Canada has been generally supportive of minimization of highly enriched uranium (HEU) but does not appear to have an articulated and coordinated policy on the issue. While Canada's Atomic Energy of Canada Limited (AECL) has converted or is in the process of converting the nuclear fuel in its research reactors from highly enriched uranium (HEU) to low-enriched uranium (LEU), it continues to employ HEU "targets" for the production of medical isotopes in its National Research Universal (NRU) reactor at Chalk River Laboratories in Ontario.

Overview

Canada is a non-nuclear weapons state signatory to the Nuclear Non-Proliferation Treaty (NPT), and thus its entire declared stockpile of highly enriched uranium is civilian-use and its facilities are all subject to IAEA safeguards. There are, however, no public Canadian declarations of HEU holdings. Unlike several other states, Canada does not provide this information to the International Atomic Energy Agency (IAEA) as part of an annual declaration of plutonium stocks (INFCIRC/549).[1]

Canada has HEU in the form of nuclear fuel, HEU targets for the production of medical isotopes, as well as HEU scraps from target fabrication. It has converted and/or plans to convert or decommission all of its research reactors.[2] Three reactors currently continue to use HEU in their cores.[3] Medical isotope production at the NRU reactor involves the irradiation of 93% enriched uranium targets; after this short irradiation period, they are typically still at a 90% enrichment level. Discharged targets are stored in a fissile solution storage tank or as concretized waste.

Canada does not have domestic enrichment capabilities at present, nor are there current plans to create a capability to produce HEU. It uses HEU imported from the United States (exports licensed by the U.S. Nuclear Regulatory Commission). According to one estimate, of 2,169 kilograms (kg) of HEU sent from the United States to Canada through 1992, approximately 1,184 had been repatriated to the United States. Additional 16 kg and 20 kg shipments were returned, leaving approximately 1,229 kg of U.S.-origin HEU in Canada.[4] Repatriation of some of this HEU inventory has been ongoing since 2010, in line with Canada's Nuclear Security Summit commitments.

Conversion and Shutdown of HEU-Fueled Reactors and Reactor Projects

Canada is in the process of converting its Slowpoke (Safe Low-Power Critical Experiment) reactors in Alberta and Saskatchewan to LEU fuels, and is decommissioning the reactor in Halifax.[5] It has already converted the MNR pool reactor at McMaster University, the Slowpoke reactor in Montreal, and the NRU reactor at Chalk River (in 1993).

Canada has shut down its NRX heavy water reactor (in 1993), and the Slowpoke reactors PTR (1990), at Kanata (1989), Ottawa (1984), and Toronto (1998), all of which employed HEU fuel. In August 2011, the United States joined Canada in converting Jamaica’s Slowpoke reactor in Kingston.

Radioisotope Production

Canadian company Nordion is the world's leading producer of the radioisotope molybdenum-99 (Mo-99), which has a 2.7-day half-life and decays to 6-hour half-life technetium-99m, a gamma ray emitter widely used in cancer, heart disease and brain disorder treatment.[6] It is the United States’ main supplier of medical isotopes.

There are, however, concerns associated with the degree to which patients worldwide rely upon a 50-year old reactor, the NRU, for the production of Mo-99. In addition, in May 2008, construction of the reactors (Multipurpose Applied Physics Lattice Experiment or MAPLE) intended to replace the NRU was cancelled.

National Research Universal (NRU) Reactor

Mo-99 has been produced since the late 1950s in the AECL's NRU reactor at Chalk River, using uranium targets fabricated from HEU supplied by the United States. NRU produces about one-third of the world’s supply of medical isotopes. In August 2006, Canada's nuclear regulator, the Canadian Nuclear Safety Commission (CNSC), extended the NRU's operating license until 2011, provided certain safety upgrades were completed. After this license renewal, a scheduled maintenance shutdown in November 2007 was extended when CNSC officials discovered that safety upgrades mandated in 2006 had not been completed.[8] The delay in start-up and the resulting shortfall in isotope production triggered a political firestorm. The head of the CNSC, who would not authorize the restart without completion of the upgrades, was demoted and the NRU was given permission to start up without the safety upgrade by emergency legislation (Bill C-38) passed by Canada's House of Commons.

