The international nuclear industry continued critical coverage in August of AECL’s dangerously incompetent handling of their failed Chalk River isotope production reactors NRU and Maple.

Canadian correspondent David Mosey of Nuclear Engineering International revealed a fundamental weakness in AECL’s design for its pair of Maple reactors at Chalk River, located 150 kilometers west of Ottawa on the Ontario side of the Ottawa River. In "Maple cancelled: The first reactors in the world to be dedicated exclusively to medical isotope production have been cancelled," Mosey claimed: "The delay in bringing the Maple reactors into service was principally the result of the discovery that the reactors’ power coefficient of reactivity was positive, not negative as had been predicted."

I will discuss below the significance of "positive power coefficient."

Mosey worked for several decades in the Canadian nuclear industry, performing various nuclear safety functions at the former Ontario Hydro (currently Ontario Power Generation Inc.). He authored the recent NEI book Reactor Accidents: Institutional Failure in the Nuclear Industry.

Mosey declined to cite technical literature or conference proceedings, or other rigorous sources for his "positive power coefficient" revelation.

Yet Nuclear Engineering International enjoys fluent access to AECL, one of their principal corporate advertisers.

In fact, AECL purchased the entire back page of NEI’s September 2008 magazine to advertise that its signature Candu reactor "consistently outpaces the competition."

NEI could therefore have closely questioned AECL representatives on Mosey’s revelation.

NEI publication of Mosey’s damaging assertion can evidently be interpreted as unrefuted world nuclear industry castigation and warning of engineering carelessness.

Post-Chernobyl nuclear industry representatives acknowledged reluctantly that nuclear reactors with a "positive" power coefficient are vastly more vulnerable to explosive runaways than reactors with "negative" coefficients.

In footnote 1 below, I discuss this danger, as interpreted in 1988 by the Uranium Institute, which attributed the Chernobyl catastrophe partly to this flaw.

Mosey traced AECL’s troubled isotope history: "Since its very earliest days, AECL has produced and … marketed commercial and medical isotopes … The principal sources for medical isotopes were the NRX and NRU reactors. These heavy water moderated reactors were built for plutonium production and nuclear research, and were started up in 1947 and 1957 respectively. In the late 1980s it became clear that continued isotope production would require the construction of a new reactor to replace capacity lost by the closing of the NRX reactor in 1992, and the (then) planned closing of NRU in 2005."

Mosey continued: "Discussions with MDS Nordion resulted in the decision to build a new facility dedicated to the production of medical isotopes at Chalk River Laboratories. According to MDS Nordion, an agreement was made with AECL in 1996 for the construction of two reactors and an associated processing facility to provide a 40-year supply of medical isotopes and to be completed by 2000. In the interim, isotope supplies were to be maintained by NRU."

Finally: "Construction began at the end of 1997 and the two reactors were complete by 2000, with Maple 1 achieving criticality in February of that year. By 2003 it was apparent that delays in the Maple commissioning program dictated continuing to operate NRU past the planned shutdown date of 2005 …"

AECL’s 1996-1997 Annual Report recounted: "In August 1996, AECL and MDS Nordion signed new agreements to secure the ongoing supply of isotopes, and to build and operate two Maple reactors and a processing facility to produce the isotopes. The agreements signaled the end of a legal dispute between MDS Nordion and AECL and have reshaped the business relationship … MDS Nordion will own the facilities and AECL will remain responsible for their safe operation."

"Following public consultation on the Project," touted AECL, "the Atomic Energy Control Board completed an environmental screening and concluded that the Project is not likely to cause significant environmental effects."

If the Control Board had discovered the Maples’ "positive" coefficient, then in light of Chernobyl they would have refused the first license application for Maple, and would surely have begun an investigation of ongoing engineering instabilities at other AECL nuclear reactors.

The Board was succeeded by the Canadian Nuclear Safety Commission, headed early by Linda Keen.

The CNSC might now begin considering more actively each AECL reactor's vulnerability.

AECL’s startling miscalculation of the Maples’ power coefficient hindered government & industry in Canada from implementing solutions to the isotope crisis.

Stephen Harper’s minority Conservative Party Government responded with production–first, safety-second command & control tactics to AECL’s miscalculations. The Harper Cabinet co-opted the Bloc, Liberals and NDP to push Bill C-38 through the nocturnal Parliament of 12 December 2007. Bill C-38 cancelled CNSC control & regulation of NRU for some 120 days.

