The Influence of the Ion Implantation on the Degradation Level of the Coated Particles of Nuclear Fuel Samples

TRIstructural ISOtropic (TRISO)-particle fuel is nuclear fuel used in high-temperature reactors. During reactor operation, partial damage may occur to the covering layers of this fuel. The authors of the publication propose an ion implantation method as a surrogate for neutron irradiation in the reactor core. This method makes it possible to reflect the damage that can be caused by irradiating samples in the reactor much faster and without having to deal with radioactive material. This paper presents an experiment on the p-TRISO samples, with a focus on the level of damage to the covering layers that could occur after 1, 3 and 5 years of neutron irradiation. The paper presents research conducted on both polished and unpolished p-TRISO fuel samples implanted with ions (Ne+, He+) of appropriate fluence and energy. It is necessary to determine whether the passage of time affects the occurrence of structural changes in p-TRISO fuel layers and, at the same time, whether it contributes to an increase in the probability of damage in the examined fuel material. The result of this work is confirmation that ion implantation is an efficient tool for reflecting irradiation-induced damage in the p-TRISO samples. In addition, the assumption that the sample does not need to be polished to obtain information about damage in the p-TRISO covering layers was confirmed.