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Good morning, members of the committee.
To our invited guests, good morning, and thank you for being here.
Pursuant to Standing Order 108(2), we are involved in the study of the status of the NRU reactor and the supply of medical isotopes.
Members of the committee have been spared the presence of the chair. He is on the road, and I will be filling in for him. I didn't mean that we'd been spared the presence. We will all miss him tremendously, and I'll certainly let him know that when he returns.
We'd like to welcome, as an individual, Mr. Peter Goodhand. Welcome, Mr. Goodhand. Thank you for being here.
And we have, from Covidien, Stephen Littlejohn, vice-president, communications, pharmaceuticals division. Welcome.
As well, we have Philippe Hébert, director of sales and marketing, pharmaceuticals division, Tyco Healthcare Canada.
I recognize some who have made deputations before committee, but I will give an explanation. We allow eight to ten minutes. We invite you to make your presentations during that time. Then we begin with a seven-minute round of questions and answers from the members. We'll try to expedite that. The second round, if that's possible, is usually five minutes.
Without any further ado, Mr. Goodhand, would you like to lead off?
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Hello, my name is Philippe Hébert and I am the director of sales and marketing, in the pharmaceuticals division of Covidien Canada. I would like to thank the committee for its invitation.
Covidien is a health products company with a worldwide presence. The company supplies technetium-99m generators all over the world. In Canada we employ about 500 people in all fields of healthcare and medical products.
In Europe we have a molybdenum extraction facility in the town of Petten, which extracts molybdenum from reactors in Europe. We also have an operations centre there to produce technetium-99m generators. The other centre that supplies Canada and North America is the fabrication centre in Maryland Heights, in the St. Louis, Missouri, area. All clients in Canada are served from that centre.
Covidien traces its roots in this field to the Mallinckrodt company, established over 160 years ago, with headquarters in the St. Louis area. We have continued this heritage. In Canada for the past three years, we have made considerable investments in order to play a more active role in supplying and distributing medical isotopes in the Canadian market.
As you probably already know, there are only two manufacturers of technetium-99m generators in North America. We are one of them. For the past three years our purpose has been to offer Canadian centres a more diversified supply that reduces the risks of supply chain breakdowns that have unfortunately been affecting the medical field. We have had considerable success in becoming an alternate source of supply in the Canada's western and Atlantic provinces. That is why, if you look at the centres in these regions, you will see that the impact of the Chalk River reactor repair process is very limited. That is because of our ability to prove technetium-99m and molybdenum from alternative sources.
I would like to explain briefly how we have been operating since the repairs to the Chalk River reactor began. As a global organization, Covidien has concentrated on supplying its customers. We have contracts with our customers. These contracts are usually for the long term, of at least one year. Our goal is always to ensure that our clients have the best possible supply. Since the repairs to the Chalk River reactor began, we have also established a process to inform the market when additional production is available. We have made a special effort to supply Canada with additional production of technetium-99m generators that can be offered to centres that are not our usual customers here. Such additional production can vary from week to week, but some weeks we have been able to offer 600 curies. To give you an idea of scale, 600 curies is probably one third of the Canadian market's needs. Some weeks, much less is available; other weeks, it is just enough to satisfy our Canadian customers' needs.
Since the beginning, we have made a very determined effort to inform the market of this availability. We have published a calendar that informs the Canadian centres about what supplies we expect to have available two or three months in advance. I will stop here and turn it over to my colleague, Mr. Stephen Littlejohn.
My name is Steve Littlejohn. I'm with Covidien, a global health-care products company. I'm a vice-president at Covidien's pharmaceuticals segment, which is based in St. Louis, Missouri. I also co-chair our global task force that is helping to manage the challenging medical isotope crisis worldwide.
More than 35 million nuclear medicine procedures are performed worldwide each year. Approximately two million of these are performed in Canada using single photon emission computed tomography technology. While many people are unfamiliar with medical isotopes, they or a family member have probably benefited from this technology.
