Problems associated with the development of a multi-cell thermionic fuel element (TFE) with ability of electric heating test are discussed. A conceptual design of such TFE with trilayer emitter stack is proposed. Trilayer emitter stack consists of a strong emitter fuel clad coated with a high temperature oxide ceramic. Emitter tungsten coatings applied to a ceramic and they separated one after another by insulated gaps. Modern materials that should be base to build this trilayer emitter are presented. Results of calculational investigations of TFE output parameters are included. Results of the preliminary test of TFE and it’s components are presented. It is shown that proposed TFE conceptual design from one side allows to provide high output parameters inherent to multi-cell design, and from other side to gain advantages of single cell TFE, such as TFE and reactor nuclear safety, reliability, work cost savings.
