The fluoride-salt-cooled high-temperature reactor (FHR) is a Generation IV nuclear energy system with huge potential for further development. Owing to its unique advantages, such as inherent safety, high economical potential, small modular design, environmental adaptability, and nonproliferation, FHRs have been the focus of considerable attention. In this study, the history and characteristics of FHR are reviewed first, including the concept initiation and active exploration stages. Then, the research status of FHR is introduced, which is about the state of the art in primary coolant systems, structural materials, key equipment, energy conversion systems, direct reactor auxiliary cooling systems, nuclear fuel, tritium control strategies, and experimental studies. Furthermore, the challenges faced by FHR technology are summarized, including corrosion of structural materials, optimization of energy conversion systems, solidification of fluoride salts, control of tritium, control of beryllium contamination, enrichment of lithium fluoride-beryllium fluoride salt, design of core refueling, and operation and control of pebble bed reactor. Based on the above, the focuses of research on FHR design are discussed, and areas of study for future development of FHR technology are recommended. This paper aims to provide a reference for the research and development of FHR in the future. 

Fluoride-salt-cooled high-temperature reactors: Review of historical milestones, research status, challenges, and outlook

40th Anniversary of the first international topical meeting on nuclear reactor thermal-hydraulics: Highlights of thermal-hydraulics research in the past four decades

Engineering demonstration reactors: A stepping stone on the path to deployment of advanced nuclear energy in the United States

The near and mid-term future of the existing Polish coal-fired power fleet is uncertain. The longer-term operation of unabated coal power is incompatible with climate policy and is economically challenging because of the increasing price of CO2 emission allowances in the EU. The results of the techno-economic analysis presented in this paper indicate that the retrofit of existing coal-fired units, by means of replacing coal-fired boilers with small modular reactors, may be an interesting option for the Polish energy sector. It has been shown that the retrofit can reduce the costs in relation to greenfield investments by as much as 35%. This analysis focuses on the repowering of a 460 MW supercritical coal-fired unit based on the Łagisza power plant design with high temperature small modular nuclear reactors based on the 320 MWth unit design by Kairos Power. The technical analyses did not show any major difficulties in integrating. The economic analyses show that the proposed retrofits can be economically justified, and, in this respect, they are more advantageous than greenfield investments. For the base economic scenario, the difference in NPV (Net Present Value) is more favorable for the retrofit by 556.9 M€ and the discounted payback period for this pathway is 10 years.

Kevin Johnson

Papers

Kairos power thermal hydraulics research and development

Neutronics, thermal-hydraulics, and multi-physics benchmark models for a generic pebble-bed fluoride-salt-cooled high temperature reactor (FHR)

Photoneutron production and characterization in fluoride-salt cooled high-temperature reactors