Darlington Nuclear Generating Station

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Darlington Nuclear Generating Station
Darlington Nuclear Generating Station panorama2.jpg
Darlington Nuclear Generating Station is located in Ontario
Darlington Nuclear Generating Station
Location of Darlington Nuclear Generating Station in Ontario
Country Canada
Location Clarington, Durham Region, Ontario
Coordinates 43°52′22″N 78°43′11″W / 43.87278°N 78.71972°W / 43.87278; -78.71972Coordinates: 43°52′22″N 78°43′11″W / 43.87278°N 78.71972°W / 43.87278; -78.71972
Status Operational
Construction began 1981
Commission date 1990–93
Construction cost $14.4 billion CAD
Operator(s) Ontario Power Generation (OPG)
Nuclear power station
Reactor type CANDU
Thermal power station
Cooling source Lake Ontario
Power generation
Units operational
Nameplate capacity 3,512 MW
Darlington Unit 1-4 Capability (Capacity Factor), 2003-2011[1][2][3]

Darlington Nuclear Generating Station is a Canadian nuclear power station located on the north shore of Lake Ontario in Clarington, Ontario. The facility derives its name from the Township of Darlington, the former name of the municipality in which it is located.

The Darlington station is a large nuclear facility and comprises 4 CANDU nuclear reactors located on the northern shore of Lake Ontario, having a total output of 3,512 MWe (capacity net) when all units are online. It provides about 20 percent of Ontario's electricity needs, enough to serve a city of two million people.[4]

Construction and operation[edit]

The facility was constructed in stages between 1981–1993 by the provincial Crown corporation, Ontario Hydro. Unit 2 was brought online in 1990, Unit 1 in 1992, and Units 3 and 4 in 1993. In April 1999 Ontario Hydro was split into 5 component Crown corporations with Ontario Power Generation (OPG) taking over all electrical generating stations and which continues to operate the Darlington station. The Darlington reactors have been among the best performing in OPG's CANDU fleet, including a top year in 2008 in which the plant achieved a combined 94.5% capacity factor.[5]

After public hearings in December 2012, the Canadian Nuclear Safety Commission announced in February 2013 the renewal of Darlington's power reactor operating licence, for a period from March 1, 2013 until December 31, 2014.[6]

Cost overruns[edit]

To most Ontarians, the Darlington station is associated with the massive cost overruns incurred during its construction. The initial cost estimate for the station was $3.9 billion CAD in the late 1970s, which increased to $7.4 billion in 1981 when construction was started.[7] A year-long period of public hearings and study by an Ontario government all-party committee finished in 1986 with the decision to proceed with the project, which had then risen to $7 billion in actual and committed costs.[8] The final cost was $14.4 billion CAD, almost double the initial construction budget.[9] The project was adversely affected by declining electricity demand forecasts, mounting debt of Ontario Hydro, and the Chernobyl disaster which necessitated safety reviews in mid-construction. Each delay incurred interest charges on debt, while ultimately accounted for 70% of the cost overruns.[10] Inflation during 1977 to 1981 was 46 percent, according to Canada's Consumer Price index. In addition interest rates were running at 20 percent. A quarter of the costs were attributable to other errors. Improper choice of equipment and a six-month labour stoppage of electrical workers yielded some of these costs and delays.[11] Discussion of who is to blame for the costs and subsequent debts associated with Darlington often arise during provincial election campaigns, and are often mentioned in anti-nuclear literature.[12]

New build proposal[edit]

In 2006, OPG started the federal approvals process to build new nuclear units at the site of its Darlington Nuclear Station. The project proposal involved the construction and operation of up to four nuclear units, with capacity of up to 4,800 MW.

A request for proposals (RFP) process for design and construction resulted in bids from Areva NP, Westinghouse, and Atomic Energy of Canada Limited (AECL). In June 2009, the Government of Ontario put the RFP process on hold, citing unexpectedly high bids, and the uncertainty surrounding the future of the only compliant bidder (AECL).[13][14][15]

In August 2011, the three-member Joint Review Panel (mandated by the Ontario Ministry of the Environment and the Canadian Nuclear Safety Commission) released a report finding that the Darlington new build project would not result in any significant adverse environmental impacts (after taking into account mitigation measures). Following the report, the federal government approved the Environmental Assessment.[16]

In October 2013, the Ontario government declared that the Darlington new build project would not be a part of Ontario's long term energy plan, citing the high capital cost estimates and energy surplus in the province at the time of the announcement.[17]

The Darlington new build project is deferred on the long term energy plan meaning the option is still open to build two new nuclear reactors at Darlington.


