The exchange reaction between water and hydrogen sulfide was one of a number of reactions investigated by Urey and co-workers at Columbia University from 1940 to 1943 for possible

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1 HYDROGEN I SULFIDE I RECYCLE

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Figure 13.26 Simplified illustration of dual-temperature principle.

use by the Manhattan District for heavy-water production. During this time, Spevack [S6] conceived and patented the dual-temperature process and suggested its use with the water- hydrogen sulfide system. Because of concern about corrosion by aqueous solutions of hydrogen sulfide, the process was not used by the Manhattan District.

In 1949, when the need for large amounts of heavy water for the Savannah River reactors of the U. S. AEC was recognized, E. I. du Pont de Nemours and Company selected this process as the most economical means for producing heavy water on the large scale then required.

Spevack [S7] had developed improvements in the process that reduced its energy consumption, and corrosion research established where it was necessary to use stainless steel and where carbon steel could be used without undue corrosion by hydrogen sulfide. Under duPont direction the Girdler Corporation designed a plant to produce heavy water at Dana, Indiana, where some of the equipment formerly used for the Manhattan District’s water distillation plant was available. The process came to be known as the GS process, for Girdler-Sulfide. Lummus designed and du Pont built a second GS plant at Savannah River, of about the same capacity as the Dana plant. Both plants came into operation in 1952. By 1957, production rates were 490 MT/year at Dana and 480 MT/year at Savannah River. At this time the demand for heavy water began to decrease; the Dana plant was shut down and dismantled, and two-thirds of the GS units at Savannah River were shut down and put into standby condition. In 1977 the production rate from the operating portion of the Savannah River plant was 69 MT/year.

At both Dana and Savannah River the GS process was used for primary concentration of deuterium to 15 percent, with the remaining concentration being effected by distillation of water and electrolysis.

Pilot-plant investigations of the GS process have been carried out in France [R4] and in Sweden [E2], and a thorough analysis of the process has been published by Weiss [W3].