Nuclear Monitor #918
Brennain Lloyd and Susan O’Donnell
Introduction: CANDUs versus SMRs
Canada developed the CANDU reactor, fueled with natural uranium mined in Canada and cooled and moderated with heavy water. All 19 operating power reactors in Canada – 18 in Ontario on the Great Lakes and one in New Brunswick on the Bay of Fundy – are CANDU designs with outputs ranging from about 500 to 900 MWe.
It’s been more than 30 years since the last CANDU was completed and connected to the grid in Canada. Attempts to build new ones were halted over high projected costs, and CANDU exports have dried up. To keep itself alive, in 2018 the nuclear industry launched a “roadmap” to develop smaller reactors and kick-start new nuclear export opportunities.
From 2020 to 2023, the Canadian government funded six so-called “Small Modular Nuclear Reactor” (SMR) designs. Only one – Terrestrial Energy’s Integral Molten Salt Reactor (IMSR) design – is Canadian.
The six designs are not only unlike the CANDU but also different from each other. The fuels range from low-enriched uranium, TRISO particles and HALEU (High-Assay, Low-Enriched Uranium) to plutonium-based fuel, and the different cooling systems include high-temperature gas, molten salt, liquid sodium metal and heat pipes. One design – Moltex – requires a separate reprocessing unit to extract plutonium from used CANDU fuel to make fuel for its proposed SMR.
Only one of the grid-scale SMR designs seems plausible to be built – the GE Hitachi 300 MW boiling water reactor (BWRX-300) being developed at the Darlington nuclear site on Lake Ontario. This design uses low-enriched uranium fuel and is cooled by ordinary water. The Darlington site owner, the public utility Ontario Power Generation (OPG), is planning to build four of them.
Canada gave OPG a $970 million “low-interest” loan to help develop the BWRX-300 design. The other five SMR designs received considerably less federal funding, from $7 million to $50.5 million each, and most SMR proponents have been struggling to source matching funds. One design, Westinghouse’s off-grid eVinci micro-reactor, had early development costs funded by the U.S. military and now seems to have independent funding.
The Canadian Nuclear Laboratories (CNL) at Chalk River received more than $1.2 billion in 2023. CNL is operated by a private-sector consortium with two U.S. companies involved in the nuclear weapons industry and the Canadian firm Atkins-Réalis (formerly SNC Lavalin) which is also involved in almost every SMR project in Canada. CNL and Atomic Energy of Canada Limited are building an “Advanced Nuclear Materials Research Centre” at Chalk River, one of the largest nuclear facilities ever built in Canada, that will conduct research on SMRs.
Canada recently released a report suggesting that SMRs will be in almost all provinces by 2035, although most provincial electrical utilities have expressed no interest, and only Ontario, New Brunswick, Saskatchewan and Alberta are promoting SMRs. Alberta says it wants SMRs to reduce the GHG emissions generated in tar sands extraction.
SMR “project creep”
Proponents of most of the SMR designs keep changing the description of their projects. This is not unique to Canada, but is certainly apparent in Canada, and the regulator, the Canadian Nuclear Safety Commission (CNSC), aids and abets that practise for those SMRs in the review stream.
In the case of the BWRX-300 proposed for the Darlington site, the CNSC not only accepted a 2009 environmental assessment for very different reactors as a stand-in for the BWRX-300 but also is carrying out the current review as if for a single reactor. The nuclear regulator made this decision despite Ontario Power Generation very publicly stating its intent to construct four reactors in rapid succession at the Darlington site.
The proposed “Micro Modular Reactor” (MMR) for the Chalk River site in Ontario is another example of “project creep” and demonstrates just how flexible “scope of project” is in the domain of the CNSC.
Earlier this year, CNSC staff released a document outlining communications from the MMR proponent, Global First Power, describing significant project changes. The proponent wants to triple power output, and to operate with fuel enrichment levels from 9.75% (LEU+) up to 19.75%.
Global First Power also wants a shift from no need to refuel in a 20-year operating life to provision for on-site refueling and defueling with periods varying from three to 13.5 years. They also want to double their facility design life from 20 years to 40 years.
Despite all these significant changes to key elements of the design, the CNSC staff concluded that the Global First Power MMR project remained within scope of its initial (very different) description.
Another example of SMR project creep is in New Brunswick. In June 2023, the provincial utility NB Power applied to the CNSC for a licence to clear a site for the ARC-100 design at the Point Lepreau nuclear site on the Bay of Fundy. The design for the sodium-cooled reactor requires HALEU fuel, which is scarce because of sanctions imposed on Russia, the sole supplier.
