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Jan10-Editorial-eng.pdf

It took a medical isotope crisis to expose to the Canadian public and to the whole world the troubles of a venerable aging nuclear reactor. Built in 1956, the National Research Universal (NRU) has been a valuable research reactor for decades for the development of the CANDU power plants, but its real source of fame was the pioneering work on neutron scattering which lead to Dr. Bertram Brockhouse’s Nobel Physics prize in 1994, and the production of a significant fraction of the world supply of medical isotopes for cancer diagnosis and treatment.

The fragility of this supply became clear when the head of the Canadian Nuclear Safety Commission Linda Keen shut down the reactor in November 2007. The government’s response was to fire the regulator and force the restart of the reactor with an act of parliament. This was short lived. In May 2009, the reactor closed because of a water leak, and it is still closed at the time of writing this editorial. Weekly updates on the status of its repairs are posted on AECL’s website (www.nrucanada.ca).

As NRU aged there were no plans to replace it. The political and social climates were hostile to anything nuclear. In the mid 90’s a replacement plan emerged which eventually evolved into the ill-fated MAPLE 1 and 2 reactor project whose sole aim was to guarantee the future supply of medical isotopes. It is notable that the other functions of NRU were not included in the plans. The MAPLE reactors were granted an operational license in 1999, and soon after went critical, but problems surfaced, in particular a positive coefficient of reactivity (PCR). Although this should not have been a safety issue, it became one because the design predicted a negative PCR, i.e. a negative feedback effect when the neutron flux is increased. The discrepancy between design and reality created sufficient doubt about the project that the regulators requested more research. In May 2008, the MAPLE project already eight years behind schedule, with significant costs overrun, was cancelled.

The feeling among scientists and stakeholders, in particular the isotope distribution company MDS Nordion, is that the government acted prematurely in shutting down the MAPLEs. No alternate solution was proposed except to extend NRU’s license to 2016.

When, a year later in May 2009, NRU had to shut down because of a water leak, the medical isotope situation became a crisis— a wake-up call that was heard around the world. An expert panel was set up in June 2009 to advise the government “on the most viable options for securing a predictable and reliable supply of the key medical isotope technetium-99m in the medium and long term” [1]. The panel submitted its report in November 2009.

This issue contains the executive summary of the expert report and a series of articles by physicists describing possible solutions using either accelerators [2-4] or a new reactor [5,6]. As a non-expert I will not enter the debate about the merit of the proposals.

When this issue will be read, the government will have announced its plan, which will likely not address the larger issues of the aging NRU. The government’s main concern is the “health” of Canadians; i.e. ensuring the supply of medical isotopes. But, as several authors in this issue argue, research reactors such as the NRU have benefits that go far beyond providing medical isotopes [1,5,6]. They supply neutrons for research and a platform for developing nuclear power technologies.

Little is heard in the press about these other functions of NRU. As Peter Calamai comments in this issue “neutron scattering simply isn’t on the media radar .”[8] Scientists often write that the demise of NRU is depriving the Canadian research community of a valuable tool. But over the years AECL has had other concerns than replacing NRU in a climate hostile to nuclear energy. If we want Canada to be a leader in materials science and a number of leading-edge sciences, including the medical sciences, the scientific community has to build a case for a new nuclear reactor that involves strong support from segments of society other than the physical scientists. We need to find allies. If neutron scattering is so important to industry, one should be able to find support in that sector.

The future of neutron scattering need not rely solely on demonstrating that nuclear reactors are the best source of the currently-used medical isotopes. It is likely that NRU will be back on-line in the spring. It will rise again like a phoenix to extend its remarkable longevity. This will give everyone involved breathing room to plan ahead. The medical isotope crisis is providing increased visibility to nuclear physics that should be capitalized on, as Normand Mousseau argues in his Science Policy column [9].

Living in a more favourable global climate towards the use of nuclear reactors for electricity production, new research reactors are again being built around the world, and this is the time to act in Canada.

1. Executive summary of the Report by the "Expert Panel on Medical Isotope Production", this issue, p. 25-28.
2. Thomas Ruth, "A Short Term Solution to the Medical Isotope Crisis via Direct Production of Tc-99m at Low Energy: A Piece of the Puzzle", this issue, p. 15-16.
3. Randy Kobes et al.,  "Medical Isotope Production Using Commercially-Available Accelerator and Processing Technologies", this issue, p. 17-18.
4. Carl Ross et al., "Using the ¹⁰⁰Mo Photoneutron Reaction to meet Canada's Requirement for ^99mTC", this issue, p. 19-24.
5. Dominic Ryan, "Medical Isotopes and the Future of Neutron Scattering in Canada", this issue, p. 5-9.
6. Richard Florizone and Dean Chapman, "The Canadian Neutron Source: Strenghtening Canada's Isotope Supply and R&D Capacity", this issue, p. 11-14.
7. Zin Tun, "Creating the Future of Chalk River", this issue, p. 29-30
8. Peter Calamai, "Getting Inside Hearts and Minds of Journalists will help Scientists make Better use of the Media", this issue, p. 31-33.
9. Normand Mousseau, Science Policy Corner, this issue, p. 34.

Comments of readers on this editorial are more than welcome.