The technetium-99m that comes from molybdenum-99 is a vital medical isotope. It is used in over 80% of all nuclear medicine SPECT diagnostic and functional studies of organs and anatomical systems. The information from these studies is used by many medical specialists, including, among others, radiologists, nephrologists, oncologists, and cardiologists, to better diagnose and treat patients.
Throughout the molybdenum-99 shortage that began with the unexpected and now lengthy shutdown of the NRU reactor in Chalk River, Ontario, now combined with the planned shutdown of the High Flux Reactor in the Netherlands, we have had two primary goals.
Our top priority is maximizing patient access, as fairly as possible on a global level, to critical diagnostic procedures that depend on technetium-99m.
Second, transparent and frequent communications are crucial in our collaboration with the nuclear medicine community to help them plan as efficiently as possible to provide maximum access for those patients most critically in need of this vital isotope. We have also established a special web page to provide easier access to current information on the situation, which can be reached at www.covidien.com/mo99supply.
We believe that we have been successful in meeting both objectives, but a continued strong effort is still necessary over the next few months.
Covidien firmly believes in the value of a diverse supply of molybdenum-99. Long-standing supply arrangements with each of the major medical isotope reactors continue to be highly beneficial, as they have been throughout the shortage. The global molybdenum-99 supply chain is heavily interdependent and can be very fragile. There are many steps between the reactor and the patient. Any one of them may prove hazardous if all does not go as planned.
I'll depart from my remarks briefly right now to explicate that. Let's say that we start with a reactor. We'll talk about the Maria reactor in Poland. They'll do the irradiation cycle. That might take six or seven days. This reactor is about 30 kilometres east of Warsaw. When the irradiation is complete, the targets are put in special containers--a target is about the size of a ruler--and for about 22 hours they're trucked across Poland and Germany to our facility in Petten in the Netherlands. The processing period may take about 16 hours. Then the product is moved to a technetium generator facility in Petten or Europe or Africa. Also, molybdenum is shipped by air to our facility in Maryland Heights. It takes about 12 hours to get it across and into St. Louis. There's a six- or seven-hour production cycle, and then it's in the air again to patients.
If you calculate all of that, from the point at which it leaves Warsaw, Poland, to the time it reaches a patient in Canada, it is a matter of hours. You can add it up, but it's a very short time. It's very complex. Everything has to work right at each stage along the way. And as you know, and as you've heard many times, it can't be stored. It's all real time, and it's all a batch process.
Obviously, having two primary reactors down simultaneously is an extreme example of a break in the supply chain. In preparation for this possibility, Covidien took additional precautionary actions.
Since last May, Covidien has taken a host of measures to lead the industry in addressing the supply issues affecting the availability of medical isotopes. Some were designed for immediate impact. As I just mentioned, Covidien and the Institute of Atomic Energy in Poland, or IAE POLATOM, announced an agreement last month that will provide an additional resource for this critical medical isotope. The agreement adds IAE POLATOM's Maria research reactor to the global supply chain for molybdenum-99. More than a million additional patients are expected to benefit from this additional supply in just the first six months.
If you do the math, if you have roughly 30 million procedures in the world that use technetium and you multiply the one million to two million for annual.... At two million, you're getting close to 10%. That is not a lot in the grand context, but when you look at the millions of patients being helped that otherwise wouldn't be helped, and having a supply when there wouldn't otherwise be a supply, it makes a difference. I do want to note too that it brings the first new reactor into the worldwide supply chain in more than a decade to help meet the demands of medical isotopes in this time of critical shortage.
What I'm about to say is really important, and I want to really emphasize it. We work closely with Health Canada and the U.S. Food and Drug Administration, or FDA. Those two agencies worked together and collaborated in an extraordinary, admirable kind of way to ensure that approval came. But I want to make very clear that this was not a shortcut approval; this is what I call expeditious rigour--with the emphasis on the rigour.
We had people on both sides of the border in the regulatory agencies willing to work on weekends, willing to take pieces of material and process them. It was an extraordinary effort by the regulatory community all the way around to do two very important things: get molybdenum into the supply chain and into technetium generators for patients, but at the same time ensure safety. You've got to have both at the same time when you're working in this. So that was really extraordinary, and we're very grateful for that.
