Pickering Nuclear Generating Station


Pickering Nuclear Generating Station is a Canadian nuclear power station located on the north shore of Lake Ontario in Pickering, Ontario. It is one of the oldest nuclear power stations in the world and Canada's third-largest, producing about 16% of Ontario's power and employing 3,000 workers.[3]

Pickering Nuclear Generating Station
Pickering Nuclear Plant.jpg
Unit 4 at the Pickering plant, facing East
LocationPickering, Durham Region, Ontario
Coordinates43°48′42″N 79°03′57″W / 43.81167°N 79.06583°W / 43.81167; -79.06583Coordinates: 43°48′42″N 79°03′57″W / 43.81167°N 79.06583°W / 43.81167; -79.06583
Construction began1966
Commission dateUnit 1: July 29, 1971
Unit 2: December 30, 1971
Unit 3: June 1, 1972
Unit 4 on June 17, 1973
Unit 5: May 10, 1983
Unit 6: February 1, 1984
Unit 7: January 1, 1985
Unit 8: February 28, 1986 [1]
Decommission date28 May 2007 (A2)
31 Oct 2008 (A3)
Construction cost$716 million CAD (A station)
$3.84 billion CAD (B station)
Owner(s)Ontario Power Generation (OPG)
Operator(s)Ontario Power Generation (OPG)
Nuclear power station
Reactor typeCANDU PHWR
Reactor supplierAECL
Cooling sourceLake Ontario
Thermal capacity6 × 1744 MWth
Power generation
Units operational2 × 515 MWe (NET A 1–4)
2 × 516 MWe (NET B 6–8)
1 × 522 MWe (NET B 7)
1 x 530 MWe (NET B 5)
Make and model2 × CANDU 500A
4 × CANDU 500B
Units decommissioned2 × 515 MW
Nameplate capacity3114 MW
Capacity factor73.85% (lifetime)
87.07% (2019)
Annual net output23,600 GW·h (2019) [2]
External links
WebsitePickering Nuclear
CommonsRelated media on Commons

Located at the Pickering station until October 2019 was a single 1.8 MWe wind turbine named the OPG 7 commemorative turbine. The turbine was dismantled in stages during October 2019 [4]

Reactor codificationEdit

The reactors can be classified as follows:


  • PICKERING A 2 (Safe Shutdown state, defuelled)
  • PICKERING A 3 (Safe Shutdown state, defuelled)




The site was once Squires Beach located west of Duffins Creek. The facility was constructed in stages between 1965 and 1986[5] by the provincial Crown corporation, Ontario Hydro, with significant completion of Station A scheduled for 1971.[6] In April 1999, Ontario Hydro was split into five component Crown corporations with Ontario Power Generation (OPG) taking over all electricity generating stations.[7] OPG continues to operate the Pickering station.[8]

The Pickering station is one of the larger nuclear facilities in the world[9][circular reference], comprising six operating CANDU nuclear reactors with a total output of 3,100 MW when all units are on line, and two non-operating units currently shut down in safe storage.[8] The facility is connected to the North American power grid via numerous 230 kV and 500 kV transmission lines.[10]

The facility was operated as two distinct stations, Pickering A (Units 1 to 4) and Pickering B (Units 5 to 8) until 2011.[11] While primarily administrative in nature, the division was not wholly artificial, as there are some distinct differences in design between the two groups of stations. (Example: The Pickering A units employ a moderator dump as a shutdown mechanism,[12] a feature not found in Pickering B, which instead uses what is called an over-poisoned reaction guaranteed shutdown.[13]) There are, however, a number of systems and structures in common between the two stations; the most notable of these is the shared vacuum building, a negative pressure containment system.[14] The operation of Pickering A and B was unified in 2010,[15] to reduce costs now that Pickering A Units 2 and 3 are shut down in safe storage.

Partial shutdownEdit

On December 31, 1997 the four Pickering A reactors were shut down by Ontario Hydro and placed in lay up, suspending work on upgrades to the shutdown system. Ontario Hydro committed to restarting the units, but the project underwent long delays and large cost over-runs.

Premier Mike Harris asked former federal energy Minister Jake Epp to study and make recommendations on the problems with the Pickering restart. The review panel was established in May 2003.

