Additive manufacturing technology

with its advantages in fabricating complex structures and enhancing component performance

presents significant application prospects in the development of nuclear fuel components. However

China's current nuclear regulatory framework lacks specific technical requirements for additive manufacturing processes

and corresponding nuclear safety supervision practices are yet to be established

which hinders the engineering application of this technology in the nuclear field. This paper systematically investigates the safety evaluation system and in-reactor regulatory pathway for additively manufactured components established by the U.S. Nuclear Regulatory Commission (NRC)

with particular emphasis on analyzing the material performance evaluation methodology and licensing process for Westinghouse's additively manufactured thimble plugging devices. Based on this analysis and considering China's nuclear safety regulatory framework

this study proposes an evaluation system and regulatory implementation pathway for in-reactor application of additively manufactured nuclear fuel components

encompassing out-of-pile and in-pile material performance verification as well as component functional qualification. The results can provide technical support and regulatory references for promoting the application of additive manufacturing technology in domestic nuclear fuel development and commercial reactor irradiation testing.