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.