Before you hear from the scientists, some background for the non-specialist:
Recognizing the probity of making sure there was a backup to the Chalk River, Ont. nuclear reactor that produces 40 per cent of the world's medical isotopes, Atomic Energy of Canada Ltd decided, back in the 1980s, to build that backup. Then MDS Nordion, the private company that was spun off from AECL, got involved. MDS takes the isotopes from Chalk River, processes them, and then wholesales them to pharmaceutical companies who distribute them to hospitals and clinics around the world. Recognizing the value of securing a supply of isotopes, AECL and MDS agreed that AECL would build not one, but two backup reactors to the NRU reactor at Chalk River. This pair of reactors would be dedicated to isotope production (The NRU is a research reactor and there are often competing claims on the facility between research and production). MDS would foot the bill, incidentally, for the construction of these reactors, not the Canadian taxpayer. MDS was essentially hiring AECL to be its contractor.
Engineers got to work and the MAPLEs were born. Just one MAPLE alone could easily produce the entire global demand for isotopes.
AECL began working with a plan to bring them into service in 2000.
Then things went off the rails. The machines were built — right next door to the NRU, in fact — and they have “gone critical” and have been fired up to 80 per cent of their power. The targets for the production of the medical isotope moly-99 were inserted and irradiated and moly-99 was indeed created inside the MAPLE. No moly-99 was harvested, mind you, because the facility was still in testing mode.
AECL engineers were trying to convince the regulator, the Canadian Nuclear Safety Commission, that it had designed and built a safe pair of reactors. Part of the way nuclear regulators are convinced a reactor is safe is by having the scientists predict what the reactor will do under certain conditions and then firing up the reactor to see if, in fact, those predictions were correct. For one important variable, though, the AECL engineers predicted x and the reactor did y. The variable involved was something known as the power coefficient of reactivity or PCR. Some reactors around the world operate with a positive PCR, some are operated with a negative PCR. The AECL physicists did their math and predicted that the MAPLEs would operate with a negative PCR. Then they turned them on and, whoops, there was a slightly positive PCR.
That much we know. As to the causes and consequences of this mismatch between theory and reality, there is much debate. But at the end of the day, the regulator has the hammer and the regulator, believing this mismatch represented an unsafe condition, refused to let the MAPLEs get licensed. And so, in the spring of 2008, AECL, with the backing of the government, canned the MAPLEs. The project was hundreds of millions of dollars over budget, eight years behind schedule, and, in the opinion of AECL executives, there was no hope that their engineers were going please the regulator and sort out the theory/reality mismatch.
AECL, though, never consulted MDS Nordion about this. MDS Nordion had, by last spring, paid AECL $350 milion to build these things and then AECL just ups and walks away. MDS shortly thereafter sued AECL and the government claiming $1.6 billion in relief.
A year later, that fabulous but rusting NRU reactor springs a leak and is now offline at least through the summer and quite possible longer. A medicial isotope crisis ensues.
MDS Nordion and several nuclear scientists and medical specialists emerge to say it would be irresponsible of the government not to take a second look at the MAPLES. One source told me they could be producing isotopes by the end of the year — safely — if not for the bloody inflexibility of the regulator.
On Thursday this week, four scientists, including one who was the manager of MAPLE commissioning for AECL, testified at the House of Commons Standing Committee on Natural Resources. Some excerpts:
Jean Koclas, Professor, Nuclear Engineering Institute, Engineering Physics Department, École polytechnique Montréal: If you don't know how the nuclear industry works: usually, when you modify something in a nuclear reactor, when you bring forth a new type of reactor, most of the time you have unforeseen difficulties. You can think of the Darlington reactor, which was just an increment in size of a standard design, and engineering problems arose which took more than a year to solve. So I think the MAPLE reactors, MAPLE-1 and MAPLE-2, do not escape these sort of engineer constants.
So as far as we know, the MAPLE reactors have been stopped last year mostly because one technical issue has not been solved, namely the positive reactivity coefficient. This reactivity coefficient was predicted to be negative… Similar calculations done on the MAPLE project were performed by other laboratories in the United States, all of them reaching the conclusion: this positive power coefficient should have been negative.
