US-based X-energy Reactor Company X has completed milestones in the Canadian Nuclear Safety Commission’s (CNSC’s) pre-licensing Vendor Design Review (VDR) of its Xe-100 advanced small modular reactor (SMR). Following completion of a combined Phase 1 and 2 VDR process, CNSC concluded there are no fundamental barriers to licensing the Xe-100.

“The completion of the pre-licensing milestone underscores the regulatory and commercial readiness of the Xe-100 and demonstrates the opportunity to bring our advanced high-temperature gas reactor technology to the Canadian market,” said X-energy CEO J Clay Sell. “The work performed through the VDR and our engagements with the CNSC well position X-energy for future licensing applications.” The Xe-100 is a high-temperature gas-cooled reactor with a thermal output of 200 MWt or an electrical output of 80 MWe. It can be scaled into a four-pack 320 MWe power plant, fuelled by the company's proprietary TRISO-X tri-structural isotropic particle fuel.

X-energy has been engaged with CNSC in its optional VDR process since July 2020, and included the submission of more than 400 technical documents and white papers across 19 focus areas in the review. The process provides an opportunity for advanced nuclear technology developers to demonstrate understanding and compliance with Canadian licensing requirements and seek detailed feedback ahead of a formal license application. Feedback gathered during the process can be incorporated in future CNSC submissions and addressed in future VDR engagements. X-energy said it plans to pro-actively continue working with CNSC in pursuit of Phase 3 VDR in the future.

The CNSC said in its summary of the review it had concluded that X-energy "understands and has correctly interpreted the intent of regulatory requirements for the design of nuclear power plants in Canada". The review did identify some technical areas requiring further development "in order for X-energy to better demonstrate adherence to CNSC requirements", it said. Some of these will be addressed in a Phase 3 VDR, which enables a vendor to seek further information from the CNSC about Phase 2 issues. During Phase 3, a vendor may also ask the regulator to review activities taken with respect to the reactor's design readiness, following the completion of Phase 2.

The Xe-100 is one of two designs selected by to receive $80m each of initial cost-shared funding to build an advanced reactor demonstration plant that can be operational within seven years. The Xe-100 evolved from both the UK’s Dragon reactor at Winfrith in Dorset and the Pebble Bed Modular Reactor project in South Africa. X-energy was selected by the US Department of Energy (DOE) in 2020 to receive up to $1.2bn in matching funds under the Advanced Reactor Demonstration Program (ARDP) to develop, license, build, and demonstrate an operational advanced reactor and fuel fabrication facility by the end of the decade. X-Energy has since completed the reactor engineering and basic design and is developing a fuel fabrication facility in Oak Ridge in Tennessee.

ARDP is supporting X-energy’s initial deployment of the Xe-100 at Dow’s Seadrift, Texas facility as well as a new commercial facility to manufacture TRISO-X high-assay low-enriched uranium (HALEU) fuel for next-generation reactors. The project in Seadrift aims to be the first grid-scale advanced nuclear reactor deployed to serve an industrial site in North America. X-Energy in 2023 also signed a joint development agreement with utility Energy Northwest for the deployment of up to 12 Xe-100 SMRs.


Image: A look inside the Xe-100 reactor (courtesy of X-energy)