Bruce Power played a key role in restoring Ontario’s electrical grid
Do you remember what you were doing on Aug. 14, 2003, at 4:11 p.m., when the lights went out?
It was an unbearably hot day and southern Ontario was shrouded in smog. Suddenly, and seemingly out of nowhere, streetlights went blank and air conditioners fell silent, plummeting 50 million North Americans into the largest electrical blackout ever.
On Kincardine’s picturesque Station Beach, just 20 km south of the Bruce Power site, sunbathers tried to beat the heat in Lake Huron. On days like these, when the skies are a clear, light blue, the Bruce B facility can easily be seen from the sandy shore.
Anyone who looked north at 4:11 p.m. would have seen non-radioactive steam shoot from the roof of the facility (at the time, no units were operating at Bruce A), and, if you were close enough, the noise being generated by the opening of the station’s four Boiler Steam Relief Valves (BSRVs) would’ve sounded like the passing of the world’s longest freight train. A CANDU nuclear power plant’s steam is what turns the turbine and generates vast amounts of carbon-free power. Each unit is designed to automatically relieve itself of its steam if the power it generates has nowhere to go.
This is called a ‘loss of electrical grid,’ and that’s exactly what happened when the 2003 Blackout hit.
Though the release of non-radioactive steam creates absolutely no safety issue to the public, plant or environment, witnessing the BSRVs in action is an experience that won’t soon be forgotten.
Jumping to action
While casual observers surrounding the Bruce Power facility may have been awed – and perhaps even a bit confused – about what was happening, the Nuclear Operators in the Bruce B Control Room quickly referred to their extensive training.
Scott Milley, who was the Shift Manager on Aug. 14, 2003, said there was no warning that Ontario’s electrical grid was about to fail, so once the power from all four units was rejected and the BSRVs opened to the skies, it was all about reverting to their training and following the proper procedures in order to maintain the stability of the units.
“We had good procedures, the equipment worked properly, and we had the right training,” Milley said, adding Bruce B’s units are four of only eight CANDUs in the world that can safely maintain 60% reactor power, provide its own buildings with electricity, and not sending anything outside to the grid.
“The equipment all worked. Everything has to operate properly for the units to stabilize at 60% reactor power – all four units did.”
Bruce Power Operations crews are required to complete six weeks of certification continuing training every year. The 96 hours of training time is split between the simulator (72 hours) and classroom (24).
Bill Fawcett, the Control Room Operator on duty on Aug. 14, 2003, said the exact loss-of-grid scenario had been practiced extensively in 1999, when the impact of the turn of the calendar to the Year 2000 was unknown. The Bruce site pioneered the ‘Response to Loss of Grid Procedures’ in ’99 and all Operations staff were trained on these during that fall’s simulator training sessions, as part of the company’s ‘Y2K’ preparations.
“We had actually practiced these events and these procedures here in the simulator, so we were quite familiar with the procedure… and practice makes perfect,” Fawcett said.
When Y2K proved to be much ado about nothing, the need to be prepared for a loss of grid event was not pushed aside. In fact, Bruce Power, which was formed in 2001 and leased the site from the previous operator, Ontario Power Generation, revised and expanded these procedures and continued training the scenario in the simulator. The training for loss of grid required major simulator grid modelling revisions to support the newly analyzed grid and unit responses. This significant financial investment in innovative upgrades gave Bruce Power the most advanced training model available at the time.
Then, in the spring of 2003, Operations crews were trained on a half-day loss of grid and restoration scenario. In other words, Bruce B’s Control Room was ready a few months later when the exact scenario happened in real-time.
Rebuilding the grid
Once the four units were stabilized at 60% reactor power, Milley received a phone call from Ontario’s electrical grid operators. Though the operators were in a state of disbelief themselves, they knew they had to start rebuilding the provincial system, albeit slowly.
“The grid operator was very relieved – I could hear it in his voice – when I told him I had 1,500 megawatts (MW) of stable power that I could give him, as slowly as 1 MW a minute.”
Normally, Bruce Power would provide the grid with 20 to 40 MW a minute, but with the situation so precarious across the entire province, they wanted power provided as slowly as possible.
“They were rebuilding Ontario, town by town, so they needed the power slowly,” Milley said.
Bruce Power was the first electrical operator in Ontario to provide stable electricity to the provincial grid, a fact that was celebrated by Premier Ernie Eves a few days later on a visit to the Bruce site.