Unit 4 was refurbished and then restarted in Sept. 2003. The election of the Ontario Liberal Party in October 2003 delayed action on the Epp report. In late 2003, the new government fired the top three executives of OPG for botching the Unit 4 restoration, which was years late and millions of dollars over budget.[16]

Mr. Epp and the Pickering A Review Panel released their report in December 2003,[17] which acknowledged the large cost over-runs and delays, attributing blame to bad management. The Epp Review estimated the cost of restarting the remaining three reactors at $3 – 4 billion and supported the continuation of the project.

The government of Dalton McGuinty appointed Epp to the Ontario Power Generation Review headed by John Manley to examine the future role of Ontario Power Generation (OPG) in the province's electricity market, examine its corporate and management structure, and decide whether the public utility should proceed with refurbishing three more nuclear reactors at the Pickering nuclear power plant. The report recommended proceeding with the restart of Pickering “A” reactors 1, 2, and 3, sequentially. The report argued that the restart of units 2 and 3 would be contingent on whether “OPG will be able to succeed at the Unit 1 project."[18]

The McGuinty government accepted the OPG Review Committee's recommendation and allowed the refurbishment and restart of reactor 1, which still underwent cost over-runs and delays.[citation needed]

The anti-nuclear group Sierra Club of Canada criticized the 2004 OPG Review Committee report for not attributing any blame to the problems of nuclear technology, noting that there were no energy or environmental experts appointed to the panel.[19]

Numerous changes in executive-level staff and project management strategy were made for the follow-on project to refurbish Unit 1. The experience of refurbishing Pickering A Unit 1 was significantly different from Unit 4, with a much tighter adherence to schedule and budget.[citation needed] In August 2005, the OPG Board of Directors announced that Units 2 and 3 would not be refurbished due to specific technical and cost risks surrounding the material condition of these two units. Unit 1 was returned to service in November 2005, providing 542 MW of generating capacity for Ontario's electricity system.[citation needed]

The Pickering Nuclear Generating Station, viewed from the west. All eight reactors are visible, from 2.5km to 3.25km away.


Construction CostsEdit

Ontario Hydro estimated the construction cost for the four Pickering "A" units at $508 million in 1965. Actual cost was $716 million (in 1971 dollars). The 1974 estimated cost for the four Pickering "B" units was $1.585 billion. Final cost was $3.846 billion (1986 dollars).[20]

Refurbishment CostsEdit

According to Ontario's FAO, the cost for refurbishing Pickering A units deviated significantly from projections.[21]
- Pickering Unit 4 was slated to cost $460 million and ultimately ended up costing $1.25 billion.
- Pickering Unit 1 was slated to cost $210 million and ultimately ended up costing $1.00 billion.


The used nuclear fuel and some refurbishment waste generated by the plant sits on-site at the Pickering Waste Management Facility. All operational low and intermediate-level waste is transported to OPG's Western Waste Management Facility at the Bruce nuclear site near Kincardine, Ontario. OPG has proposed the construction and operation of a deep geologic repository for the long-term storage of low and intermediate level waste on lands adjacent to the Western Waste Management Facility.[22] The Nuclear Waste Management Organization is currently seeking a site for a potential repository for the used fuel from all Canadian nuclear reactors.


- On October 7, 1994, Pickering Unit 7 set the world record for continuous runtime at 894 days, a record that stood for 22 years. It was surpassed by Heysham 2 unit 8 in 2016, a facility located in the UK, owned by EDF.[23] This was subsequently surpassed by OPG's Darlington plant with Unit 1 running 1,106 consecutive days.[24]
- In 2019, Pickering set a site capacity factor record of 87.07%, producing 23.6TWh and putting it roughly on-par with the much newer Darlington and Bruce facilities.[2]


In January 2016, the Province of Ontario approved plans to pursue continued operation of the Pickering Nuclear Generating Station to 2024.[25]

OPG will work with the Ministry of Energy, the Independent Electricity System Operator and the Ontario Energy Board 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.[26] Extending Pickering's operation will ensure a reliable, clean source of base load electricity during refurbishment of the Darlington Nuclear Generating Station and the initial Bruce Nuclear refurbishments.[27]

Any plan to extend Pickering's life requires approval from the Canadian Nuclear Safety Commission (CNSC). OPG is currently working on a licence application to the CNSC for approval in 2018.

After operation of Pickering concludes, OPG will begin the longer term decommissioning process as refurbishment will not be pursued. The first step in the long term decommissioning process is to layup the reactors and place them into safe storage. Pickering staff will have future employment opportunities placing the Pickering units in a safe storage state, at the Darlington refurbishment and operations, or at the potential new build at Darlington.

