Core design and neutronic study on small reactor with advanced fuel designs

• Main Authors: Zhaozhan Zhang, Tianfan Wu, Yujing Wang, Shengli Chen, Cenxi Yuan, Jianyu Zhu
• Format: Article
• Language: English
• Published: Elsevier 2021-12-01
• Series: Nuclear Materials and Energy
• Subjects: Core design; Accident Tolerant Fuel (ATF); U3Si2-FeCrAl system; Small reactor; Annular fuel
• Online Access: http://www.sciencedirect.com/science/article/pii/S2352179121001356

After the Fukushima nuclear accident in Japan in 2011, the demand for new and innovative nuclear reactor technologies is increasing. The present work implements potential Accident Tolerant Fuels (ATF), U3Si2-FeCrAl, and innovative fuel designs, annular type, to small reactor systems. Neutronic analyses at both the assembly and core levels are performed for the traditional UO2-Zr system and the candidate ATF U3Si2-FeCrAl systems with cylindrical fuel rod as well as the annular fuel rod design. The whole core level studies show that with 10% enrichment fuel, the lifetime of the annular fuel can achieve up to 55 MWd/kg, whereas those of the cylindrical U3Si2-FeCrAl system and the UO2-Zr system are 60 and 67 MWd/kg, respectively. A larger thermal neutron penalty and higher 239Pu amount are observed in the ATF systems (more significant in the annular fuel design). Compared with the two cylindrical designs, the annular design leads to a higher power peak value and more heterogeneous power distribution in an assembly and in the core. The calculated negative fuel and moderator temperature coefficients throughout the whole life ensure the inherent safety of the core loaded with one of the three fuel assemblies. Therefore, the preliminary results indicate the rationality of the core design loaded with the traditional fuel and the U3Si2-FeCrAl system with both cylindrical and annular fuel designs.