News reports have suggested the ARC-100 design might need to change because changing the fuel means changing the design. Meanwhile the ARC company CEO left suddenly, and staff received layoff notices. Despite these obvious problems, the application under CNSC review and a provincial environmental assessment underway with the CNSC are continuing with the original design.
SMRs complicate radioactive waste management
One of the (many) false promises floated about SMRs is that they will alleviate the significant challenges of managing radioactive wastes. This is patently false. Some of this misleading rhetoric stems from the notion of “recycling” and claims by some SMR promoters that their particular design of reactor will use high-level radioactive wastes as “fuel” for their reactor.
But the reality is that the introduction of so-called “next generation” designs of reactors in Canada will only complicate the already complex set of problems related to the caretaking of these extremely hazardous materials.
Canada’s current fleet of CANDU power reactors all use natural uranium. The rather long list of small modular reactors under consideration or being promoted in Canada would all use enriched uranium.
Enrichment ranges from 3.4% to 4.95% for GE Hitachi’s BWRX-300 reactor design selected for construction at the Darlington site, to 19.75% for Global First Power’s MMR currently under review for the Chalk River site on the Ottawa River.
To date, the only reactors in Canada that have used enriched fuel are research reactors at universities and nuclear laboratory sites. Their enriched fuel has been imported from the United States with the subsequent wastes repatriated to the U.S. under the Global Nuclear Energy Partnership.
The shift from natural uranium to enriched uranium in commercial power reactors in Canada will fundamentally change the nature and characteristics of the spent fuel waste and will take away one of the nuclear industry’s favourite pitch points for the CANDU design: that there is no potential for criticality after the fuel is removed from the reactor.
The new potential for the irradiated enriched fuel wastes to “go critical” is only one of the many problems being overlooked by both government and industry.
Another very obvious shift is in the dimensions of the fuel, from the relatively uniform dimensions of CANDU fuel to the widely divergent shapes and sizes of fuel being depicted for the various small modular reactor designs.
The CANDU fuel bundles are approximately 50 cm long and 10 cm in diameter. In contrast, the fuel waste dimensions are significantly different for SMRs. For example, the BWRX-300 fuel bundles are much larger, the casks much heavier, and the reactor will generate higher level activity wastes. These differences will require different approaches and designs for interim and long-term dry storage of used fuel.
SMR wastes not considered in Canada’s repository design
As a fleet, small modular reactors will generate more waste per energy unit than the larger conventional reactors that preceded them. But in Canada they will also require redesign of the “concept” plan currently being promoted for the long-term dispositioning of the used fuel to a deep geological repository (DGR).
Since 2002 an association of the nuclear power companies, operating as the Nuclear Waste Management Organization (NWMO), have been pursuing a single site to bury and then abandon all of Canada’s high-level nuclear waste.
Their siting process, launched in 2010, caught the interest of 22 municipalities that allowed themselves to be studied for the “$16-24 billion national infrastructure project.” Hundreds of millions of dollars later – with tens of millions going directly into the coffers of the participating municipalities – the NWMO is now down to two candidate sites in Ontario.
The NWMO say they will make their final selection by the end of 2024. But even at this late date they have produced only “conceptual” descriptions of their repository project, including for key components such as the packaging plant where the fuel waste would be transferred into that final container, and the DGR itself. But all of the conceptual work is premised on the characteristics and dimensions of the CANDU fuel bundle.
The process lines of the used fuel packaging plant, the final container, and the spacing requirements for the repository will all need to be redone for different SMR wastes with their very different dimensions and characteristics.
While it could be said that the NWMO design progress has been surprisingly slow given their target of selecting a site this year and beginning the regulatory and licensing process next year, it will be back to square one if their proposed DGR is to accommodate SMR wastes.
There is, however, a strong possibility that the regulator, the CNSC, will allow the NWMO to skate through at least the first license phase with large information gaps, as the CNSC is doing with the plan to construct four BWRX-300s at the Darlington site.
As mentioned in the example of “project creep,” earlier this year the CNSC announced it would accept an environmental assessment approval of a generic 2009 reactor proposal instead of requiring that the BWRX-300 be subject to an impact assessment. This was despite the marked differences between the technologies assessed in 2009 and the BWRX-300 technology.
These differences will impact the management of the project’s radioactive waste. For example, the BWRX-300 public dose rates are estimated to be 10 x higher for one accident scenario (pool fire) and 54% higher in a dry storage container accident, the waste contains different proportions of radionuclides than the waste that was assessed in 2009, radio-iodine and carbon-14 emissions will be higher, alpha and beta-gamma activity per cubic metre of waste will be higher and the BWRX-300 will generate higher activity spent fuel.
