Concerning advantages in using 208Pb as such a FR coolant

In the paper cores of two fast reactors with heavy liquid metal coolant are considered. The first object, RBETS-M, is a project of a medium power, 900 MW, reactor cooled with lead-bismuth. The second object, BRUTS, is a project of an ultra-small power, 0.5 MW, reactor cooled with lead. The results of replacement of their standard coolants with the lead coolant enriched up to 100% with 208Pb are presented. In the RBETS-M core having a large coolant volume share this replacement results in sufficient increasing the share of 238U involved in the fission process and respective decreasing the share of 239Pu and 241Pu burning.