US-based nuclear waste storage and disposal company Deep Isolation has completed Project PUCK, a US government-funded initiative to demonstrate the feasibility and potential commercial readiness of its Universal Canister System (UCS) to manage TRISO TRI-structural ISOtropic) used nuclear fuel. Deep Isolation worked with Kairos Power to conceptually evaluate the use of TRISO pebble fuel, verifying UCS as a safe, scalable solution for deep borehole disposal for next-generation reactors.
Project PUCK (Performance Validation of the Universal Canister System for Kairos Power) was launched in July 2024 under a Small Business Innovation Research (SBIR) grant from the Department of Energy (DOE). It has validated the potential use of the UCS to safely and cost-effectively manage TRISO used fuel from Kairos Power’s planned fluoride salt-cooled high-temperature reactor (KP‑FHR). UCS, optimised for deep borehole disposal, is a triple-purpose canister designed to enable the safe storage, transport, and permanent disposal of used nuclear fuel and high-level radioactive waste. Deep Isolation says its design also allows compatibility with mined repositories, offering multiple disposal pathway options.
The project addressed the challenges of long-term management of accumulating used fuel inventories. Results confirmed that TRISO used fuel is compatible with the UCS and suitable for disposal in both conventional mined repositories and deep boreholes, which offer enhanced safety and a smaller surface footprint. A detailed economic analysis of the cost benefits of the UCS and borehole disposal approach identified potential process and design enhancements to enable broader commercial adoption across the advanced reactor sector.
“What we’ve accomplished with Kairos Power is more than a technical milestone – it’s a strategic leap toward long-term sustainability in nuclear energy,” said Jesse Sloane, Executive Vice President of Deep Isolation. “The UCS, paired with deep borehole disposal, offers an adaptable and forward‑thinking end-to-end solution that can serve the advanced reactor industry for the future.”
According to Deep Isolation, the findings provide a data-driven framework for stakeholders evaluating back-end fuel cycle management solutions. “Analyses confirm that Deep Isolation’s UCS, combined with deep borehole disposal, offers a viable, cost-competitive, and scalable solution for nuclear waste management. The analyses demonstrate that the UCS is both technically and commercially ready for TRISO fuel, positioning it as a strong option for future deployment by advanced reactor developers and the DOE.”
Per Peterson, Chief Nuclear Officer of Kairos Power, said the company looks forward to continued collaboration. “Together, Deep Isolation and Kairos Power are setting a precedent for innovation, safety, and sustainability in the safe and effective management of spent fuel from high temperature reactors.”