… although some efforts were done by AECL, Atomic Energy of Canada Limited, to explain this positive power coefficient, the full explanation was not found. Because you find yourself in a situation where if you cannot predict a simple coefficient as the power coefficient, then can you be sure that the nuclear safety analyses that are based also on the calculations are correct?
It is our opinion, however, that the MAPLE reactor project should be reinstated and that sole technical difficulty be tackled by a group of people involving not only AECL, but people from outside this company, maybe some other organizations and also including universities where we have, over the last few years, made very powerful modifications to transport theory, nuclear reactor calculations, as well as fluid flow and heat transfer. So I think we should put together the resources to analyze this situation and predict correctly the positive power coefficient so that this technical issue can be solved and the world problem of Molybdenum 99 and Technetium-99m be solved once and for all. It is my opinion that this country should put some of its resources into solving this problem.
Jatin Nathwani, Ontario Research Chair in Public Policy for Sustainable Energy Management, Executive Director, Waterloo Institute for Sustainable Energy, University of Waterloo: … it makes sense to revisit the decision to cancel the MAPLE reactors. I understand there are technical issues that need to be resolved and there's a regulatory dimension to this as well. A strong recommendation by this committee to revisit the decision on the cancellation of the already built and partly commissioned MAPLE reactors is an option. If accepted by the government, this could pave the path for subsequent resolution of the technical issues.
Such a recommendation coupled with a requirement on the agencies whether it's AECL, Industry, CNSC and others, to develop an action plan with a formal quarterly progress report to this parliamentary committee would provide a sufficient degree of focus, public accountability and a high level of attention. Whatever the business model whether it is a public/private partnership, sole government or some other, the goal is to ensure that the national interest is taken into account.
So we have to frame this problem as an important national problem, bring a sense of urgency to its resolution and enlist the vast expertise within our regulatory bodies, industry and the academy. But this will require in my view an enormous amount of good will coupled with a step-by-step problem solving attitude and vigorous measurement of progress against goals.
… A parallel path followed with urgency can bring the already built MAPLE reactors to an operating state or perhaps the next six to eighteen months. And such a strategy offers the best prospect for putting Canada on a firm footing for assurance of supply.
Daniel Meneley, Acting Dean, Faculty of Energy Systems and Nuclear Science, University of Ontario Institute of Technology: .in spite of the obvious weaknesses associated with the MAPLE facilities, [I believe] that start-up and operation of these facilities may well be the preferred route as has been mentioned by both other speakers. It may well be the preferred route to solving the immediate shortage of radioisotopes. Yes, there will be problems. Yes, this may not be possible until well after completion of the present repair processes at NRU. However, at the end of that sequence of events, that is the repair of NRU, there still will be no backup supply of radioisotopes for a very long time to come. At the very least, MAPLE might help to fill this time gap.
I'm aware…that other countries are gearing up now to replace and to augment the supply of Molybdenum-99 from their own countries. So that the gap filling by MAPLE may well be the best thing we can do for both Canada and for the world. I come to the fundamental question to be answered and I believe the committee is to be commended for investigating this question, if not MAPLE, then why not MAPLE?
Harold J. Smith, former MAPLE commissioning superviser, AECL: I and my team took both MAPLE 1 and MAPLE 2 to criticality. We measured the positive PCR and we participated in the subsequent efforts on positive power coefficient of reactivity. I understand from the newspapers that there has been a team of experts who claim that MAPLE would never be functional. I now ask the rhetorical question – who are these people?If anybody qualifies as an expert on MAPLE, I think I'm it. Nobody has asked me or anybody else involved in the project what we think.
… there are two MAPLE reactors, each with the capacity to deliver more than the current world requirement. Positive PCR requires a relatively simple engineering fix to restrain the bowing of the elements and to reduce the PCR to approximately zero. I thank you for your attention, and I hope this doesn't turn into another Avro Arrow.