However, as I mentioned before, adding Maria will not completely replace the molybdenum 99 supply lost to the NRU or HFR shutdowns. As I said, it can only address about 10% of world demand. So our efforts towards maximizing the molybdenum supply arrangements with all viable sources continue.
We actively supported additional production cycles and an increase in the number of targets at Belgium’s BR2 reactor during the shutdown of HFR, and we continue to increase the production of the potential alternative: clinically appropriate medical isotopes such as thallium TI 201.
The combined use of molybdenum 99 from the remaining online reactors--Maria, BR2, OSIRIS in France, and Safari in South Africa--improves the outlook for the coming months. But we estimate intermittent ability to fully meet existing customer orders, with some periods of more serious shortages for technetium generators. This variability will be due to already scheduled brief maintenance shutdowns of the remaining molybdenum supply, including Maria.
Just to give you a better sense of that, referring to our calendars that we issue periodically.... We have one that will be issued as soon as we can get it translated into French into the Canadian market, rightfully. But just to highlight that, May is going to be a particularly difficult month. It could be difficult across the world. But at the same time, there are a number of dates in May that will be better, or at least not as bad, primarily because of the Maria reactor. The bright spots are May 9, 10, 20, 21, 28, and 29.
So we would hope with our communications that we can help physicians and other clinicians schedule appropriately to avoid the bad shortages and maybe be able to do it when there's a little bit extra available.
But we're not looking at just the short term, we're also looking at the long term. In January of 2009 Covidien formed a partnership with Babcock & Wilcox Technical Services Group, or B&W. We're collaborating to develop solution-based reactor technology for medical isotope production. This will combine our expertise in radiopharmaceutical production and processing, and global regulatory approvals, with B&W’s patented liquid phase nuclear technology, and will utilize low-enriched uranium or LEU. The current target for completion of that would be the middle to latter part of 2014.
We've also expressed support for the Dutch government’s efforts to develop the new Pallas reactor in the Netherlands. In addition, the Missouri University Research Reactor, or MURR, is also prominent in efforts to become a U.S.-based source of molybdenum 99 using LEU. Covidien is evaluating MURR as an optional supplier.
We also support the American Medical Isotopes Production Act in the U.S. Congress. The act promotes U.S. production of molybdenum 99 for medical isotopes manufacturing while also phasing out the export of highly enriched uranium for medical isotope production.
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There are two diversities about which we're speaking. I think you have the diversity of the PET, cyclotrons, accelerators, and other methods of getting moly-99. As I said earlier, many of them have shown they can make it. The question is whether it's economical and commercial-scale, in terms of size. That is not to say avoid going there. I think, for the sake of patients, you have to look at all avenues there.
The other diversity we're speaking of is recognizing that technetium-99m will be with us for a while, and I have to defer to the doctor as to how the clinical community views its balance of supply, cost, and efficacy. I'll defer to them on that. In that respect, it's a matter of securing diverse supply from reactors, then understanding that the reactors use a processing facility. There's a distinction. On your first set of reactors, they irradiate the targets, and then you have a processing facility that dissolves the targets and extracts the 6% of moly-99 that's in the targets. There are a few processing facilities. We have one. IRE, in Belgium, has one. MDS Nordion has one. NTP, in South Africa.... And then when the time comes and ANSTO, Australia, comes on line, there'll be one there. So that's a critical component there.
So it's having that diversity apply. It's also really important to understand that in the reactors, when they irradiate, it's a batch process. When NRU and HFR were down they had more batch processes end to end, and this operated for 200 to 250 days a year.
What we're facing right now is the other reactors don't operate as often, so what you're trying to do is match the reactor schedules such that you can have some across the board, and then at certain points you have a little more. This is why, if you look from week to week, it's a saw-tooth kind of pattern. It depends which reactors are operating.
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I would echo those comments. There are definitely two levels of diversity.
