CBC News has also learned that an extensive, months-long investigation into procurement at the nuclear agency by auditing firm Deloitte has been kept quiet for nearly five years.
AECL has refused to comment on the investigation, which insiders say began in 2008 when Deloitte was asked to probe the company's procurement department.
It is unclear what prompted the scrutiny, but former employees say auditors looked into how contracts were awarded to some suppliers of nuclear parts.
"AECL does not want to be accountable to anyone. I have never seen such a secretive and elusive organization, either in a private or public role," said a former employee who wants the Deloitte report to be made public.
"The report would show what I experienced when I worked there — that there is a complete irresponsibility at the senior level at AECL for public monies."
CBC News spoke to several former employees at the company, which developed all the commercial nuclear reactors in Canada before its Candu division was privatized two years ago. All the former staff asked to remain anonymous for fear of repercussions.
They said they saw certain suppliers get unusual preferential treatment — even when their bids were higher than equally qualified companies. The ex-employees said there was also a failure to protect sensitive bidding information from competitors, and bids were sometimes altered after the formal tendering process had closed.
"I saw on several occasions that after bids had closed, it was not unusual to get an unsolicited bid from the chosen supplier with a lower price that would get the job," another former AECL employee said.
The former staffers also allege some senior employees in the company's procurement department accepted gifts and inducements from suppliers of nuclear parts, such as golf games, a shared limo ride to a nuclear industry event and materials to renovate a cottage.
"People would get raw material for personal projects that came from suppliers. I'd seen that. I'd become aware of that. I was told that, in fact, by one of the recipients who chose to share it. Saw photographs of it," the former employee said.
"I'd see abuse of the rules, channelling work into companies that don't deserve it, in my view. And it's just wrong," the person said. "I am convinced beyond a shadow of a doubt that there was wrongdoing there.… A secret is hard to keep. Keeping this out of the public eye, it's incredible.""