All connections between the main generator and the national electricity grid have been broken after a light aircraft crashed into a transmission tower near Peterborough.
Operators anxiously watch six large screens monitoring all parts of the station to make sure the automatic controls begin a shutdown of the generator, closing off the steam supply, the turbine that's driving the generator, and the reactor.
If the shutdown is not completed within 30 seconds and the immense power is not reined in, the turbine will speed up and mechanical parts will fly off like missiles.
Fortunately, this threatened nuclear accident is just an exercise, and the control room is a simulator at the University of Ontario Institute of Technology in Oshawa the only simulator in Canada outside the industry itself.
"The computer running that panel is just like in the plants, but this one is talking to another computer, which fools it into thinking it's really talking to the reactor," explains Daniel Meneley, acting dean of UOIT's Faculty of Energy Systems and Nuclear Science.
Training sessions on the simulator are just a small part of the school's four-year degree course for nuclear engineers.
The 182 students enrolled in North America's biggest university program for nuclear engineers can be assured of one thing when they graduate: a job.
Demand is high for engineers in China and India, where nuclear power generation is on a fast track. And here at home, a large percentage of the 21,000 people employed at Canada's 18 nuclear power stations 16 of them in Ontario are reaching retirement age.
"Retirees are coming out now who went into the CANDU program when I did, and that leaves the company rather sparse for technical skills," says Meneley, who helped build the Darlington reactor for Ontario Hydro in 1974.
"We have been told by Ontario Power Generation and Atomic Energy Canada that there is this demand coming around the corner, and we should be ready to replace all the retirees. We're very happy about the situation."
So is Lisa Grande, who is in her final year of the UOIT nuclear engineering course and has a job nailed down with OPG. Salaries start at $50,000 to $60,000 for nuclear engineers in Ontario, with many OPG employees reporting incomes well into the six figures last year.
"You don't usually come out of high school and say, Yes, I want to work in a nuclear power plant," admits Grande, 29. "But this has worked out so well for me."
When she first left high school, Grande worked on a water bottling production line. "The sheer monotony of it, just doing the same thing day after day, that's what scared me into going back to school," she says.
Grande was drawn to nuclear engineering during a job placement at the Pickering plant.
"Once in a nuclear power plant, I knew I could never get bored in a place like that," she says. "Nuclear is like a blend of technology, it's multidisciplinary and, of course, electricity generation is vital to our standard of living."