Research Progress on Modular Construction Technology and Seismic Performance Evaluation for Generation III Nuclear Power Plant-Paper

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The study evaluates the seismic performance of pile-rafted small modular reactor (SMR) structures on non-rock, sandy sites, where soil–pile–structure interaction can affect nuclear safety. It also reviews the use of steel-concrete-steel (SCS) construction in Generation III nuclear power plants; the cited analysis indicates that at a 0.3g safe shutdown earthquake level, steel plates remain elastic and concrete cracking does not cause structural failure.<br /><br />Researchers conducted large-scale shaking-table tests using a sand-site model, a 20-pile group and a nuclear-island building model. They applied recorded and synthetic earthquake motions in three directions and measured responses in the soil, building and internal components.<br /><br />Pile-raft effects substantially reduced acceleration amplification in soil near the piles compared with far-field soil. Under the Chi-Chi motion, near-field amplification factors were about 41–51% of far-field values, depending on direction. The building’s response varied by component: horizontal acceleration amplification was greatest in the external plant and nuclear equipment, while the steel containment vessel showed weaker amplification, attributed partly to its top weight.<br /><br />Response-spectrum analysis indicated that the pile-raft foundation and superstructure filter high-frequency components of seismic motion, reducing acceleration sensitivity. The findings support the use of pile-raft foundations to improve the seismic performance of SMRs on sandy, non-rock sites and provide evidence to inform their design and evaluation.

Keywords

seismic performance

pile-raft foundation

small modular reactor

SMR

soil-pile-structure interaction

shaking-table tests

sandy site

nuclear safety

steel-concrete-steel

response spectrum analysis