We also talked about--and I think you mentioned it--the issues of interchangeability. On part of the problem today, you heard that the target that gets irradiated looks like a ruler, but in a different place it looks like a pencil. You can't make the ruler go through the slot, so it's a matter of the interchangeability of those targets. If they all looked the same or there was flexibility, targets irradiated in different reactors could be processed in different processing facilities. If they're unique to that piece of technology within the reactor model, they're not interchangeable.
Then there's a second level of diversity, which means looking at things like cyclotrons.
There is the opportunity to have redundancy within a facility. If they feel there's a critical point, rather than having just one processing line you could have two processing lines so that one could be maintained and the other operated.
So there is redundancy in that straight chain and interchangeability between the chains. That will be particularly important in North America. Because of the shipping times, it's better to have a regional solution where there is a great deal of interchangeability, and perhaps secondarily, the ability to switch from Europe to Africa, North America, and Asia, but certainly within a regional geography.
As we think about long-term solutions it will be incredibly important that U.S. and Canada collaborate, not just in supply agreements, but in technology design and complementarity.
I would like to introduce Mr. Bill Pilkington, the chief nuclear officer at AECL.
[English]
My colleague Bill Pilkington and I appreciate the opportunity to be here.
[Translation]
We will also be very pleased to welcome you to our Chalk River facility on April 13.
[English]
We very much look forward to hosting you.
I would like to provide members of the committee with a brief update on our most urgent priority at AECL: the safe repair and return to service of the NRU. Bill will then provide more technical detail on the next phase of the repair sequences.
As you know, intense repair operations continue around the clock, involving over 300 highly qualified AECL staff and industry partners.
[Translation]
There are 300 of us working around the clock on the repairs.
[English]
As of today, the weld repair portion of the outage is 60% complete.
The process has been very painstaking. Our progress has been impeded by the need to overcome technical problems, to inspect, analyze, and understand irradiated metal behavior, and to measure and evaluate stress on the vessel structure. What we are doing has never been done in the history of the nuclear industry. It is probably the most complex, precise, and sophisticated welding operation ever undertaken in a radioactive environment.
The challenges have been daunting, but weld by weld we are getting to our goal of safely repairing the NRU and restarting it. We have successfully completed eight of ten weld repair sites, representing more than half of the repair work. When you do visit Chalk River you will see the nature of the challenges and the solutions our people have devised to meet them.
We have invented and are using many innovative remote tools. These complex tools, equipped with vision systems, have to be compact enough to pass through a very small opening at the top of the reactor, about the size of a baseball that could fit through. They are then fed nine metres down into the large reactor vessel, where they unfold and align with the vessel wall. Welding is controlled by operators with TV screens and joysticks, three storeys above the repaired site.
Through excellent teamwork between our employees and suppliers, and with the best advice from the world's most eminent welding and technical authorities, we are getting the job done.
The two remaining areas of corrosion, the ones presenting the biggest challenges, are now being tackled. The relatively large size of the two remaining repair sites makes them by far the most difficult and complex. For each of these repairs, four distinct phases of work must be completed in sequence, all adding time to the job but absolutely necessary.
In light of this complexity and the accumulated experience from the repair work completed to date, it became evident to us that the schedule needed to be revisited.
AECL, with the advice of industry experts in welding technology and performing outages, has conducted a review of the work schedule. The result is that we now estimate NRU will resume isotope production by the end of July. This new schedule has built in prudent contingency, reflecting the difficulty inherent in these final repairs.
Repairs are expected to be complete for the first of the remaining sites later today. For the final repair site, the first of four incremental phases—weld development—is under way. Regular progress updates will continue to be provided based on the revised schedule.
Mr. Chairman, all of us at AECL feel the pressure every day to get the repairs completed as soon as possible so that medical isotopes from NRU can be used to help patients all over the world. Having said that, we absolutely must get these highly delicate repairs done right. There is no margin for error. We have but one chance to develop and execute the correct repair strategy for each unique repair site in the reactor; otherwise we risk damaging the vessel wall and extending the repair.
