New Ontario Power Gen study supports Darlington nuclear refurbishment

Ontario Power Generation (OPG) on Oct. 5 released a report saying that continued operation of the Darlington Nuclear Generating Station will take the equivalent of two million cars a year off Ontario’s roads by avoiding significant emissions of greenhouse gases (GHG).

The report, prepared by Intrinsik Environmental Sciences, compares the environmental impact of running the Darlington station to 2055 against other energy supply options, such as natural gas-fired generation.

“Our study concludes that given Darlington’s large role in energy production in Ontario and low levels of greenhouse gas emissions, the refurbishment of the station significantly lowers Ontario’s carbon footprint versus other forms of electricity generation,” said Elliot Sigal, President of Intrinsik.

The study concluded: “The total reduction in GHG emissions from 2024 to 2055 associated with the continued operation of Darlington following refurbishment is estimated to be 297 megatonnes of carbon dioxide, with an average reduction of 9.6 megatonnes per year, or the equivalent of two million cars.”

“Clean energy from nuclear power will continue to play a major role in Ontario’s future economic and environmental success, thanks in large part to the refurbishment of Darlington and the continued operations of Pickering,” said OPG President and CEO Jeff Lyash.

The Darlington station supplies about 20% of Ontario’s electricity at a cost that is lower than other forms of baseload generation. Refurbishing the station will ensure this source of clean energy is available for at least another 30 years and will also create significant economic benefits for the province, the utility said. OPG is also planning to continue to operate its Pickering station until 2024. A recent governmental “Speech From The Throne” indicated this will save Ontario’s electricity customers C$600 million and will also provide a clean energy source during the Darlington refurbishments. 

In the study, resource-specific GHG emission rates were used to estimate the total amount of GHGs emitted to meet Ontario’s energy requirements for three distinct scenarios:

  • Current energy production, with nuclear representing approximately 60% of Ontario’s energy requirements, until 2024 during a period of staggered refurbishments to the Darlington and Bruce nuclear stations.
  • Projected future scenario after 2024 with a reduction in nuclear capacity following the scheduled closure of the Pickering station and the completed refurbishment of the Darlington station. Under this scenario it was assumed that the necessary capacity lost with the closure of Pickering would be replaced by a combination of renewable sources (i.e., hydro, wind and solar PV) and natural gas.
  • Alternate projected future scenario after 2024 in the absence of the Darlington refurbishment resulting in a reduction in nuclear capacity associated with the closure of both the Pickering and Darlington stations. Under this scenario it was assumed that the necessary capacity lost with the closure of Pickering and Darlington would be replaced by a combination of renewable sources and natural gas.

The loss of nuclear capacity with the closure of Pickering after 2024 (Scenario 2), and the combined losses of capacity with the closure of both the Pickering and Darlington stations in an alternate future scenario (Scenario 3), result in an increase in total GHG emissions to 16 million tonnes (MT) and 26 MT CO2e in 2025, respectively, relative to the total GHG emissions of 12 MT CO2e in 2024 prior to the closure of these facilities and 7.2 MT CO2e under the current 2016 scenario.

Fluctuations in emissions in Scenarios 2 and 3 are largely attributed to planned refurbishments to the Bruce Station occurring until 2031. The total reduction in GHG emissions from 2024 to 2055 associated with the continued use of the Darlington Station following refurbishment is estimated to be 297 MT CO2e, with an average reduction of 9.6 MT CO2e per year. This is equivalent to removing approximately 2,000,000 cars from Ontario’s roads per year. A reduction of 9.6 MT CO2e per year also contributes to Ontario’s GHG emissions reduction targets under Ontario’s Climate Change Mitigation and LowCarbon Economy Act, 2016, which calls for reductions from 1990 emissions levels (181.8 MT CO2e) of 15% in 2020, 37% in 2030, and 80% in 2050, representing reductions of 27, 67 and 145 MT CO2e, respectively.

In Ontario, nuclear power is produced using Canada Deuterium Uranium (CANDU) Reactors which use unenriched uranium as fuel and deuterium oxide (or heavy water) as a coolant and moderator. There are currently 18 CANDU reactors operating in three facilities in Ontario including: eight at the Bruce Power Generating Station, six in the OPG Pickering Generating Station, and four in the OPG Darlington Generating Station. The combined installed capacity for these reactors for 2016 is 11,295 MW, with a projected decrease in capacity to 9,852 MW by 2032. The reduced capacity is associated with the scheduled closure of the Pickering Station in 2024; however, staggered refurbishments to both the Darlington and Bruce Stations will maintain capacity from each of these facilities.

Ontario Power Generation said in an Aug. 12 quarterly financial report that the Darlington nuclear units are approaching their originally designed end-of-life. Refurbishment of the units is expected to extend the operating life of the station by approximately 30 years. In January 2016, the Darlington Refurbishment project transitioned from the planning phase to the execution phase. OPG has begun the preparation for the refurbishment of the first unit, Unit 2, and is on track to commence the unit’s refurbishment in the fourth quarter of 2016.

The Government of Ontario’s support for the Darlington Refurbishment project has been affirmed through the Minister of Energy’s announcement in January 2016 endorsing OPG’s plan to refurbish the four Darlington units. OPG plans to commence subsequent unit refurbishments after Unit 2 is successfully returned to service, and expects to seek the province’s concurrence prior to proceeding with subsequent unit refurbishments.

Once refurbished, Unit 2 is scheduled to be returned to service in the first quarter of 2020, at which time capital expenditures of approximately C$4.8 billion are planned to be placed in service. This includes expenditures incurred during the definition and planning phase of the project.

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.