Low and intermediate level waste from Darlington is stored at the Western Waste Management Facility (WWMF) 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 this low and intermediate level waste on lands adjacent to WWMF. Pending approvals and licensing by regulatory agencies, the DGR would commence construction in 2013 and operation in 2018.[18]

The Darlington Waste Management Facility provides dry storage for the used fuel from Darlington, after an initial period in a water-filled storage bay. The facility was opened in 2007, reportedly on schedule and on budget.[19] The Nuclear Waste Management Organization is seeking a site in Canada for a permanent repository for used fuel from all of Canada's nuclear reactors.

Awards and recognition[edit]

2011: In December 2011 Darlington achieved 12 million hours without a lost time injury [20]

2009: William H. Howard Conservation, Education and Outreach Award (Wildlife Habitat Council) [21]

2008: International Corporate Habitat of the Year Award (Wildlife Habitat Council) [22]

2007: Performance Improvement Award (Institute of Nuclear Power Operators) [23]

2007: 20th Anniversary Signatures of Sustainability Award (Wildlife Habitat Council)[24]

2005: International Corporate Habitat of the Year Award (Wildlife Habitat Council) [25]


On December 21, 2009 the Darlington nuclear station saw workers mistakenly release around 200,000 litres of water containing trace amounts of radioactive isotope tritium into Lake Ontario. The water came from a storage tank and was not coming from the plant's running systems. The spilled water contained 0.1 per cent of the plant's allowable monthly release of tritium. .[26]

See also[edit]


  1. ^ "Report on 2008 Performance" (PDF). Retrieved 2013-10-26. 
  2. ^ "OPG 2010 Annual Report" (PDF). Retrieved 2013-10-26. 
  3. ^ "OPG 2011 Annual Report" (PDF). Retrieved 2013-10-26. 
  4. ^ "Darlington Nuclear". Retrieved 2009-02-10. 
  5. ^ Ferguson, Rob (9 Feb 2010). "'Tune-up' for Pickering, Overhaul at Darlington". Toronto Star. Retrieved 2010-02-10. 
  6. ^ "CNSC Renews OPG’s Darlington Nuclear Generating Station Operating Licence (revised)". Retrieved 2013-10-26. 
  7. ^ http://www.nuclearfaq.ca/cnf_sectionC.htm#SectionC
  8. ^ William Walker. "Ontario to complete huge nuclear plant." The Toronto Star, August 21, 1986.
  9. ^ Canadian Press: "Darlington price tag rises to $14.4 billion", The Toronto Star, March 4, 1993.
  10. ^ http://www.nuclearfaq.ca/cnf_sectionC.htm#darlington
  11. ^ http://www.magma.ca/~jalrober/CANcostb.htm
  12. ^ CBC News http://www.cbc.ca/ontariovotes2003/features/power_091703.html.  Missing or empty |title= (help)
  13. ^ "Darlington plans on hold". World Nuclear News. 29 June 2009. Retrieved 2009-07-16. 
  14. ^ Hamilton, Tyler (July 14, 2009). "$26B cost killed nuclear bid". Toronto Star. Retrieved 2009-07-16. 
  15. ^ Lawson, Don (February 2012). "CANDU at Darlington: Securing Jobs and Energy for the New Economy" (PDF). CCRE Commentary. Retrieved 2013-10-26. 
  16. ^ "Darlington New Build Project Overview". Retrieved 2013-10-26. 
  17. ^ ""Ontario nixes building two nuclear reactors" - Global News". Retrieved 2013-10-26. 
  18. ^ "OPG's DGR". Retrieved 2011-04-10. 
  19. ^ ""News from Ontario Power Generation", Nov 2, 2007" (PDF). Retrieved 2010-10-30. 
  20. ^ "OPG "POWERNews", vol. 14, issue 1" (PDF). Retrieved 2013-10-26. 
  21. ^ "OPG 2010 Sustainable Development Report" (PDF). Retrieved 2013-12-28. 
  22. ^ "OPG 2009 Sustainable Development Report" (PDF). Retrieved 2013-10-26. 
  23. ^ ""News from Ontario Power Generation", Dec 4, 2007" (PDF). Retrieved 2013-10-26. 
  24. ^ "OPG 2009 Sustainable Development Report" (PDF). Retrieved 2013-10-26. 
  25. ^ "OPG News Release, November 30, 2005". Retrieved 2013-10-26. 
  26. ^ "Nuclear plant spills tritium into lake" The Toronto Star. Author Jesse McLean.

External links[edit]