Bill will discuss the repair operation in more detail in a moment. He will also outline in more detail the reasons for the revision of our estimated return to service. The extension to the repair schedule is indeed regrettable. We are deeply aware of its implications on isotope supplies for patients.
So let me reiterate. AECL is making every effort to return the NRU to service as quickly and as safely as possible. More resources are being applied to the project, including additional aluminum welding specialists and other technical expertise.
Mr. Chairman, I would now like to turn things over to Bill Pilkington to continue our opening remarks.
:
Thank you, Mr. Chairman.
As Hugh MacDiarmid just stated, the NRU repair and return to service is making steady progress in addressing the remaining unique repairs. Now we would like to take this opportunity to provide additional detail on the repairs and highlight how our outage team is successfully managing the repair process.
The final sequence of repairs is the most challenging. The repair areas are the largest, increasing the complexity of achieving a lasting repair while managing the stresses on the vessel. Each of these repair sites requires a unique strategy in repair design. The repair team is now employing a combination of welded plates, vertical and horizontal structural welds for plate attachment, and finally, both vertical and horizontal weld buildup.
We now have completed the repair design for the remaining sites. With this information and the experience gained in the last sequence of repairs, we have revised our outage schedule, which has resulted in the extension announced recently.
To confirm our revised plan we assembled an expert advisory panel earlier this month for a workshop to examine our repair strategy. The group includes Canadian and international experts in specialized welding solutions, reactor technology, and outage management. The panel confirmed that AECL is using the correct repair techniques, that the NRU is indeed repairable, and that our revised schedule is realistic. The panel also agrees that AECL is appropriately balancing the competing priorities of a lasting repair, minimizing the risk of damage to the reactor vessel, and minimizing the outage duration.
The process of preparing to complete the final and largest repair involves four phases, which must be carried out in sequence. These phases are weld development, welder qualification and reliability testing, integration testing, and finally, the repair of the vessel.
Weld development is the longest and most difficult phase to plan and schedule, since a number of weld trials and engineering analyses must be completed to arrive at the optimum solution. For the final repair site this process began in January, and steady progress has been made to date.
Next, the weld machines must be programmed, specific weld procedures must be developed, and the welders qualified to complete them. The repair sequence must be refined to allow the welders to train on the techniques to the point that a quality weld can be made repeatedly. This process is referred to as qualification and reliability testing.
After successful completion of the welder qualification and reliability testing, we proceed to integration testing. This is a full rehearsal of the repair from start to finish. All of the remote tooling to prepare the vessel for welding and to complete the repairs is used in the full height mock-up to confirm that the teams, and the execution of each of the procedures, fit together to deliver the required result. The reason we spend so much time on the rehearsal phase is because once we're in the vessel we need to get it right the first time.
Finally, when all of these phases have been completed flawlessly, the repair team is ready to go to the reactor vessel. The preparation is extensive and time-consuming, but the results speak for themselves. To date every repair site has passed all required non-destructive examination. To minimize the time required on the outage-critical path, we continue to work on a 24-hour-day, seven-day-a-week basis without interruption. Returning the NRU to safe and reliable operation to support medical isotope production remains the focus of the outage team and AECL's primary objective.
Thank you, Mr. Chair.
With your permission, I would like to show some samples of the repair welding. I think they would help to understand the complexity of this job.
This weld was actually made in a mock-up. It was made through a 12-centimetre opening some 30 feet away from the actual plate. This sample is made of ethyl material that is the thickness and the curvature of the vessel. This was actually done on November 15, mid-November. This was a test weld.
We went to the vessel and did the first repair on December 12. Through December, we completed a total of five repair sites and they went very well.
We believed the process would continue with the learning and that we would be able to get more efficient at doing these repairs as we progressed through the more difficult sites. That actually was not what occurred.
I don't know if you can see the back of the plate, but we've actually machined these samples to replicate the corrosion in the vessel. From all of the inspection we've done, we have a very accurate model of the corrosion in the vessel, so these plates have been machined to exactly replicate that. You can see this area.
