{"id":615562,"date":"2026-04-20T01:30:14","date_gmt":"2026-04-20T01:30:14","guid":{"rendered":"https:\/\/www.newsbeep.com\/ca\/615562\/"},"modified":"2026-04-20T01:30:14","modified_gmt":"2026-04-20T01:30:14","slug":"atkinsrealis-groups-monark-nuclear-reactor-misses-output-target","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ca\/615562\/","title":{"rendered":"AtkinsR\u00e9alis Group\u2019s Monark nuclear reactor misses output target"},"content":{"rendered":"

AtkinsR\u00e9alis Group Inc.\u2019s ATRL-T<\/a> Monark nuclear power reactor, which had aimed to produce substantially more electricity than previous Candu reactors, will actually produce slightly less, according to the Canadian Nuclear Safety Commission.<\/p>\n

The Monark has been marketed by its designer, AtkinsR\u00e9alis Group Inc., as boasting a electricity generation capacity of 1,000 megawatts. However, the CNSC recently updated its website<\/a> to reflect a much lower capacity as the regulator begins a preliminary review of the Monark.<\/p>\n

\u201cAs the design has progressed, AtkinsR\u00e9alis has further defined the power of the reactor,\u201d wrote CNSC spokesperson Braeson Holland in a statement confirming the new output, which she said is around 850 megawatts.<\/p>\n

AtkinsR\u00e9alis disputed that, asserting that its submission to the CNSC was for a 925-megawatt reactor. In either case, the Monark\u2019s lower-than-promised output could represent a problem as it competes head-to-head with much larger reactors. <\/p>\n

Since the last Candus were built decades ago, the reactor market has continued a longstanding trend toward ever-larger units. According to data from Mycle Schneider Consulting<\/a>, construction began on 73 reactors worldwide since 2016. Their average output approached 1,100 megawatts; only four, all in India, fell in the range between 800 and 999 megawatts. <\/p>\n

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When AtkinsR\u00e9alis announced the Monark in November, 2023, it claimed the reactor would boast \u201cthe highest output of any CANDU technology at 1,000 megawatts.\u201d It assembled a team with hundreds of members to design it.<\/p>\n

Taxpayer support followed. In March, 2025, the federal government announced it had entered into an agreement with AtkinsR\u00e9alis with the intention of loaning the company more than $300-million over four years to finance half of the Monark\u2019s development. (Natural Resources Canada spokesperson Miriam Galipeau said that agreement was subject to further negotiations and due diligence, and that no loan has been granted yet.)<\/p>\n

That same month, Patrick Reed, the project\u2019s technical director, said during a presentation that one-third of the Monark\u2019s higher output would be achieved through \u201cimprovements on the secondary side,\u201d a reference to the portion of the plant where water is turned into steam to drive turbines. Also, the Monark\u2019s steam generators would be much larger than those of previous Candus, increasing the amount of heat that could be extracted from the reactor core.<\/p>\n

It\u2019s unclear how the Monark\u2019s diminished output might affect its prospects as AtkinsR\u00e9alis pursues orders from Ontario\u2019s two largest power utilities. Ontario Power Generation Inc. proposes to build a new nuclear plant dubbed Wesleyville with a capacity of up to 10,000 megawatts; Bruce Power LP is planning a new station at its existing Bruce facility, featuring up to 4,800 megawatts.<\/p>\n

OPG reported in a January regulatory filing that it had considered the Monark, Westinghouse Electric Co.\u2019s AP1000 and Electricit\u00e9 de France\u2019s European Pressurized Reactor (EPR) for Wesleyville. (It also contemplated the BWRX-300, a much smaller reactor it is already building at its Darlington station.) Bruce Power has not revealed which reactors made its short list. Both utilities denied interview requests for this story.<\/p>\n

AtkinsR\u00e9alis, Turkish company to explore building Candu reactors<\/a><\/p>\n

The Monark\u2019s competitors are substantially larger. The AP1000, which Westinghouse is aggressively marketing in Canada, puts out 1,100 megawatts. France\u2019s EPR is even larger, with a gross output of around 1,600 megawatts. Korea Electric Power Corp.\u2019s APR-1400 reactor, sometimes raised as a dark horse for deployment in Canada, puts out 1,400 megawatts.<\/p>\n

Reactor selection for Ontario\u2019s plants, which is being co-ordinated by the province\u2019s government, could strongly influence other Canadian utilities that are considering building nuclear plants. On Thursday, Saskatchewan\u2019s government announced that its Crown utility, SaskPower, had entered into an agreement with Bruce Power to access expertise as it evaluates large reactors. Separately, Energy Alberta, which seeks to build large reactors in Alberta, announced it had entered into its own agreement to access Bruce Power\u2019s expertise.<\/p>\n

