Refurbished Candus make headway towards restart

25 May 2023

Fuel loading has been completed at Bruce 6, keeping the project on track to resume operation later this year. Meanwhile, Canada's nuclear regulator has given the go-ahead for Ontario Power Generation (OPG) to restart Darlington 3.

Darlington 3 reactor face (Image: OPG)

Canadian Nuclear Safety Commission (CNSC) Executive Vice-President and Chief Regulatory Operations Officer Ramzi Jammal notified OPG by a letter dated 20 May that the regulator had concluded that OPG has met all its requirements for the removal of the second regulatory hold point for the project, allowing the refurbished reactor to leave the so-called guaranteed shutdown state, or GSS. "OPG may now proceed with surrendering GSS to restart the refurbished reactor at low power for testing and verification," Jammal said.

This follows the regulator's removal of the first hold point last December, allowing OPG to proceed with fuel loading at the reactor. Hold points are mandatory checkpoints where CNSC approval is required before the licensee can move on to the next stage of the process to return the unit to operation. Two further regulatory hold points remain before Darlington 3 can reach criticality and return to service.
 
Unit 3 is the second of four Candu reactors at the site to undergo refurbishment in a project with a 10-year execution phase, following unit 2 which returned to service in April 2020. Refurbishment of Darlington 3 began in September that year and is slated for completion in the first quarter of 2024. Refurbishment of unit 1 began in February this year, with completion expected in the second quarter of 2025, with refurbishment of Darlington 4 scheduled to begin in the third quarter of 2023.

Bruce fuel loading

Bruce Power announced that fuel loading at Bruce 6 has now been completed ahead of schedule. This follows CNSC's removal of the first regulatory hold point for that project on 10 May.

"Operations and Maintenance crews loaded 5,760 fuel bundles into the reactor core, safely completing the task ahead of schedule. Each fuel bundle contains 37 fuel rods, which are packed with Canadian-made uranium oxide pellets from Bruce Power partner Cameco. One bundle produces clean electricity that is equivalent to 400,000 kg of coal or 400,000 cubic metres of natural gas," the company said.

The unit is the first of six at the Ontario site to undergo refurbishment between 2020 and 2033. Bruce 3 became the second unit to begin the process - referred to as Major Component Replacement, or MCR - in March this year when it was taken offline for defueling.

The multi-billion dollar refurbishment projects ensure a further 30 years of operation for each Candu reactor.

Ontario urged to 'seize the moment' for new nuclear

24 May 2023

As a team at Ontario Tech University launches a new "Ontario-centric" research project to evaluate the economics and environmental impacts of low-carbon energy technologies including small modular reactors (SMRs), a new report from Canadians for Nuclear Energy says the province should "seize the moment" by building new Candu technology now.

FEAS researchers Jennifer McKellar, Kirk Atkinson and Xianke Lin, pictured in the university's Energy Research Centre (Image: Ontario Tech University)

Ontario is poised for rapid growth in electricity demand but does not have the capacity to meet it, grassroots non-profit organisation Canadians for Nuclear Energy finds in The Case for CANDU. "Homegrown" Candu reactor technology "is far ahead of other options in terms of local economic benefit, fuel security, project risk mitigation, and a proven track record of success", the report finds, and a "window of opportunity" created by reactor refurbishment projects that are already under way "offers a smooth onramp to new builds".
 
Candu pressurised heavy water reactors offer the lowest risk and highest benefit large nuclear option for Canada, the organisation argues. "Lowering project risk are decades of construction and maintenance experience, a fully developed supply chain and trained workforce, proven economics, and ongoing success with new-build-scale refurbishments. Meanwhile, decades of affordable power, uninterrupted fuel supply, successful exports, local jobs, community benefit, and a track record of decarbonisation prove that CANDU will meet the strictest criteria for new supply once built and will continue to do so for generations," it says.
 
Under current policy, Ontario's Independent Electricity System Operator (IESO) expects demand to increase by 60 TWh per year by 2043, enough to require adding ten new Candu reactors to the existing fleet of 18, the report finds. The province should consider building new Candu capacity alongside the planned BWRX-300 SMR at the Darlington New Nuclear Site, as well as beginning site development to support ten new Candu units, it recommends.
 
"Ontario faces energy challenges for which it has a proven solution and the opportunity to act," Canadians for Nuclear Energy President Chris Keefer said. "The pieces are in place. All that remains is to take the first step. To secure affordable energy for present and future generations, let's seize the moment and build new CANDU nuclear now."

The organisation has launched a petition urging the Government of Ontario to take action, including amongst other things by developing new sites for Candu construction, exploring the placement of two new Candu units at the Darlington New Nuclear Site, and seeking federal government support for future Candu projects.

SMR study

"No energy technology is inherently perfect: there are always going to be pros and cons," Jennifer McKellar, associate professor at Ontario Tech University's Faculty of Engineering and Applied Science (FEAS) said as the university announced the start of its study on the environmental impact of low-carbon electricity generation. The two-year investigation, jointly funded and supported by Ontario Power Generation (OPG) and not-for-profit organisation Mitacs, will apply life cycle assessment to consider all the impacts of technologies including lithium-ion battery technologies, SMRs, solar photovoltaics and wind turbines.
 
"For example, solar photovoltaics (PV) do not create carbon dioxide emissions during actual electricity generation, but the land requirements for their deployment can be significant. Similarly, both PV panels and wind turbines require critical minerals. It is important that we have a complete picture," McKellar, one of the project leaders, said.
 
Life cycle assessment considers impacts from the extraction of raw resources through to the final management of all waste, and this study will be one of the first to undertake such a comprehensive analysis for an SMR, Kirk Atkinson, director of the university's Centre for SMRs and an associate professor at FEAS, said. "Although we have a good handle on what SMR environmental performance will look like, this study will examine the details," he added.
 
"Our collaborative study with OPG and Mitacs Accelerate will be unique in that the analysis is an Ontario-specific examination of these four technologies, simultaneously," FEAS Assistant Professor Xianke Lin said. "This means we will be able to compare across technologies in a way that would not be possible if all four technologies were studied separately by four different researchers. This ensures a consistent and level playing field."

Researched and written by World Nuclear News