Seismic responses of a fuel assembly in nuclear heating reactor

The fuel assembly (FA) stands as a pivotal component within nuclear reactors, impacting safety, reliability, and economic viability of the entire facility. In the 200 MW nuclear heating reactor (NHR200-II), the FA embodies a novel structural configuration, characterized by a 9 × 9 fuel bundle arrangement enclosed within a singular channel. During seismic events, challenges like potential FA damage and control rod insertion failures can pose safety risks. Therefore, a comprehensive structural integrity assessment is essential. The seismic responses of the NHR200-II FA unidirectionally and bidirectionally under different boundary conditions, using a time-compressed El-Centro N-S earthquake (1.5 times amplification, ∼0.36 g peak acceleration), are analyzed in detail. We examine stress distribution, channel-spacer grid interactions, dynamic clamping, acceleration responses, and response spectra. Results confirm the robust seismic performance of NHR200-II FA, with potential for future seismic fluid–structure interaction analysis based on the model used in this work.