Assessment of the lifecycle cost of nuclear-grade coolants for advanced reactors

The vast majority of advanced nuclear energy systems (both fission and fusion) use coolant fluids other than water. While the thermophysical properties of all these coolants are well known, their cost, when the appropriate nuclear-grade characteristics are accounted for, is not. The fluids analyzed in this research are: light water (taken as reference), liquid sodium, liquid lead and lead-bismuth eutectic (LBE), organic coolants (terphenyl derivatives), liquid salt (FLiBe) and helium gas. A credible estimate of all the costs associated with such coolants must include raw material supply, transportation, initial purification to nuclear-grade specifications, chemistry control during operation and disposal. Here we analyze the current purchase cost of various types of reactor coolants considering the target purity required for the start of the nuclear operations in a nuclear power plant, including the cost of pre-treatment if necessary. We also perform an analysis of the costs required to control the coolant chemistry and purity throughout the reactor lifetime. To that end, all major expected impurities and the corresponding concentration limits have been identified for each coolant. Consequently, the state-of-the-art purification methods and related systems have been analyzed and their investment and operating costs have been estimated. The cost of coolant makeup has also been considered in the analysis where appropriate. The cost of disposal of the coolants at the backend of the reactor service life has been excluded due to its negligible discounted value. The final results of the research include the estimate of a CAPEX cost expressed in $/kg of coolant and an OPEX cost in $/year per megawatt. • Performed lifecycle cost analysis of seven nuclear-grade coolants for advanced reactors. • Reported nuclear-grade purity and typical impurities for each coolant. • Techno-economic assessment revealed significant cost variations among coolants, including CAPEX and OPEX. • FLiBe and helium identified as the priciest coolants; Organic coolant costs vary based on purification approaches. • Provided a foundation for accurate cost estimates in advanced reactor designs.