Progress report of the Oak Ridge National Laboratory Analytical Chemistry Division providing updates on various projects, experiments, and other work in ionic analyses, analytical instrumentation, radiochemical analyses, activation analyses, spectrochemical analyses, inorganic preparations, optical and electron microscopy.

Two 500-kw fused-fluoride-to-Nak heat exchangers, two 500-kw NaK-to-air radiators, and a 20-tube high-velocity heat exchanger were fabricated for a heat-exchanger development program. A construction procedure, utilizing both inert-arc-welding and high temperature dry-hydrogen brazing, was used successfully on all of the units. The tube-to-header joints were welded and back-brazed; the manifold joints were inert-arc-welded with full penetration; and the tube-to-fin joints were brazed. A detailed description of the fabrication of each type of component is discussed and a cost analysis of the 500-kw units is presented.