Fueling Change: Canada and USA’s Joint Report Energizes TRISO Nuclear Fuel Regulation

On June 29, 2023, the Canadian Nuclear Safety Commission (the “CNSC”) and the United States Nuclear Regulatory Commission (the “US NRC” and, together with the CNSC, the “Regulators”) released their joint Report titled “Final Report concerning Tristructural Isotropic (TRISO) Fuel Qualification”[1] (the “Report”).[2] The Report establishes a common regulatory position between the Regulators on the qualification of tristructural isotropic (TRISO) fuels and identifies gaps in the understanding of the technology. This Report is a significant step forward for use of TRISO fuels in North America.

TRISO fuels are not a novel concept;[3] however, interest in the technology has increased with the advancement of nuclear reactors and the desire for safer alternatives to traditional fuels. TRISO fuels are a formidable fuel alternative since they can withstand pressures and temperatures of up to 500 bar and 1600°C, respectively, and can resist neutron irradiation, corrosion and oxidation.[4] These characteristics provide protections from conditions consistent with nuclear meltdowns and are a result of the fuel’s structural design.

TRISO fuel consists of a nuclear material encased by three layers of “isotropic materials” – usually in a spherical or cylindrical geometry. Though each particular design can vary, TRISO fuels are typically coated in three different layers: (1) carbon, which absorbs the nuclear reaction products; (2) pyrolytic carbon, which provides the fuel’s ability to withstand high temperatures and pressure; and (3) silicon carbide, which contains metallic fission products and provides additional strength.[5] The bulk of the Report’s discussion centers on the literature concerning the structure of TRISO fuel, its promised qualities and its ability to withstand the conditions of nuclear reactors.

Image Source: Created by Andrew J. Dusevic.

Figure 1: Diagram of a typical TRISO fuel pellet

The Report outlines the Regulator’s common position on the regulation and assessment of TRISO fuels. In particular, the Report acknowledges the broad range of operating conditions at which TRISO fuels may be used and identifies areas of concern, regulatory gaps, important qualification metrics and areas requiring further investigation. Though the Report confirms various broad generalities applicable to TRISO fuels, it emphasizes the need to regulate each proposed use on a case-by-case basis[6] subject to existing regulatory practices in place.

Canada’s nuclear regulations are designed to be broad; however, they have been, for the most part, only applied commercially to Canada Deuterium Uranium (CANDU) reactors – a Canadian-designed heavy water reactor. The application of these regulations to TRISO fuels will pose new challenges where cooperation with industry will play a vital role. Notably, the Report speaks to ongoing engagements by the Regulators with Kairos Power, Ultra-Safe Nuclear Corporation (“Ultra-Safe”) and X-Energy who have all proposed the use of TRISO fuels in their reactor designs.   

Ultra-Safe has been working with Canadian Nuclear Laboratories (CNL) to develop TRISO fuels[7] and has an active microreactor deployment project in Chalk River, Ontario.[8] Likewise, X-Energy has been particularly active in Saskatchewan, agreeing to collaborate with Cameco[9], the First Nation Power Authority[10] and the Saskatchewan Industrial & Mining Suppliers Association Inc.,[11] among others, to explore opportunities and build capacity for advanced small modular reactors.

The Report marks a pivotal moment in nuclear fuel technology and offers a promising pathway towards a safer and more resilient approach to nuclear energy production. Though the Report highlights critical areas for ongoing research and regulatory adaptation for the safe and risk-informed use of TRISO fuels, it has also opened up a new avenue for proponents hoping to deploy their rector designs in Canada.

A business that is considering a resource project should consult legal counsel. McKercher LLP has lawyers with considerable experience assisting businesses with regulatory compliance, financing, resource projects, and implementation of new technologies. If you have any questions or comments about the above, please do not hesitate to contact a lawyer from our Natural Resource Practice Group.

About the Authors:

Andrew Dusevic is an associate in McKercher LLP’s Saskatoon office practicing in the areas of Indigenous, corporate governance, regulation, natural resources and energy law.

Annie Quangtakoune is an associate in McKercher LLP’s Regina office advising emerging and high-growth companies in the areas of corporate governance, regulation, venture financing, equity management and employment issues. 

Partner Contact:

Chris Masich is a Partner practicing in the Firm’s Saskatoon office and the Chair of the Natural Resource Practice Group. Chris maintains a commercial transactions practice focusing on acquisitions, divestitures, business transactions, and project development for Saskatchewan key economic sectors – energy, natural resources and agricultural. Chris often collaborates and integrates with international and national law firms providing local Saskatchewan counsel advice to global companies with Saskatchewan projects. 