On January 15, Natural Resources Minister Gary Lunn demoted Linda Keen, who had revealed and resisted risks discovered in November 2007 and earlier by CNSC safety inspectors at Chalk River. Keen indignantly launched a federal judicial review of all aspects of her demotion, whose legal outcome is yet awaited.

I outlined in rabble.ca on April 11 recent geoscientific reports of earthquake vulnerabilities at Chalk River.

Andrew Lewis, Green Party of Canada Critic for the Natural Resources Ministry charged: "the opposition parties rolled over and accepted Bill C-38 without question, and the result undermined the Canadian Nuclear Safety Commission. These parties were unable to appreciate the inherent risks in C-38 and to detect the deplorable anti-scientific bias of Stephen Harper."

PARTICLE ACCELERATORS PRODUCE ISOTOPES

Mosey recommended employing particle accelerators instead of nuclear reactors for production of diagnostic isotopes. A particle accelerator is a machine for producing high-energy, high-speed beams of charged particles for physics applications (more information is available from the Stanford Linear Accelerator Center website at http://www2.slac.stanford.edu).

Nuclear concern NGO Energy Probe has recommended consistently the non-nuclear-power accelerator solution for alleged shortages of medical diagnostic isotopes.

During the September Canadian election campaign, the media and political parties will hopefully review their previous toleration & acceptance of the minority Conservative Government’s patronage of AECL, and Cabinet’s martyrdom of Linda Keen.

FOOTNOTE 1: CHERNOBYL ACCIDENT

Senior nuclear industry experts explicated the Chernobyl explosion not long afterwards, in terms Mosey applied to Chalk River:

"At low power levels the RBMK’s power coefficient is positive. The power coefficient of a reactor governs what happens when more power is added to the core. If the power coefficient is negative, a power rise will be self-limiting. If the coefficient is positive then an increase in power gives a positive feedback effect – the power increase feeds upon itself and power continues to rise unless some other mechanism, such as inserting neutron absorbers into the core, stops it."

The Safety of Nuclear Power Plants: An assessment of an international group of senior nuclear safety experts (London, UK: The Uranium Institute, 1988) p.51.

The Uranium Institute’s lead "At low power levels" referred to the status of Chernobyl 4, whose restart from an uneventful shutdown state was mistakenly perceived by USSR electricity officials in April 1986 as an opportunity to implement a strategic but long-delayed RBMK turbogenerator "test." --Piers Paul Read, Ablaze: The Story of Chernobyl (London, UK: Secker & Warburg, 1993), Toronto Public Library call number 363.1799 REA, p.76.

Ablaze then volunteered a popular description of the RBMK reactor as "unstable when run at low power: in the same way as a jet aircraft might stall at low throttle and then crash, power could collapse in the reactor." (p.55)

The Uranium Institute’s expert Chernobyl panel was chaired by Pierre Tanguy of Electricite de France, the world’s largest nuclear operator. The Institute became the World Nuclear Association in 1995.

FOOTNOTE 2: LINDA KEEN

Harper Cabinet stalwart Gary Lunn demoted Linda Keen, President & CEO of the Canadian Nuclear Safety Commission, a surprisingly staunch advocate of strict, science-based nuclear safety inspection, investigation and regulation under the Nuclear Safety and Control Act.

Lunn simultaneously manages AECL, the leading nuclear operator regulated by CNSC.

Mosey commented days later in Nuclear Engineering International: "Keen responded with a spirited, and significantly more intelligently argued justification for her commission’s position. But, with the inevitability of a clown stepping into a bucket of whitewash, the government removed Keen from her position on January 15." --The ACTivist, 15 August 2008.

Mosey attacked AECL’s glaring business weaknesses in February. He argued that if the radioisotopes produced by AECL and its mediconuclear partner MDS Nordion were so important, "then it is somewhat puzzling that at no time has anyone – AECL, MDS Nordion, or the relevant government ministry taken steps to ensure continuity of supply, or even to raise the issue." --The ACTivist, 7 June 2008.

In August 2008, Mosey likened the Maple reactor "positive power coefficient" to the best-known vulnerability of the Chernobyl RBMK reactor.

The nuclear policies of the Harper minority Conservative Government, which forced passage of Bill C-38 and then promptly demoted Linda Keen for challenging AECL, curiously resemble party-state command & control tactics with no effective opposition in the former USSR.

Stephen Salaff is a Toronto-based freelance environent & public health writer and independent scholar. Salaff is currently contributing expose series to The ACTivist on command & control shortcomings in both the nuclear industry and in Toronto Public Library shutdowns.