The Thermionic Fuel Element (TEF) Test Rig is designed for non‐nuclear testing of single‐cell TFEs, utilizing electric heaters as part of the Thermionic System Evaluation Test (TSET) Facility (Woldet al.1994). Certification of the American specialists as well as testing the TOPAZ‐II TFEs at high power levels has resulted in a significant step forward in the technology transfer process. This paper will discuss high power operations that were performed in Russia as compared to high power operations recently conducted at the TSET Facility. This paper will also discuss modifications made to the system to support the SC‐320 (40‐kW single‐cell TFE) test. © 1995American Institute of Physics