About McKercher LLP:

McKercher LLP is one of Saskatchewan’s largest, most established law firms, with offices in Saskatoon and Regina. Our deep roots and client-first philosophy have helped our firm to rank in the top 5 in Saskatchewan by Canadian Lawyer magazine (2023/24). Integrity, experience, and capacity provide innovative solutions for our clients’ diverse legal issues and complex business transactions.

This post is for information purposes only and should not be taken as legal opinions on any specific facts or circumstances. Counsel should be consulted concerning your own situation and any specific legal questions you may have.


[1] The Report was prepared pursuant to the “Memorandum of Cooperation on Advanced Reactor and Small Modular Reactor Technologies between the Canadian Nuclear Safety Commission and the United States Nuclear Regulator Commission” executed August 15, 2019, which is aimed at enhancing cooperation in areas that include reactor design, research, staff training, and the comparison of regulatory practices.

[2] United States Nuclear Regulatory Commission and Canadian Nuclear Safety Commission, “Final Report concerning Tristructural Isotropic (TRISO) Fuel Qualification” [Report], (June 2023) at 6, online (pdf): < nrc.gov>[https://web.archive.org/web/20231113204516/https://www.nrc.gov/docs/ml2317/ml23172A242.pdf]. In particular the Report aims to: (1) Provide the evidentiary basis to support regulatory findings; (2) Identify areas of TRISO fuel qualification that are design dependent; and (3) Highlight areas where additional information, testing, or both are needed to support regulatory approval.

[3] Sonal Patel, The Allure of TRISO Nuclear Fuel Explained, (1 March 2021), online: Power Magazine <powermag.com> [https://www.powermag.com/the-allure-of-triso-nuclear-fuel-explained/].

[4] Portal et al “Coated particle fuel to improve safety, design, economics in water-cooled and gas-cooled reactors” 38: 3-4 Progress in Nuclear Energy 407 at 408.

[5] J Portal et al “Coated particle fuel to improve safety, design, economics in water-cooled and gas-cooled reactors” 38: 3-4 Progress in Nuclear Energy 407 at 408 [J Portal].

[6] Report, supra 1 at 28.

[7] Canadian Nuclear Laboratories, “CNL successfully fabricates advanced Small Modular Reactor fuels”, (13 April 2021), online (blog): <cnl.ca> [http://web.archive.org/web/20231113195004/https://www.cnl.ca/cnl-successfully-fabricates-advanced-small-modular-reactor-fuel/].

[8] Ultra Safe Nuclear Corporation, “McMaster University, Ultra Safe Nuclear Corporation, and Global First Power Sign MOU to Study Deployment of Micro Modular Reactor (MMR®)”, (11 December 2022), online (blog): <usnc.com>[https://web.archive.org/web/20230811130025/https://www.usnc.com/mcmaster-university-ultra-safe-nuclear-corporation-and-global-first-power-sign-mou-to-study-deployment-of-micro-modular-reactor-mmr/].Canadian Nuclear Laboratories, “AECL, CNL and Global First Power unveil the site of GFP’s proposed small modular reactor at the Chalk River Laboratories” (12 May 2023), online:<cnl.ca>[https://www.cnl.ca/aecl-cnl-and-global-first-power-unveil-the-site-of-gfps-proposed-small-modular-reactor-at-the-chalk-river-laboratories/].

[9] X-energy, “X-energy and Cameco to Explore Collaboration to Support Xe-100 Small Modular Reactors”, (16 September 2021), online (blog): <x-energy.com>[https://web.archive.org/web/20231113202642/https://x-energy.com/media/news-releases/x-energy-and-cameco-to-explore-collaboration-to-support-xe-100-small-modular-reactors].

[10] X-energy, “X-energy Canada and First Nations Power Authority Collaborate to Build Indigenous Capacity for Future Advanced Small Modular Reactor Industry”, (15 December 2021), online (blog):<x-energy.com> [https://web.archive.org/web/20231113202836/https://x-energy.com/media/news-releases/x-energy-canada-and-first-nations-power-authority-collaborate-to-build-indigenous-capacity-for-future-advanced-small-modular-reactor-industry].

[11] X-energy, “X-energy Canada and SIMSA Collaborate to Support the Potential Deployment of Xe-100 Small Modular Reactors” (26 July 2022), online (blog): <x-energy.com>[https://web.archive.org/web/20231113203202/https://x-energy.com/media/news-releases/x-energy-canada-and-simsa-collaborate-to-support-the-potential-deployment-of-xe-100-small-modular-reactors].