A provincial arbitrator's decision released Dec. 23 reinstated eight of the workers who were fired in November after allegations of illegal drug use.
However, the decision wasn't made public until a Dec. 28 memo from OPG President and CEO Tom Mitchell to staff at the giant utility.
"Because of the highly public nature of the dismissals and the challenge this event had on OPG's well earned reputation, I want to let you know appropriate labour relations processes were followed and have now concluded," Mitchell wrote.
The cases of the three who did not get their jobs back did not go to arbitration, and the arbitrator told OPG not to publicly release the names of the individuals involved or the information that was used during the hearing.
"What I can tell you is three individuals will not be returning to OPG," wrote Mitchell.
"The arbitrator has reinstated the remaining eight employees with varying levels of discipline, which in some cases include significant restrictions."
A spokesman said OPG could not speak to the specific discipline measures in the case, but "generally penalties can include suspensions, loss of pay and potentially demotions or other workplace restrictions."
The Progressive Conservatives questioned whether an arbitrator should be able to overrule an employer in such circumstances.
"That's definitely something that should raise a concern, that someone could decide, no pun intended, arbitrarily that these people get their jobs back," said Opposition critic John Yakabuski.
"We don't know any of the details surrounding these firings, but somebody obviously made a determination at some point that whatever happened here was a justifiable reason for terminating employees. So an arbitrator making that ruling raises questions and we don't have the answers because no details have been released."
OPG called in police last month to investigate the allegations of drug use and a misuse of company resources by the workers, who were described as support and cleaning staff.
The utility has said all along that safety at the nuclear facility was never compromised, and no charges were ever laid by police.
The employees were reported to be using company computers to send emails about drug-related activities, but officially they were fired for violating OPG's code of business conduct.
"When it comes to business ethics, each of us is accountable for doing the right thing," said Mitchell.
"The code sets a standards for the way we work and the decisions we make, and it helps define our culture."