Advances in the Conceptual Design of a Small Modular Reactor of the Integrated Pressure Water Type

Abstract

The development and deployment of small nuclear reactors (SMRs) as part of the new generations of nuclear reactors has gained significant importance in recent years. The advantages of SMRs is due not only to their ability to generate low-emission energy, but essentially to their modularity characteristics and their small dimensions. The TRI-structural-ISOtropic (TRISO) fuel, with proven advantages in graphite-gas type nuclear reactors, has been researched for use in PWRs. To obtain high proliferation resistance, extended fuel cycles for SMRs have been proposed. To obtain conceptual designs of SMR cores with a large cycle length, using low fuel enrichment, without shuffle, and with a relatively small core size is a challenge. In this work, a study was carried out to consider improvements in the behavior of the fuel cycles of a conceptual design of a SMR type iPWR, using TRISO fuel. These improvements are related to increasing reactor core power while maintaining extended fuel cycles and, on the other hand, considering different core zones with different fuel compositions, varying the packaging fraction, the last with the aim of to enlarge the fuel cycles and maintaining a flattened radial power distribution.