Ontario Power kicks off Darlington nuclear refurbishment project

Ontario Power Generation (OPG) said Oct. 14 that it is starting Canada’s largest clean energy project, which is the refurbishment of the Darlington Nuclear Generating Station located east of Toronto.

“Refurbishment of Darlington will ensure emissions-free nuclear continues to be Ontario’s single largest source of power. The project will create up to 11,800 jobs annually and contribute nearly $15 billion to Ontario’s economy.” said Glenn Thibeault, Ontario Minister of Energy.

“This project is an investment in Ontario’s future. It benefits communities across the province, it provides clean, safe and reliable power and will help moderate customer prices,” said Jeff Lyash, OPG’s President and CEO. “I’ve been involved in a lot of major projects over the years and I can confidently say, I’ve never seen one that has had this amount of rigorous preparation and is this poised for success.”

The Darlington refurbishment will permanently boost the Ontario economy, according to the results of research conducted by the Conference Board of Canada and presented to OPG.

“The boost to economic activity would have far-reaching and long-term stimulative effects on the Ontario economy,” said Pedro Antunes, Executive Director and Deputy Chief Economist, the Conference Board of Canada. “The operational expenditures associated with Darlington through 2055 will lift employment by roughly 555,000 person-years in Ontario over the life of the station, with Darlington serving as a critical source of job creation for Ontarians, both within and outside the utilities industry.”

A recent report released by Intrinsik Environmental Sciences Inc. says “continued operations of the Darlington Nuclear Generating Station will remove the equivalent of two million cars a year from Ontario’s roads.”

OPG is also planning to continue to operate its Pickering Nuclear Generating Station until 2024. The recent “Speech from the Throne” indicated this will save Ontario’s electricity customers C$600 million, and provide a clean energy source of electricity when Darlington and Bruce Power nuclear units are offline for refurbishment.

The Darlington Nuclear Generating Station produces 20% of the province’s generation. The price for the electricity from the refurbished station is projected to cost about C8 cents a kilowatt hour. This is below prices for power from alternate sources of baseload power. The final price will be set by the Ontario Energy Board (OEB) after a full public process.

OPG said it will work with the Ministry of Energy, the Independent Electricity System Operator and the OEB to pursue continued operation of the Pickering station to 2024. All six units would operate until 2022; two units would then shut down and four units would operate to 2024. Technical studies show that Pickering can be safely operated to 2024.

Darlington is a four-unit station with a total capacity of 3,512 MW.

OPG said it has put in years of detailed planning, built a state-of-the-art training facility, assembled an excellent team, and partnered with top companies from across Ontario. Detailed planning commenced in 2010 and concluded at the end of 2015. A state-of-the-art, full-size reactor mock-up was built to test specialized tools and train workers; § Engineering was completed before field execution starts; § Site preparations focused on maximizing worker productivity.

OPG has a project management team with extensive refurbishment experience from Canada and around the world. Team members include those seconded to Atomic Energy of Canada Ltd. to work on the Point Lepreau refurbishment project in New Brunswick. OPG is continuing to acquire talent from other major projects to enhance the project management team and develop future leaders.

Refurbishing each of Darlington Nuclear Generating Station’s four reactors involves a number of steps.

  • Shutdown of the Reactor – The first major activity during the refurbishment will be to shut down the reactor. At this time, systems not required for an extended period are placed into a safe state referred to as lay-up.
  • Removal of Fuel and Heavy Water – The fuel will be removed from the reactor and will be placed in the fuel bays. Once the reactor fuel is removed from the reactor, heavy water will be drained from the system and transferred to an appropriate storage facility. The heavy water will be processed and available for reactor use when the outage is completed.
  • Islanding the Refurbishment Unit from the Operating Units – Once the reactor undergoing refurbishment has been defueled, it will be separated (islanded) from the other operating units. This is done by putting up physical barriers to delineate the refurbishment island from the operating reactors.
  • Replacement of Reactor Components – The reactor components will be restored or replaced. This includes removing and replacing 480 fuel channel assemblies and 960 inlet and outlet feeders per reactor. Removing and replacing the reactor components is the critical part of the outage. OPG has applied lessons learned from past refurbishment efforts. This includes developing intensive personnel training and tool testing programs in the full-scale reactor mock-up.
  • Turbine and Steam Generators – A majority of the turbine generator systems and auxiliary systems will be disassembled and rebuilt or replaced. OPG has concluded the steam generators will remain fit for service over the life extension period and will not require replacement. The steam generator tubes and parts will be inspected, inspection nozzles will be installed and the steam generators will be cleaned to improve heat transfer.
  • Balance of Plant Repair and Maintenance – The remaining scope of work is being carried out to maintain or improve the safety and reliability of the station to the post-refurbishment end of life. The scope of work includes: work on nuclear systems, such as the primary heat transport system and the reactor regulating systems; and work on conventional systems, such as the low pressure service water system and the fire protection system.
  • Return to Service of Reactors – Return to service involves returning the reactor to commercial operation, and includes demonstrating the work meets specified requirements. Return to service covers a range of activities from completing the installation work to achieving 100% reactor power.
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.