**4. Summary**

In this study, the details of retention and desorption of implanted deuterium were investigated and the responsible traps in irradiated Zircaloy-2 were identified. The thermal desorption of deuterium was conducted on Ni3+ ion-irradiated samples and cold-worked samples. The following conclusions have been drawn:


**Author Contributions:** Conceptualization, H.W.; TDS, Y.S. and K.T.; TEM, K.Y.; project administration, H.W.; funding acquisition, H.W., All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Acknowledgments:** This work was supported by the Collaborative Research Program of Research Institute for Applied Mechanics, Kyushu University.

**Conflicts of Interest:** The authors declare no conflict of interest.
