In the 90s of the last century, in the breeding nurseries of the Novozybkov Agricultural Experimental Station, samples with a relatively low concentration of cesium-137 in the seeds and green mass of yellow lupine were selected: 4-83, SN-1408, 52-87-2113, variety Kastrychnik, etc. They were involved in hybrid combinations and received numbers 1-00-2-9, 1-02 and 10-04, 7-09, 8-12, which have been repeatedly used as parental forms in crosses in recent years. Studies have shown the possibility of obtaining positive results in blocking the accumulation of cesium-137 at the early stages of the breeding process, which contributes to the preservation of valuable material for further study during hybridization and the creation of yellow lupine varieties with the lowest possible content of 137Cs in the final product. For 2018–2019 varieties of hybrid origin of yellow lupine with a consistently low accumulation of cesium-137 in the grain were identified, regardless of the density of soil pollution: 5-14-11 (112 and 243 Bq/kg), 5-12-92 (206 and 221 Bq/kg), 13-10-96 (270 and 243 Bq/kg), 15-10-7212 (235 and 271 Bq/kg). Despite the higher density of soil contamination by 13–33% in 2019, in the hybrid material 2-08-57, 4-08-116, 11-10-65 and 12-10-66, the concentration of 137Cs in grain decreased by 63% with indirect participation in crosses of variety samples selected in 1994–1996. In 2020, the analysis of 13 samples showed a significant decrease in the accumulation of cesium-137 in grain to 61–136 Bq/kg, regardless of the decrease (8–34%) or increase (5–46%) in the density of soil contamination relative to 2018–2019, as well as grain yield. Stability in terms of the content of cesium-137 in the green mass was not obtained: in 2018, out of 60 samples, 12 variety samples fit into the standard for dry matter (400 Bq/kg), in 2019 they were absent due to the low yield of green mass. Accessions 5-12-92, 5-14-11, 13-10-96, 4-08-116, etc. were included in crosses as parental forms, and the resulting offspring are being tested in hybrid and breeding nurseries for the purpose of research on blocking the accumulation of 137Cs in yellow lupine grain. It has been established that within three years the lowest radionuclide content in yellow lupine grain was obtained from samples 5-12-92 and 5-14-11, with which seed nurseries for testing offspring will be established.