s Used Nuclear Fuel," which was sent to the Government of Canada as part of Canada’s long-term plan for UNF management. The study concluded that a process called Adaptive Phased Management be used for long-term UNF management.
The approach offers to maintain UNF at reactor sites in Ontario (at Bruce, Pickering, and Darlington Nuclear Power Stations and Chalk River Laboratories), Québec (Gentilly Nuclear Power Station), New Brunswick (Point Lepreau Nuclear Power Station), and Manitoba (Whiteshell Laboratories, a nuclear site undergoing decommissioning), while preparing for storage in a deep geologic repository.
Furthermore, the report proposed that centralized facilities should be in the provinces that have benefited from the nuclear fuel cycle. This includes the three that generate electricity from nuclear power as well as Saskatchewan, which has benefited economically from the uranium mining industry.
Deep geological storage involves storing UNF underground in the Canadian Shield, relying on natural and engineered barriers to isolate UNF from the environment over the material’s radiological lifetime.
Another big advantage: UNF could be removed in the future for reprocessing. For example, a single CANDU-6 fuel bundle can be reprocessed multiple times, with the final high-level waste product the size of a golf ball, or 0.5% the size of the original fuel bundle.
New Build Submissions
In August 2006, Bruce Power applied for a license with the CNSC to prepare a site for construction of up to four new reactors at its Bruce County facility in Ontario following the completion of a two-year feasibility study. The CNSC, much like the Nuclear Regulatory Commission in the U.S., is the agency that establishes health, safety, security, and environmental standards for the regulation of nuclear power reactors.
The CNSC accepted the company’s project description for a 4,000-MW project at the end of January 2007. In order to expedite its environmental assessment, it recommended to the federal environment minister that the project go straight to a public review panel rather than first negotiating an eight-month process to determine if such a panel were necessary.
Bruce Power submitted its environmental impact statement to the government in September 2008, showing that the project would not have significant environmental impacts. Depending on the construction start dates, the new plants are expected to come online between 2014 and 2018. Six different reactor types are under consideration.
In September 2006, OPG followed suit and applied for a license to prepare its Darlington site for construction of up to four new reactors and submitted a project description to the CNSC in April 2007. Applications from interested companies — AECL, AREVA, and Westinghouse — were submitted in February 2009 and are being assessed by Infrastructure Ontario with representatives from the Energy and Finance ministries, Bruce Power, and OPG. A decision, expected in June 2009, will be based on the lifetime cost of power, schedule, and investment in Ontario. The reactors, yielding a total of 2,000 to 3,500 MW, are expected to come online in 2018.
New build applications are even expanding into provinces such as Alberta that have traditionally used fossil fuels for electricity production. A current proposal by Bruce Power Alberta is to construct up to 4,000 MW from twin ACR-1000 reactors at Peace River costing up to C$10 billion. Energy Alberta Corp. has also applied to the CNSC for a site license for a C$6.2 billion 2,200-MW plant aiming for a 2017 start-up date.
Though a nuclear renaissance remains just beyond the horizon for the U.S., it appears to be in full flower in Canada.
—James M. Hylko (jhylko1@msn.com) is a POWER contributing editor.
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