OPG has begun planning for the station's end of commercial operations including the potential repurposing of the Pickering site location.[28]

OPG will proceed with a detailed planning phase for the mid-life refurbishment of the Darlington Nuclear Generating Station east of Toronto, with construction expected to start in 2016. The business decision to move forward with an investment in Darlington came after initial studies on the plant's condition operating performance returned positive results.

In January 2016, the Province of Ontario announced its decision to proceed with refurbishment of Darlington.[25]


A serious incident occurred on 1 August 1983. Pressure tube G16 in the Pickering A Unit 2 reactor developed a 2 metre long split. The reactor was safely shut down and the damage investigated. The cause was found to be the mis-location of annulus gas spacer springs which allowed the hot pressure tube to sag and touch the inside of the cold calandria tube leading to hydrogen enrichment of the cooler areas. This created a series of small cracks which linked up and caused the long rupture. There was some local fuel damage and the reactor was safely shut down by the operators with no increase in radioactive emissions. The eventual resolution was Large Scale Fuel Channel Replacement and all the pressure tubes were replaced in all Pickering A reactors. The new pressure tubes were supported by an improved design of the annulus gas spacer springs. Since then, careful monitoring of the location of the annulus gas spacer rings has been a significant part of routine reactor inspections.[29]

On December 10, 1994 there was a loss of coolant accident. It is said to be the most serious accident in Canadian history (June 2001) by The Standing Senate Committee on Energy, the Environment and Natural Resources. The Emergency Core Cooling System was used to prevent a meltdown.[30][31]

On March 14, 2011, there was a leak of 73 cubic metres of demineralized water into Lake Ontario from a failed pump seal. There was negligible risk to the public according to the Canadian Nuclear Safety Commission.[32]

2020 nuclear incident alertEdit

On January 12, 2020 at 7:24 a.m. ET, an emergency alert was issued via Alert Ready on all radio stations, television stations, television providers, and wireless networks in the province of Ontario, containing an advisory of an unspecified "incident" that had been reported and was being addressed at the plant. The alert stated that no immediate action was required for those within 10 kilometres (6.2 mi) of the plant. Approximately 40 minutes later, OPG issued a statement via Twitter that the alert had been sent in error, and a second emergency alert was issued at around 9:10 a.m. with a similar message cancelling the previous alert.[33][34]

Solicitor General Sylvia Jones stated that the alert was accidentally issued during a "routine training exercise" by Ontario's emergency operations centre. The incident prompted criticism from government officials, including MPP Peter Tabuns, Pickering mayor Dave Ryan, and Toronto mayor John Tory.[35]

The false alarm also prompted renewed interest in preparedness for actual nuclear accidents: OPG reported a surge in the sales of potassium iodide kits via its "Prepare to Be Safe" website between January 12 and 13, increasing from its monthly average of 100 to 200, to over 32,000. The website is applicable for those who live within 50 kilometres (31 mi) of the plant; per Canadian Nuclear Safety Commission (CNSC) requirements, OPG is required to distribute these pills to all residences within 10 kilometres (6.2 mi) of a nuclear facility.[36][37][38]

