Editing Heavy water (section)

===Canada===
As part of its contribution to the Manhattan Project, Canada built and operated a {{convert|1000|to|1200|lb|kg}} per month (design capacity) electrolytic heavy water plant at [[Trail, British Columbia]], which started operation in 1943.<ref>{{cite report 
| title = Manhattan District History, Book III, The P-9 Project
| url = https://www.osti.gov/includes/opennet/includes/MED_scans/Book%20III%20-%20The%20P-9%20Project.pdf
| date = 8 April 1947
| publisher = [[United States Department of Energy]]
| page = 99
| access-date = 16 February 2019}} The original design production was 1000 lbs./month, later increased to 1200 lbs./month. Maximum production was 1330 lbs./month.
</ref>

The [[Atomic Energy of Canada Limited]] (AECL) design of power reactor requires large quantities of heavy water to act as a [[neutron moderator]] and coolant. AECL ordered two heavy water plants, which were built and operated in [[Atlantic Canada]] at [[Glace Bay]], [[Nova Scotia]] (by Deuterium of Canada Limited) and [[Point Tupper, Richmond County]], Nova Scotia (by Canadian General Electric). These plants proved to have significant design, construction and production problems. The Glace Bay plant reached full production in 1984 after being taken over by AECL in 1971.<ref>{{cite book |last1=MacInnis |first1=Roland |title=Hell And Heavy Water |date=2018 |publisher=Roland MacInnis |isbn=978-1720808770 |pages=38, 54 |edition=1}}</ref> The Point Tupper plant reached full production in 1974 and AECL purchased the plant in 1975.<ref>{{cite book |last1=Davies |first1=Stanley |title=Is Making Heavy Water Painful? |date=2023 |publisher=Stanley M. Davies |isbn=9798377591016 |pages=218, 232 |edition=1 |url=https://www.amazon.com/dp/B0BXHQFT9T |access-date=30 January 2024}}</ref> Design changes from the Point Tupper plant were carried through as AECL built the Bruce Heavy Water Plant ({{Coord|44.1854|-81.3618|type:landmark_region:CA|name=Bruce Heavy Water Plant|display=inline}}),<ref>Google Earth</ref> which it later sold to [[Ontario Hydro]], to ensure a reliable supply of heavy water for future power plants. The two Nova Scotia plants were shut down in 1985 when their production proved unnecessary.

The [[Bruce Nuclear Generating Station|Bruce Heavy Water Plant]] (BHWP) in [[Ontario]] was the world's largest heavy water production plant with a capacity of 1600 tonnes per year at its peak (800 tonnes per year per full plant, two fully operational plants at its peak). It used the [[Girdler sulfide process]] to produce heavy water, and required 340,000 tonnes of feed water to produce one tonne of heavy water. It was part of a complex that included eight [[CANDU reactor]]s, which provided heat and power for the heavy water plant. The site was located at [[Douglas Point]]/[[Bruce Nuclear Generating Station]] near Tiverton, Ontario, on [[Lake Huron]] where it had access to the waters of the [[Great Lakes (North America)|Great Lakes]].<ref name="CSR on BHWP decommissioning">{{cite web|url=https://www.ceaa-acee.gc.ca/EADDB84F-docs/report_e.pdf| title=Bruce Heavy Water Plant Decommissioning Project |publisher=Canadian Nuclear Safety Commission|access-date=21 February 2018|date=March 2003}}</ref>

AECL issued the construction contract in 1969 for the first BHWP unit (BHWP A). Commissioning of BHWP A was done by Ontario Hydro from 1971 through 1973, with the plant entering service on 28 June 1973, and design production capacity being achieved in April 1974. Due to the success of BHWP A and the large amount of heavy water that would be required for the large numbers of upcoming planned CANDU nuclear power plant construction projects, Ontario Hydro commissioned three additional heavy water production plants for the [[Bruce Nuclear Generating Station|Bruce site]] (BHWP B, C, and D). BHWP B was placed into service in 1979. These first two plants were significantly more efficient than planned, and the number of CANDU construction projects ended up being significantly lower than originally planned, which led to the cancellation of construction on BHWP C & D. In 1984, BHWP A was shut down. By 1993 Ontario Hydro had produced enough heavy water to meet all of its anticipated domestic needs (which were lower than expected due to improved efficiency in the use and recycling of heavy water), so they shut down and demolished half of the capacity of BHWP B. The remaining capacity continued to operate in order to fulfil demand for heavy water exports until it was permanently shut down in 1997, after which the plant was gradually dismantled and the site cleared.<ref name="BHWP performance">{{cite book|last1=DAVIDSON|first1=G. D.|title=Separation of Hydrogen Isotopes|volume=68|date=1978|publisher=American Chemical Society|isbn=978-0841204201|pages=27–39|chapter=Bruce Heavy Water Plant Performance|doi=10.1021/bk-1978-0068.ch002|series=ACS Symposium Series}}</ref><ref name="CHWP 1970–1980">{{cite web|last1=Galley|first1=M.R.|last2=Bancroft|first2=A.R.|title=Canadian Heavy Water Production - 1970 TO 1980|url=https://www.iaea.org/inis/collection/NCLCollectionStore/_Public/13/680/13680421.pdf|access-date=21 February 2018|date=October 1981}}</ref>

AECL is currently researching other more efficient and environmentally benign processes for creating heavy water. This is relevant for CANDU reactors since heavy water represented about 15–20% of the total capital cost of each CANDU plant in the 1970s and 1980s.<ref name="CHWP 1970–1980" />