NANO Nuclear Energy Inc. (NASDAQ: NNE) (“NANO Nuclear” or “the Company”), a leading advanced nuclear energy and technology company focused on developing clean energy solutions, today announced that it has assembled the first reactor core hardware of its ZEUS microreactor for initial non-nuclear testing.

ZEUS, a solid core battery reactor, is being developed by NANO Nuclear as part of the next generation of portable, on-demand capable, advanced nuclear microreactors to provide clean, scalable power for data centers, remote locations, industrial sites, military operations, and disaster relief scenarios. The successful validation of the reactor core through scaled testing will position NANO Nuclear to advance toward full prototype construction and licensing efforts in the coming years.

The assembled hardware consists of a 1:2 scale block, precisely engineered to be representative of a fuel element of the ZEUS microreactor core. This milestone represents a major advancement in NANO Nuclear’s continued development of its proprietary microreactor technology.

The initial testing phase will focus on the assessment of the thermo-mechanical performance of the block under anticipated prototypical conditions for ZEUS. The results will inform the next stages of reactor development. These results will be crucial for verifying engineering plans, refining physics models, and optimizing ZEUS core and heat management systems.

Figure 1 – NANO Nuclear Energy Inc.’s fuel element being set up for testing.

“We are very excited to have completed the first ZEUS reactor core block for non-nuclear testing,” said Prof. Peter Hosemann, Head of Nuclear Reactor Design and Materials of NANO Nuclear. “This very precise component will be heated conventionally using linear heaters as fuel rod surrogates. The test will be used to verify temperature distribution, to investigate fit tolerances, and to confirm and benchmark our models, paving the way for a larger sub-core assembly.”

“I am thrilled to see our transition from design to hardware assembling and testing for a key component of our ZEUS reactor,” said Prof. Massimiliano Fratoni, Senior Director and Head of Reactor Design of NANO Nuclear. “The lack of an in-core fluid in our ZEUS design not only simplifies greatly the design but also enables rapid prototyping and non-nuclear testing. We are expecting to iterate quickly through progressively larger scale tests up to full core.”

Figure 2 – Single core block fully outfitted with linear heaters as fuel rod surrogates (left image) Infrared camera image of the block during initial test (right image).

NANO Nuclear’s engineering team is preparing to mount insulation, fixtures, and instrumentation to create a single-block demonstration unit, which will eventually scale up to a fully functional demo core assembly. In the next phase, the team will integrate cabling, sensors, and additional structural components to build a fully instrumented demo unit. This will enable the team to gather essential data on heat transfer, material performance, and overall reactor safety margins, facilitating real-world validation of the ZEUS reactor’s thermal and structural performance and ensuring that the design meets expectations before full-scale assembly.

“Achieving this hardware milestone represents a major step forward in our ZEUS microreactor program,” said James Walker, Chief Executive Officer of NANO Nuclear. “This testing will provide our team with the key thermal and mechanical insights needed to fine-tune the core design before full-scale fabrication and regulatory engagement.”