Despite the NWMO having successfully wooed two small municipalities, there is broad opposition to the transportation, burial and abandonment of all of Canada’s high-level radioactive wastes in a single location, either in the headwaters of two major watersheds in northern Ontario or the rich farm lands of southwestern Ontario.
This opposition is amplified by concerns about SMR wastes and the NWMO’s open ticket to add other operations to their DGR site. Of particular concern are the potential for the NWMO to add an SMR to power their repository site or even to add a reprocessing plant at the site to extract plutonium from the used fuel. The Canadian government’s refusal to include an explicit ban on commercial reprocessing in the 2022 review of the national radioactive waste policy heightened the latter concern.
Who/what is behind the SMR push in Canada?
Although proponents claim that SMRs will contribute to climate action, critics are sceptical. It is doubtful that any SMR will be built in time to contribute to Canada’s target to decarbonize the electricity grid by 2035, and independent research found that SMRs will cost substantially more than alternative sources of grid energy.
The high cost and lengthy development timelines of SMRs, the questionable claims of climate action, as well as the significant challenges related to SMR wastes, raises an obvious question: who is pushing SMRs and why?
A central reason is a political imperative to keep the Canadian nuclear industry alive. The industry is small in Canada, but nuclear power looms large in the political imagination. Canada sees itself as a global leader in the peaceful use of nuclear energy.
Without a nuclear weapons industry, Canada needs nuclear exports to keep its domestic industry alive and ensure Canada’s membership in the international nuclear club. Earlier this year, Canada released an action plan to get nuclear projects built faster and ensure that “’nuclear energy remains a strategic asset to Canada now and into the future.”
Since the start of the nuclear age, Canada has spent a disproportionate amount of research funding on nuclear reactor development. Politicians see the CANDU design as a success, despite its costly legacy and lackluster exports. The CANDU reactors in Canada have all required significant public subsidies, and the CANDUs sold for export have been heavily subsidized by Canada as well.
Selling more CANDUs outside Canada is unlikely in the foreseeable future. But Canada wants a nuclear industry, and that requires choosing and aggressively marketing at least one nuclear reactor design. Despite being a U.S. design, the G.E. Hitachi BWRX-300 is the chosen favourite in Canada. The reactor, in early development at the Darlington site, is being promoted globally by Ontario Power Generation as part of an international collaboration with GE Hitachi Nuclear Energy, the Tennessee Valley Authority, and Synthos Green Energy.
What’s the future for SMRs in Canada?
Since the nuclear industry and its government partner Natural Resources Canada (NRCan) launched their SMR roadmap in 2018, the political and business hype for SMRs has been intense. The SMR buzz is meant to attract private sector investment, but so far that strategy is failing.
Almost everyone understands now that SMRs, like the CANDUs, are expensive projects that will need continuous massive public subsidies. To date, taxpayers have provided just over $1.2 billion in direct subsidies to SMR proponents in Canada, not nearly as much as the industry will need to develop an SMR fleet in the country.
A broad coalition of groups – from climate activists to Indigenous organizations and other groups protecting lands and waters from radioactive waste – have been pushing back against public funding for SMRs. A 2020 statement signed by 130 groups called SMRs “dirty, dangerous distractions” from real climate action. In March this year, 130 groups in Canada also signed the international declaration against new nuclear energy development launched in Brussels at the Nuclear Summit organized by the International Atomic Energy Agency.
While civil society opposition to SMRs is broad and substantial in Canada, ultimately the exorbitant cost of SMRs will be their undoing. Conclusive analysis shows that SMRs cannot compete economically with wind, solar and storage systems.
SMRs will last as long as governments are willing to pour public funds into them, and SMRs will start to disappear after the money tap is turned off. Already the nuclear hype in Canada is turning back to big reactors.
The Bruce Nuclear Generating Station on Lake Huron in Ontario, with eight CANDU reactors, is already the largest operating nuclear plant in the world. Bruce Power recently began the formal process to develop four new big reactors at the site, to generate another 4,800 megawatts of electricity. It remains to be seen if the sticker shock for the proposed big nuclear reactors will, like it has for SMRs, scare off investors.
Although more than six years of SMR promotion in Canada has produced almost no private investor interest, the SMR buzz remains strong. The SMR star may be fading but the SMR story is far from over.
Brennain Lloyd is the coordinator of Northwatch in Ontario. Susan O’Donnell is the lead researcher for the CEDAR project at St. Thomas University in New Brunswick.