The NRU was restarted for isotope production on December 16, 2007. The CNSC resumed full regulatory oversight of the reactor only after the safety upgrades were completed in April 2008.[9]

The NRU faced trouble again in May 2009, when a heavy water leak shut down the reactor for fifteen months. The shutdown again led to a global shortage of medical isotopes and angered distributors, who lacked adequate back-up suppliers to counteract the failure of the NRU. [10] In November 2011, the reactor's operating license was extended through 2016, when the NRU is scheduled for shutdown. Distributors, such as MDS Nordion, have continued to look elsewhere for supplies of medical isotopes. Canada, for its part, has hoped to rectify the unreliability of the reactor by pursuing new reactors and new radioisotope production methods.

Multipurpose Applied Physics Lattice Experiment (MAPLE) Reactors

In the mid-1990s, Canada developed a plan to replace the NRU with a new reactor type, designated MAPLE (for Multipurpose Applied Physics Lattice Experiment). Eventually, two new reactors, MAPLE 1 and 2, were planned, along with a New Processing Facility (NPF). Originally, the MAPLEs were supposed to go online in 1999 and 2000. However, the project faced multiple delays due to technical problems, and failed to obtain an operating license.

In May 2008, AECL decided to halt construction of the reactors due to "costs of further development, as well as the time frame and risks involved." [11] In addition, concerns about "continued commercial viability" of medical isotopes from HEU reportedly also figured in AECL's decision to scrap the MAPLEs. [12] MDS Nordion, the Canadian isotope supplier, argued that it was "not consulted" by the AECL on this decision, though AECL committed to work with the company to ensure isotope supply after 2011, when the NRU's operating license was initially set to expire. [13] In July 2008, Nordion filed a lawsuit against AECL, stating that it was "disappointed that AECL and the Canadian Government decided to abandon the MAPLE project without establishing a clear plan for the long-term [radioisotope] supply." [14] After lengthy arbitration proceedings concluded in September 2012, Nordion announced that it was not successful in its claim for monetary damages resulting from AECL's decision on the MAPLE project.[15]

It should be noted that the U.S. exported 45 kg of HEU for use in the MAPLEs. [16] Though the reactors have been cancelled, no statements have been made to date on whether or not this HEU will be returned to the United States, and the issue was left out of the commitments Canada made during the 2010 and 2012 Nuclear Security Summits.[17]

Conversion of Radioisotope Production

Pursuant to then-U.S. law regarding the export of HEU, the U.S. 1992 Schumer Amendment, MDS Nordion agreed in the late 1990s to undertake a development program to convert from HEU to LEU targets in order to remain eligible for HEU exports from the United States. According to scientists involved in the RERTR program at Argonne National Laboratory, Nordion was particularly cooperative with the program each time it was applying for a new license to import U.S. HEU. [18]

In 2003, however, Nordion concluded that conversion was not feasible without a significant interruption in production and that the new processing facility, which had already been constructed, could not handle LEU targets (despite initial plans to build a facility that could be converted to handle LEU). Thus, construction of a new processing facility would be required, entailing unacceptable costs in the view of the Canadian producer ($90 million Canadian). This led the company to further curtail cooperation with the RERTR program, focusing instead on seeking relief from the law imposing restrictions on U.S. transfers of HEU and ensuring continued exports to Canada.

An amendment to this end was promoted by Senator Burr and passed as part of the Energy Bill signed into law in August 2005. [19] Under this law, U.S. HEU could be exported to medical isotope producers in Europe and Canada (though not elsewhere) without the condition of agreeing to convert to LEU. The law also required a National Academy of Sciences (NAS) study into the feasibility of producing Mo-99 using LEU. Nordion has participated in this study, maintaining that conversion is possible, though it would take seven to ten years and would be quite costly. [20] In contrast, European producers of medical isotopes have begun conversion to both LEU fuel and LEU targets.

In April 2009, Nordion announced that it would partner with Canada's national laboratory for particle and nuclear physics, TRIUMF, to conduct a joint feasibility study on "producing a viable and reliable supply" of photo-fission produced Mo-99. "Medical isotopes produced using photo fission employ the use of a linear accelerator rather than a nuclear reactor; as such, the need to ship and handle highly enriched uranium is eliminated in favour of naturally occurring uranium," a Nordion release stated.

