[en] The United States has conducted extensive irradiation testing on fuels, structural, and absorber materials as a part of the breeder reactor program. Tests have been directed toward basic technology related to fuels and materials, confirmation of material and design selections, and reactor safety analyses. The test reactors used most extensively have been the EBR-II, TReAT, and ETR reactors. The FFTF will be available in the near future and will provide flux levels and test capabilities not previously available in the U.S. The FFTF and EBR-II, sodium-cooled fast reactors rates at 400 and 63 Mwth respectively, are used for steady state irradiations. TREAT and ETR are thermal reactors with provisions for conducting transient tests in special sodium loops. An overview of the design and fabrication of various irradiation test vehicles used in the U.S. Breeder REactor Porgram is presented. The test vehicles described have been selected to demonstrate the variety of irradiation tests conducted