Conceptual design of a long cycle small modular reactor core with annular UO2 and FCM (TRU) fuels

Abstract

In this work, new small modular reactor (SMR) core using annular UO2 and FCM (TRU [Transuranics]) fuels is conceptually suggested for TRU consumption and effective power generation, and neutronic and thermal hydraulics analyses are performed to show its feasibility and performances. In this core concept, the annular fuels previously suggested are combined with TRU containing FCM annular fuels to improve economics and safety of SMR, and to reduce high radiotoxicity TRU nuclides by combing superior cooling performance of annular fuel, and high thermal conductivity and superior irradiation performances of FCM fuel. In addition, FeCrAl cladding is employed as the accident tolerant cladding to reduce the oxidation and hydrogen generation under transients. The basic objective of this work is to show if a long cycle SMR core with increased power rating and considerable TRU consumption rate can be designed with these advanced fuels and accident tolerant FeCrAl cladding. From the analysis, it was shown that the SMR core with 15% power increase can be designed to have 22 months cycle length and a similar to 16% net TRU consumption rate over all the discharged fuel assemblies.