NuScale Completes First Batch of Boron Carbide Pellet Manufacturing for SMR Emergency Cooling System

en.Wedoany.com Reported - On September 1, NuScale Power and advanced nuclear materials manufacturer MillenniTEK completed the manufacturing of the first batch of boron carbide pellets for the passive emergency core cooling system (ECCS) of small modular reactors. NuScale defines this as a first-of-a-kind fabrication of such nuclear safety components, with the work involving both dedicated components and supporting manufacturing processes, targeting its SMR design that has been approved by the U.S. Nuclear Regulatory Commission.

This batch of boron carbide pellets corresponds to the ECCS supplemental boron system in the NuScale US460 design. According to the U.S. Nuclear Regulatory Commission's final safety evaluation report, the system is configured with two supplemental boron dissolution devices located on the inner wall of the containment vessel, with solid boron carbide pre-loaded as part of the system; upon ECCS activation, the devices deliver a boron-containing solution into the recirculating coolant. The system is incorporated into the core subcriticality control design under certain design-basis event conditions.

Prior to this first-of-a-kind fabrication, NuScale had already completed boron carbide dissolution testing for the ECCS supplemental boron system. NRC safety evaluation documentation indicates that the testing program was designed to measure the fundamental dissolution characteristics of boron carbide, with the test results subsequently used to determine conservative dissolution rate parameters adopted in the boron transport analysis. The resulting test data have been incorporated into the safety analysis framework underpinning the US460 standard design approval.

This pellet manufacturing was undertaken by MillenniTEK. The company's technical ceramics business primarily processes powdered raw materials into high-tolerance solid components, and it also operates a high-temperature materials prototype component business for SMRs, microreactors, and space reactors. NuScale stated that this manufacturing effort with MillenniTEK is advancing the transition of the relevant components from the design and testing phase to production-ready processes, in preparation for manufacturing for the first batch of initial customer projects.

The US460 standard design corresponding to the boron carbide pellets received standard design approval from the U.S. Nuclear Regulatory Commission on May 29, 2025. The US460 features six NuScale Power Modules, each with an electrical output of 77 megawatts, for a total electrical output of 462 megawatts for the entire design. The NRC approval completed the technical review of the US460 standard design, and the approved design can be referenced in subsequent applications for construction permits, operating licenses, combined licenses, and manufacturing licenses.

When NuScale previously submitted the US460 standard design application, it had already included the emergency core cooling system, the supplemental boron system, and related verification tests within the scope of the design review. Following the completion of the first batch of boron carbide pellet manufacturing with MillenniTEK, the component has now formed a continuous engineering milestone chain of "design review—dissolution characteristic testing—first-of-a-kind fabrication." NuScale is currently continuing to advance the dedicated component manufacturing processes and supply chain readiness.