Neutronic Design of a PWR-based SMR (Small Modular Reactor) Core using GdN Coating Burnable Absorber for Soluble Boron-Free Operation

초록

In this work, a PWR-based SMR core for soluble boron-free operation is designed using gadolinium nitride coating burnable absorber (GdN-CBA), and its performances are analyzed in detail. In particular, the Westinghouse type 17x17 fuel assemblies are considered but the lattice pitch is adjusted to have better neutronic economy and to make the moderator temperature coefficient more favorable for soluble-free operation. Additionally, the load-following operations considering normal and emergency load change scenarios for the design core are analyzed in detail with control rod insertion strategies. The results of the analysis showed that GdN-CBA effectively adjusted the excess reactivity of the core, thereby the core can be operated over 1500 EFPDs (~29.6 MWd/kg burnup) and the load-following operations are possible without violation on the limits of power distributions. © 2024 AMERICAN NUCLEAR SOCIETY. All rights reserved.