My impression of the MAPLE reactor is as being largely a production facility as opposed to a research and development facility that facilitates the training of many scientists and engineers. There would have been many nuclear engineers working on the MAPLE reactors. I'm not really an expert on that point.
Your question is about the loss of expertise at Chalk River. There is a sense that Chalk River Laboratories is not what it was, say, 20 years ago. There were more diverse research programs going on at Chalk River about 20 years ago. Over time, the core mission of the facility has gradually narrowed onto pretty much exclusively CANDU technology; that has come at an unfortunate cost of general research, and that has led to a loss of certain expertise. There was a particle accelerator there at one point that was called TASCC--