Effect of 37Cl enrichment on neutrons in a molten chloride salt fast reactor

• Published in: Nuclear science and techniques Vol. 31; no. 3
• Main Authors: He, Liao-Yuan, Li, Guang-Chao, Xia, Shao-Peng, Chen, Jin-Gen, Zou, Yang, Liu, Gui-Min
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 2020
• Subjects: Energy; Hadrons; Heavy Ions; Nuclear Energy; Nuclear Physics; enrichment; Th–U fuel breeding; Molten salt reactor; Molten chlorine salt fast reactor
• ISSN: 1001-8042; 2210-3147
• DOI: 10.1007/s41365-020-0740-x

A molten chloride salt fast reactor (MCFR) is well suited to fuel breeding and the transmutation of transuranium (TRU) elements owing to its advantageous features of fast neutron spectrum and high TRU solubility. However, the neutron absorption cross section of 35 Cl is approximately 1000 times greater than for 37 Cl , which has a significant impact on the neutron physical characteristics of a MCFR. Based on an automatic online refueling and reprocessing procedure, the influences of 37 Cl enrichment on neutron economy, breeding performance, and the production of harmful nuclides were analyzed. Results show that 37 Cl enrichment strongly influences the neutron properties of a MCFR. With natural chlorine, 233 U breeding cannot be achieved and the yields of S and 36 Cl are very high. Increasing the 37 Cl enrichment to 97% brings a clear improvement in its neutronics property, making it almost equal to that corresponding to 100% enrichment. Moreover, when 37 Cl is enriched to 99%, its neutronics parameters are almost the same as for 100% enrichment. Considering the enrichment cost and the neutron properties, a 37 Cl enrichment of 97% is recommended. Achieving an optimal neutronics performance requires 99% 37 Cl enrichment.