NuCube Energy and Canadian Nuclear Laboratories (CNL) have launched a joint research and development project to validate the heat pipe technology at the core of the NuSun microreactor. The agreement, announced on August 25, 2026, from Idaho Falls and Chalk River, tasks CNL with qualifying existing experimental data and calibrating the computational models used to predict heat pipe performance at temperatures exceeding 900 degrees Celsius.
The NuSun is a solid-state fission reactor cooled by heat pipes, eliminating the coolant pumps, complex heat exchangers, and large pressure vessels typical of conventional reactors. It uses TRISO fuel and is housed in a stainless steel casing, reducing the area required for emergency planning to the building’s own perimeter. The project encompasses data identification, modeling, and analysis to build a robust validation foundation — an essential prerequisite for the licensing pathway.
The qualified data provided by CNL will expand NuCube’s computational model validation database and are expected to play a central role in supporting the technology’s licensing process. CNL is Canada’s national nuclear laboratory: its involvement lends the project a significance that goes well beyond straightforward technical collaboration, as its certifications carry recognized weight with regulators. For NuCube, having CNL as a validation partner is a direct step toward commercialization.
The company was founded in 2023 at Idealab Studio by entrepreneur Bill Gross and nuclear engineer Dr. Cristian Rabiti. In February 2026, it had already raised $13 million in a funding round led by Arizona Nuclear Ventures, with participation from Rob and Jordan Rose Walton and Emission Reduction Corporation. The stated goal is to deliver high-temperature process heat — up to 1,100°C — for industrial sectors and data centers, markets where demand for clean, continuous energy has grown rapidly. NuCube also received a FY2026 GAIN voucher together with Argonne National Laboratory to verify its microreactor’s autonomous operation and remote monitoring capabilities through a digital twin.
The collaboration with CNL fits into a clear strategy: building the technical and regulatory credibility needed to bring the NuSun to market on a competitive timeline. Heat pipe microreactors do not require continuous on-site operators and are well suited to remote or off-grid environments. If validation proceeds as expected, NuCube will have a data set certified by a national laboratory — an element that is often decisive in approval processes. The industrial microreactor sector is still in its early stages of development: those who arrive with solid data and a clear licensing pathway hold a tangible competitive advantage.