This repair required changing technique because of the stress on the vessel, and this what is taking the additional time. In this case, we've actually had to add structural plates. This is not complete, by the way; this was a sample in process. These plates are actually structural and they're welded in with fillet welds around the plate before we move to weld buildup. I point out that these are nuclear-grade material. The welds and weld procedures are using nuclear-grade material and being done to nuclear standards.
Having put the plates in place on that repair site—and by the way, that is the site that is actually being repaired as we speak; we're actually doing this repair today—in the final repair, we have the plates and then we apply weld buildup below, above, and on both sides to complete the repair process. I would point out that you can probably see, even at a distance, that there is a significant amount of deformation in the sample plate. That is why we had to go to this type of a repair in order to reduce the stress on the vessel. It's the development of this that has taken significant time. On this plate, there are a number of defects. This was plate number 9. In fact, we produced 30 of these samples in order to be prepared to go in the vessel and complete the weld that we're doing today.
Finally, regarding the last site, if you look at the corrosion here, it actually stretches from end to end. This is the largest site. The area that is deeply corroded, with less than a millimetre of vessel wall remaining, is quite large in this area. For this repair—and this is not complete—we have completed the design, and it will involve nine thicker structural plates. Then we'll have to develop specific weld procedures—because these plates are spaced differently than the ones in the last sample—to in fact do the structural welds around the plates. Then we will, in similar fashion, build up below, above, and all the way across in order to cover the area of corrosion.
This is the job that lies ahead, and again, all of this meets nuclear standards. The repair is done by authorized authorities that carry certificates to do this type of repair, and all of the materials are nuclear materials. This will be inspected to meet all of the requirements for the vessel and will be accepted by the regulator when it's done. This will give us a lasting repair.
To respond to your comments, to the best of my knowledge the $8-billion figure that you reference is accurate in terms of the accumulated government support in AECL. A very substantial portion of that is for the support of the laboratory, which is by definition a pre-commercial institution. It's not designed to be profitable. It's designed to provide support for pre-commercial research for the nuclear sector. Indeed the amount of funding support provided in Canada could be characterized as modest in comparison to some other nuclear countries, so that price tag does not surprise me.
If we look at the impact of the nuclear sector on the Canadian economy over that period of time, the economic benefits have been many multiples of that investment, through the production of electricity that's been reliable and safe and low cost in Canada, and from reactors we have sold abroad.
The $300 million in funding support being provided for this year is to support a number of activities, some of which are related to the repair of the NRU and the preparation for the relicensing or the licence extension of the NRU. The majority of that amount is earmarked for the unexpected financial requirements associated with the completion of the life-extension projects at Bruce Power and Point Lepreau. I think I've talked before about the other requirements that we have under our contracts: the need to complete those projects safely and with good quality, and to meet our customer expectations in those life-extension projects.
I believe the future of Chalk River Laboratories is a bright one, if we are able to move forward with the plans as they currently are laid out and the laboratory is able to continue with its mission of providing research, development, and innovation support for Canada's nuclear industry. That is vitally important for the future of the CANDU brand worldwide.
With respect to your specific question about the Montreal office, that office will be very heavily occupied for the next while in supporting the life extension of the Gentilly-2 reactor for Hydro-Québec. That project is going to be commencing activity on the work site very quickly.
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They're not, so in adjusted dollars we're talking about a $19 billion investment since the early 1950s. The notion that the government would then put the sale of such an asset into a budget, excluded from any sort of consideration of the net benefit for Canada, should be offensive to anyone who ever contributed a dollar to AECL over the last nearly 60 years.
Mr. Regan asked earlier about the various status updates on this repair. I'll take us through a little memory lane here, and these quotes are all directly from your updates, so I'm not putting anything in here. In May 2009 the anticipation was for more than one month, so that pushes us forward to June 2009. At least three months was the update in status report number six, pushing us to September; then a month later, in July, “it is now clear that the NRU will not return to service before late 2009”. That's another adjustment; we're now looking at maybe November or December. Two months after that, in August, you say “the NRU will return to service during Q1 2010”, so that's another adjustment.
