It is the first refurbishment of a Candu-6 reactor but the procedure to polish the ends of the tubes was developed during the refurbishment of a Candu-6 reactor in Wolsong, South Korea. That project started about a year after the New Brunswick refurbishment but is now further ahead.
It was the Koreans who figured this out! With my new nuclear design company for Ontario, I'm throwing out all those old Canadians, and bringing in Koreans! :) *
* for the unionized humour-impaired types, please note that nobody pays any attention to me, and you shouldn't either.