In September 2010, Nordion took further steps to hedge against potential isotope shortages by inking a deal with Russia to import HEU-based Mo-99 isotopes. JSC Isotope, a subsidiary of Russia's Rosatom, will provide the isotopes during periodic maintenance shutdowns of NRU, and will allow Nordion to circumvent U.S. export laws in the event that the U.S. attempts to return to the standard set by the Schumer Amendment. [21] However, a Nordion spokesperson has indicated that the deal with Russia includes provisions for conducting research and development on HEU-to-LEU conversion projects.

Policy Issues

Canada is a leading advocate of nonproliferation. It played a leading role in promoting the indefinite extension of the NPT in 1995; is a strong proponent of the CTBT and of a (verifiable) FMCT; was a founding member of the Nuclear Suppliers Group and a strong advocate of significant export controls; hosted and promotes the G8 Kananaskis meeting that established the agenda for the G8 global partnership against the spread of weapons and materials of mass destruction; supports the PSI initiative as an important response to the challenges posed by proliferation; and is a proponent of UNSC Resolution 1540.

Canada has also been a partner nation in the Global Initiative to Combat Nuclear Terrorism since its establishment in 2006. In a joint statement issued by the Initiative chairs after its third annual meeting in Astana, Kazakhstan in 2007, the key Initiative priorities included "minimizing the use of highly enriched uranium and plutonium in civilian facilities and activities." However, the Global Initiative has yet to develop plans or agreements to make this commitment concrete.

At the 2010 and 2012 Nuclear Security Summits, Canada made several commitments to securing its fissile material stocks, and has generally fulfilled these commitments in good faith. It will continue to return spent HEU fuel to the United States through 2018, having completed the first shipment of fuel in 2010.[22] Canada has advocated for the extension of the G8 Global Partnership past its 2012 mandate, assisted Mexico with the conversion of its TRIGA Mark III reactor to low-enriched uranium fuel, and hosted a workshop on nuclear industry best practices for the World Institute of Nuclear Security. Canada also has worked with the United States and its Global Threat Reduction Initiative on repatriating HEU from Mexico and Vietnam. [23]

Despite its support of global nonproliferation initiatives, Canada has yet to commit to a position on pursuing efforts to end its use of HEU for radioisotope production, despite its 2005 pledge to end the use of HEU in reactor fuel as part of the North American Security and Prosperity Partnership. Canada has made no concrete steps toward changing its industry, and continues to allow suppliers wide latitude in perpetuating the production of HEU-based medical isotopes. It appears that economic concerns and fears of further isotope shortages continue to slow progress. Canada’s effective subsidization of its HEU-based medical isotope industry exerts downward pressure on prices, inhibits competition from other producers that have begun conversion to LEU-based isotopes, and crowds out new entrants to the industry. Because of these constraints, many companies worldwide are not moving forward on planned LEU-based isotope projects, and the global nuclear industry runs the risk of being unable to reverse a shortfall in medical isotope supply that may result from the 2016 shutdown of NRU.[24] As this date approaches, Canada is likely to face pressure from distributors to renew NRU’s license, and to continue the well-established HEU-based production process in order to prevent further shortages.

The lack of a strong position on HEU minimization on the part of the Canadian government, its complicity in bolstering the current HEU-based production process for medical isotopes, and private sector efforts to extend HEU-based production have led to a weakening of the position of proponents of HEU minimization. As a major supplier of medical radioisotopes, Canada maintains much responsibility for advancing HEU minimization efforts. Until its government lends stronger political support and leadership to HEU minimization, alters its business environment to encourage fair competition from producers who use LEU, pursues serious security initiatives with Russia that preclude arrangements like the 2010 deal with Nordion, and initiates efforts to end the use of HEU in the domestic production of medical isotopes, consolidating a global norm against HEU minimization will continue to be difficult.