See alsoEdit


  1. ^ https://www.opg.com/document/preliminary-decommissioning-plan-for-pickering-generating-stations-a-b-pdf/
  2. ^ a b "Our story > Pickering Nuclear celebrates record-setting year". OPG. 2020-01-30. Retrieved 2021-11-29.
  3. ^ "Future of Pickering nuclear plant a hot topic in Durham Region".
  4. ^ "News > Removal of Pickering wind turbine – Sept. 30 to Nov. 8, 2019". OPG. 2019-09-27. Retrieved 2021-11-29.
  5. ^ https://www.pembina.org/reports/gp-betternever.pdf[bare URL PDF]
  6. ^ "Canadian Champion (Milton, ON), 5 Apr 1967, p. 5".
  7. ^ "A look at the long, complicated history of Ontario hydro".
  8. ^ a b "Nuclear power > Pickering Nuclear Generating Station". OPG. Retrieved 2021-11-29.
  9. ^ List of nuclear power stations
  10. ^ https://www.hydroone.com/abouthydroone/CorporateInformation/regionalplans/gtaeast/Documents/2016-Pickering-Ajax-Whitby-IRRP-Appendices.pdf[bare URL PDF]
  11. ^ McClearn, Matthew; Baum, Kathryn Blaze (16 January 2020). "Ontario government supports OPG proposal to operate Pickering nuclear station past planned 2024 closing". The Globe and Mail.
  12. ^ "The Use of Rod-Based Guaranteed Shutdown State in CANDU Reactors - Canadian Nuclear Safety Commission". Nuclearsafety.gc.ca. 2016-04-08. Retrieved 2021-11-29.
  13. ^ Urjan, R. "Rod-Based Guaranteed Shutdown States (RBGSS) implementation a..|INIS". Inis.iaea.org. Retrieved 2021-11-29.
  14. ^ "Pickering Nuclear Generating Station - Canadian Nuclear Safety Commission". Nuclearsafety.gc.ca. 3 February 2014. Retrieved 2021-11-29.
  15. ^ https://www.oeb.ca/oeb/_Documents/Decisions/dec_reasons_OPG_20141120.pdf[bare URL PDF]
  16. ^ Luciw, Roma (12 August 2005). "OPG cancels Pickering repairs". The Globe and Mail.
  17. ^ https://collections.ola.org/mon/7000/10317476.pdf[bare URL PDF]
  18. ^ Ontario Power Generation Review Committee, Transforming Ontario’s Power Generation Company, March 2004, p. 47
  19. ^ "The Sierra Club info". Sierra Club Canada. Archived from the original on 16 April 2004.
  20. ^ "Archived copy" (PDF). www.pembinafoundation.org. Archived from the original (PDF) on 4 April 2017. Retrieved 19 April 2022.{{cite web}}: CS1 maint: archived copy as title (link)
  21. ^ https://www.fao-on.org/web/default/files/publications/Nuc%20Refurb%20nov%202017/Nuclear-Refurb-EN.pdf[bare URL PDF]
  22. ^ "OPG's DGR". Retrieved 2011-04-11.
  23. ^ Larson, Aaron (2016-09-21). "New Record: Nuclear Power Plant Online for 940 Continuous Days". Powermag.com. Retrieved 2021-11-29.
  24. ^ "Darlington's Unit 1 heads into planned outage after record-breaking run". OPG. 2021-02-05. Retrieved 2022-01-13.
  25. ^ a b Ontario Moving Forward with Nuclear Refurbishment at Darlington and Pursuing Continued Operations at Pickering to 2024. Ontario Government news release, Jan 11, 2016
  26. ^ "Ontario Power Generation | Pickering Nuclear". www.opg.com. Retrieved 2016-06-28.
  27. ^ "Ministry of Energy » Ontario's Long-Term Energy Plan". www.energy.gov.on.ca. Retrieved 2016-06-28.
  28. ^ Repurposing Pickering, Ontario Power Generation website, Retrieved June 27, 2016
  30. ^ "Nuclear Threat in the Eastern Mediterranean" David H. Martin, June 2000, Page 10 (or page 17 of 106) Archived 2014-10-13 at the Wayback Machine
  31. ^ "Pickering A Shutdown and Rehabilitation: A Brief History" page 4 (or page 11 of 51)
  32. ^ Pickering Nuclear plant reports water leak, CBC News, March 16 2011
  33. ^ "Ontario government apologizes for alert about Pickering nuclear plant incident sent 'in error'". CBC News. 2020-01-12. Retrieved 2020-01-12.
  34. ^ "Pickering Nuclear Generating Station emergency alert issued in error, OPG says". Global News. Retrieved 2020-01-12.
  35. ^ Austen, Ian (2020-01-12). "Ontario Warned of a Nuclear 'Emergency,' Then Said Never Mind". The New York Times. ISSN 0362-4331. Retrieved 2020-01-12.
  36. ^ "Iodide pills protect you in a nuclear disaster. So, why didn't more people have them before the Pickering scare?". Toronto Star. 20 January 2020. Retrieved 2020-01-21.
  37. ^ "Orders for potassium iodide pills surge after false alarm at Pickering nuclear power plant". Toronto Star. 14 January 2020. Retrieved 2020-01-21.
  38. ^ "Over 32,000 potassium iodide pills ordered in 2 days after Pickering nuclear power plant alert error". CBC News. January 14, 2020. Retrieved January 20, 2020.

External linksEdit

  • Ontario Power Generation
  • Google maps satellite image