Then status report number 34 in December, several months after that, says we're pushing it right to the very end of that quarter, meaning the end of March; in early January we hear it could extend to April, and two weeks after that, status report number 40 says NRU's target return date is confirmed as April.
Then in February, a month later, we learn it will be the end of April; in March, it will be during the second half of May. On March 17, a week later, you say AECL is currently revising, so just a week went by between the update to the public saying it would be May for sure until you were saying to hold on because you were revising. Then the most recent announcement, on March 25, which was update number 48, says “NRU will resume isotope supply by the end of July”.
It's 700% over budget. I fail to see how this doesn't affect the reputation of the organization in its ability to make accurate predictions about its own viability. Today you've informed us that it's 60% finished, yet the most challenging work is still ahead.
I'm deeply concerned. Neither of you is in the health field, nor are many of us, but we understand the impact on Canadians of not having a reliable isotope supply in order to be able to access reliable and safe diagnosis.
The record I just read is not one to be proud of, I would suggest. It's 700% over budget. There have been constant delays, and announcements of further delays. Canadians are feeling the impact and the concern when, as they saw just last week, operations and procedures are cancelled. I don't know how this does anything but hurt the reputation of this organization.
:
Thank you, Mr. Chairman.
I'll be sharing my time with Mr. Anderson.
Through you, to our witnesses, thank you for coming today and also for the updates that you have been giving to the stakeholders in the surrounding communities. The people in Chalk River, Deep River, Pembroke, and Petawawa feel that the NRU and the work that AECL does is part of their community. They feel some responsibility, not only because of the workers but also because we have family members there who are dependent on cancer diagnosis. That's what I'd like to focus on, as opposed to the cost or the politics of it, but the people. This is why it's such an urgent matter. Even cancer patients who are not impacted by the shortage are still worried about it because of the complexity involved, and it causes extra anxiety for them even though the NRU did develop the cobalt treatments, which patients are receiving in good order.
You mentioned and showed us how the repairs are complex and that there is little margin for error and that a lot of practice welding takes place before you actually weld in the vessel.
Can you tell us what kinds of errors you're guarding against and the consequences of different kinds of errors, and how the proximity to the NRX has been of benefit, if it has? Has this process we are going through, this learning, fixing, delaying process, been helpful to other older reactors going through the same process? Because they do help patients, including Canadian patients.
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Yes, I'll see if I got the entire question. First of all, you asked about the types of errors that we need to guard against. There are really two concerns in doing the repairs. One is, if we do a repair that results in excessive stress on the vessel wall, there is a mechanical seal that sits about six inches below where we're doing the repairs, and if that seal is disturbed, then it would be very challenging to reseat it on a reactor of this age. So a lot of effort has gone into developing stress models for the vessel and running through different repair scenarios to find the ones that give us the least stress on that lower seal on the vessel. So that's one of the challenges.
The second challenge is that if an error is made in the welding in the vessel, and if the wall is damaged, then we need to back out, and that essentially becomes a new repair site. We would then have to design the repair for the damage that was done. We would have to go through the whole process--the stages of development, qualification, integration, testing--so that could easily add months to the process. So it's critical that we get the job done right the one time we're in the vessel. To say we've done eight out of ten so far, and we're doing the ninth today.... It is going well. We believe we have the right amount of preparation.
On the proximity to the NRX, yes, we've actually used the NRX. It's geometrically quite similar to the NRU in terms of the layout, so we were able to build a mock-up there early and start practice. It's in an environment where, with that part of the NRX, there's no radiation field, so the workers can work at the right height, in a similar environment, but without any radiation present. So that's been very helpful.
Finally, in terms of the benefit, we've developed a lot of first-time tooling for this job. One of the biggest challenges was in fact to be able to design, build, and commission all of the tools required to do this repair. While it may not be directly transferable to other reactors, the remote repair techniques that have been developed here are generically applicable to many, many situations. So that will be a benefit when other companies or reactors come to AECL to help with inspections or repair. The tooling development and the vision systems that have been developed for this will be of great benefit.