Rosatom, the Russian state-owned nuclear conglomerate, went on to announce the successful completion of critical tests on fuel that is designed for high-temperature gas-cooled reactor fuel – HTGR, confirming its stability even under extreme heat. These results are indeed a part of an experimental validation programme that was launched in 2021 so as to establish operating limits of Russian-manufactured fuel.
Before being exposed to the extreme conditions, the fuel compacts – composed of spherical microelements that are embedded in graphite cylinders got first irradiated within the research reactors as per the standard conditions at temperatures that range from 1,000°C to 1,200°C. These samples then got tested for over 500 hours at a temperature of 1,600°C.
Rosatom also went on to state that some fuel samples, having a burnup rate of 8% in heavy atoms – h.a. went through irradiation at 1,700°C for more than 380 hours. These outcomes look forward to confirming fuel behavior under pretty intense thermal as well as irradiation stress, which is crucial for future development when it comes to HTGR technologies.
The project supervisor at Rosenergoatom, Fyodor Grigoryev, said that over 20 high-temperature gas-cooled reactor fuel samples were evaluated in post-irradiation studies in 2025. The collected data went on to confirm the operational thresholds set out within the design specifications, with burnup levels that ranged between 3% and 13%.
As per the group, these tests were built upon the research that was carried out in the past four years under the integrated programme for computational as well as experimental validation of HTGR fuel. The overall process is aimed at making sure of a completely domestic production chain, sans depending on the imported technologies or even, for that matter, the raw materials.
In 2026, Rosatom looks to initiate the reactor tests on prototype fuel manufactured on a national pilot production line that is developed by JSC Research Institute Scientific as well as Production Association LUCH. This next phase looks forward to laying the technological groundwork in terms of HTGR power plant construction within Russia.
These reactors are anticipated to play a role when it comes to future hydrogen as well as hydrogen-based product value chains. Their fuel, of the TRISO – TRI-structural ISOtropic type, is made up of uranium oxycarbide particles that are enriched up to 17% U-235, encapsulated within the many layers of carbon along with silicon carbide. This structure makes sure of containment of fission products at temperatures of almost 1,600°C.