Ontario Power Generation has announced it will spend $600 million to refurbish its second-largest hydroelectric plant, the R.H. Saunders Generating Station in Cornwall, with the added bonus that better technology will result in a boost in output.
It will be the second refurbishment for the Saunders Generating Station, which was commissioned in 1958 followed by a ceremony presided over by Queen Elizabeth II and U.S. vice-president Richard Nixon.
The 1,045-megawatt station forms part of the Moses-Saunders Power Dam shared with the U.S.
OPG director of plant operations Scott Gagnon explained recently the project will unfold past 2040 with the goal of refurbishing one of the 16 generating units each year.
Gagnon said two potential constraints on the project are ensuring there are enough skilled trades to maintain the project schedule and keeping the plant’s 300-ton powerhouse gantry crane, which supports lifting major components including each of the 62-ton turbine runners that will be overhauled, in service shape.
Any problem with the gantry crane could bring work to a “standstill,” but Gagnon noted it was upgraded itself relatively recently so he doesn’t expect problems.
Monitoring millwrights
The supply of trades, meanwhile, has to be monitored closely.
“For the team, (the biggest challenge) has been the availability of the trades resources, with the amount of growth in the province between new projects and refurbishment on the nuclear side of the industry in the Toronto area,” said Gagnon, noting that post-COVID some hiring halls were “empty.”
“That was a challenge and it’s definitely a focus area. We have to make those long-term investments in schools and really promote folks to get into the trades.”
There has been close collaboration with the millwrights union, Gagnon said.
“Definitely with a refurbishment, it’s quite a variety of skill sets, especially in the trades, millwrights being one of the key skill sets, electricians, control technicians,” he said, also mentioning welders, carpenters, labourers and crane operators.
“As well, it’s just not the trades, we have engineers onsite for the…design of the servo motors, the design of the equipment itself from the manufacturer. It’s definitely an across-the-board skill set.”
The project is expected to employ hundreds of trades, OPG said.
Saunders produces enough electricity to power 800,000 homes annually, meeting up to five per cent of Ontario’s needs in recent years. The infrastructure program will produce up to 160 gigawatt-hours of additional electricity each year, the equivalent to supplying more than 19,000 homes, OPG said.
Gagnon said innovations such as a change in the design profile of the blades will boost productivity.
“The blade design really transmits into more efficiency so we can run the unit at its best efficiency point over a wider operating range, which allows us to make the most efficient use of the water and get more energy out of it,” he said.
Sensors allow maintenance upgrade
Other upgrades include new online monitoring equipment, with modern sensors producing data to help OPG make better maintenance decisions, Gagnon said, and the adoption of new Teflon-based bearing technology.
“The drive train equipment is classical equipment, but it was re-engineered,” Gagnon said.
OPG also replaced the headworks and tailrace cranes used to help block water for any unit while work is being performed, and there has been ongoing refurbishment of the station’s main output transformers.
G9 is the first of the station’s 16 units to be refurbished, with Gagnon reporting the job has reached the halfway point. There is a reconditioned rotor ready to be reinstalled, and then the unit will be realigned.
“Those are key milestones,” said Gagnon. “Then after that, it’s just return-to-service testing and verifying new control systems. So yes, we’re feeling really confident going into the summer for return to service.”
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