Operating experience with an experimental nuclear heated thermionic converter

Abstract

A rig has been developed for the testing of nuclear heated thermionic converters, which allows direct determination of the converter efficiency by measuring the waste heat flow through three thermal bridges. A 50 hr in-pile test of the device was performed in December, 1963. The converter consisted of a cylindrical molybdenum emitter and a niobium collector, with an electrode spacing of 0·5 mm. The emitter was heated by radiation from a (UZr)C fuel pin. The converter operated for 45 hr, with electrical power outputs between 30 and 40 W for most of the time, and with efficiencies of up to 11 per cent. At the end of this period a permanent partial short occurred in the converter.