Output is just one of many considerations when buying a reactor; as a Canadian design, the Monark might enjoy a measure of home-court advantage. OPG and Bruce Power already possess extensive experience with Candus. And Ontario Energy Minister Stephen Lecce has also placed strong emphasis on local supply chains and domestic economic benefits; any foreign-designed reactor would likely offer less on that front.<\/p>\n

Chris Gadomski, a nuclear energy analyst with BloombergNEF, said the Monark\u2019s size will be of secondary importance to its cost. If its capital cost per megawatt is competitive, then its smaller size \u201cshouldn\u2019t make much difference,\u201d he said. It might even be more attractive to certain utilities, he added, because disconnecting one from the grid for maintenance or other reasons would be less disruptive.<\/p>\n

AtkinsR\u00e9alis spokesperson Daniela Pizzuto said the Monark will be \u201ca close replication\u201d of the Candu 850 reactors at Darlington, which were built in the 1980s and early 1990s. She added that the Monark\u2019s lower-than-promised output reflects the company\u2019s intention to duplicate the Darlington reactor\u2019s design as closely as possible while avoiding risks associated with a first-of-a-kind reactor.<\/p>\n

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Ibrahim Attieh, a reactor physicist who worked on Candu designs for many years, had warned The Globe and Mail more than two years ago that the Monark was unlikely to meet the 1,000-megawatt target, owing to technical decisions made in the early stages of its design. <\/p>\n

Atomic Energy of Canada Ltd. (which AtkinsR\u00e9alis purchased from the federal government in 2011) previously attempted to update the Candu 850 in the 1990s with a 935-megawatt version called the Candu-9. Mr. Attieh said the Monark used many of the same strategies employed unsuccessfully to boost the Candu-9\u2019s output.<\/p>\n

He added that when Ontario Hydro built the province\u2019s original nuclear stations, it employed a massive contingent of experienced engineers, as did AECL. The work force available today is tiny by comparison, and far less experienced.<\/p>\n

\u201cCanada has failed to successfully design a nuclear reactor for the last 40 years,\u201d he wrote.<\/p>\n

The source of the disagreement between AtkinsR\u00e9alis and the CNSC regarding the Monark\u2019s output is unclear. Although electricity is the most important product from most nuclear plants, strictly speaking, reactors generate heat; thus, they are rated in megawatts thermal. The thermal output is generally three times higher than the plant\u2019s capacity to generate electricity, which is expressed in megawatts electric. That capacity is often further subdivided into \u201cgross\u201d and \u201cnet\u201d figures, the latter of which takes into account the substantial amount of electricity consumed by the plant itself. The plethora of different ways of measuring reactor output sometimes conjures confusion.<\/p>\n

Ms. Pizzuto clarified that the Monark will have a net output of 925 megawatts.<\/p>\n

With a file from Emma Graney<\/p>\n","protected":false},"excerpt":{"rendered":"AtkinsR\u00e9alis Group Inc.\u2019s ATRL-T Monark nuclear power reactor, which had aimed to produce substantially more electricity than previous…\n","protected":false},"author":2,"featured_media":615563,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[901,888,902,879,877,903,45,49,48,876,895,896,891,878,875,46,549,295,894,887,914,880,881,893,889,890,884,904,885,909,910,912,907,911,905,908,882,898,899,714,897,906,865,61,900,892,886,883,913],"class_list":["post-615562","post","type-post","status-publish","format-standard","has-post-thumbnail","category-business","tag-alberta","tag-arts-news","tag-bc","tag-breaking-news","tag-breaking-news-video","tag-british-columbia","tag-business","tag-ca","tag-canada","tag-canada-news","tag-canada-sports","tag-canada-sports-news","tag-canada-trafficcanada-weather","tag-canadian-breaking-news","tag-canadian-news","tag-economy","tag-education","tag-environment","tag-federal-government","tag-foreign-news","tag-globe-and-mail","tag-globe-and-mail-breaking-news","tag-globe-and-mail-canada-news","tag-government","tag-life-news","tag-lifestyle","tag-local-news","tag-manitoba","tag-national-news","tag-new-brunswick","tag-newfoundland-and-labrador","tag-northwest-territories","tag-nova-scotia","tag-nunavut","tag-ontario","tag-pei","tag-photos","tag-political-news","tag-political-opinion","tag-politics","tag-politics-news","tag-quebec","tag-sports-news","tag-technology","tag-travel","tag-trudeau","tag-us-news","tag-world-news","tag-yukon"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/615562","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/comments?post=615562"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/615562\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media\/615563"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media?parent=615562"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/categories?post=615562"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/tags?post=615562"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}