Sources:
[1] The nine countries that report their holdings to the IAEA annually as part of INFCIRC/549 are major holders of separated plutonium.
[2] "University Environmental Health and Safety Committee Report to DPMG: June 2008," http://professionalandmanagerialgroup.dal.ca.
[3] See International Panel on Fissile Materials, Fissile Materials Report 2010, p. 143.
[4] Frank von Hippel estimated based on data in NRC reports that 1,229 kg of U.S.-origin HEU remained in Canada (2,169–1,184–16+20) before the repatriations of the NRU/NRX fuel began after the Nuclear Security Summit.
[5] On the decommissioning, see Canadian Nuclear Safety Commission, "Nuclear Research," CNSC website, updated 06 June 2012, nuclearsafety.gc.ca.
[6] For additional information on isotope production, see Cristina Hansell, "Nuclear Medicine's Double Hazard: Imperiled Treatment and the Risk of Terrorism," Nonproliferation Review, July 2008, 15/2, pp. 185-208.
[7] For example, risks or reliance on a single isotope were highlighted by a 1991 strike at a Canadian plant that processed Mo-99.
[8] Canadian Nuclear Safety Commission (CNSC), "NRU Reactor Events," August 1, 2008, www.nuclearsafety.gc.ca.
[9] CNSC, "CNSC resumes full regulatory oversight of NRU reactor," April 10, 2008, www.nuclearsafety.gc.ca.
[10] Canadian Press, “New MDS CEO says company is securing several new sources of medical isotopes,” New Glasgow Newspaper, 12 January 2010, www.ngnews.ca.
[11] Atomic Energy of Canada Limited, "AECL to Discontinue Development of the MAPLE Reactors," May 16, 2008, www.aecl.ca.
[12] Daniel Horner, "Questions about future of HEU had role in Maple's end," Inside NRC, May 26, 2008, pp. 4-5.
[13] MDS Nordion, "MDS Responds to AECL and Government of Canada Announcements Regarding Maple Project," May 16, 2008, www.mds.nordion.com.
[14] MSD Nordion, "MDS Commences Arbitration against AECL over Cancelled MAPLE Project and Files $1.6 Billion Court Claim against AECL and the Government of Canada," July 9, 2008, www.mds.nordion.com.
[15] "Nordion announces decision in arbitration with AECL over cancelled MAPLE project," MDS Nordion medical isotopes update, September 10, 2012, www.nordion.com.
[16] Daniel Horner, "Questions about future of HEU had role in Maple's end," Inside NRC, May 26, 2008, pp. 4-5. In addition, the U.S. NNSA contractually committed in 2004 to supply Canada's AECL with 1,500 kg of uranium enriched to 19.75 percent (i.e. LEU) for use as fuel in reactors at Chalk River Laboratories (NRU and MAPLEs). As of August 2008, approximately 1,136 kg have been supplied, 224 kg of which were U-235. The shipments are expected to be completed by the end of 2008. See "Y-12 close to fulfilling isotopes contract," Nuclear Weapons and Materials Monitor, August 4, 2008, pg. 12.
[17] For a discussion of the status of the HEU targets for the MAPLEs, please see Ian MacLeod, "How to solve a problem like 45kg of bomb-grade uranium?" Ottawa Citizen, September 5, 2008, www.canada.com.
[18] For more details on Nordion's cooperation with RERTR, see: George Vandegrift, ''ANL (GFV) Perspective on Conversion of Mo-99 Production from High- to Low-Enriched Uranium," presentation for the National Academy of Sciences study on the production of medical isotopes without HEU, mandated by Section 630 of the Energy Policy Act of 2005, Argonne National Laboratory, http://dels.nas.edu.
[19] For details about Nordion lobbying and the Burr Amendment, see Alan Kuperman, "Bomb-Grade Bazaar," Bulletin of the Atomic Scientists, March/April 2006, pp. 44-50.
[20] For information on recent discussions about converting Mo-99 production, see Ann MacLachlan, "NRG to Study Potential for Use of LEU for Mo-99," NuclearFuel, December 17, 2007, p. 1, and "Nuclear Medicine's Double Hazard."
[21] “MDS Nordion to get medical isotopes from Russia,” CBC News, 23 September 2010, www.cbc.ca.
[22] "Expansion of agreement for the repatriation of highly enriched uranium to the United States," Canadian Nuclear Safety Commission press release, 27 March 2012, nuclearsafety.gc.ca.
[23] Robert Golan-Vilella, Michelle Marchesano, and Sarah Williams, "The 2010 Nuclear Security Summit: A Status Update," Arms Control Associate and the Partnership for Global Security, April 2011.
[24] Miles Pomper, "HEU Minimization after the Nuclear Security Summit," paper presented at the 2012 International Nuclear Materials Management Conference in Orlando, Florida, July 2012.