Technical report presenting a summary of the flowsheets, equipment, and progress for the Oak Ridge National Laboratory (ORNL) pilot plant development of the Purex Process and of the ORNL Metal Recovery Program. As of this report, conversion of the Purex pilot plant equipment in Buildings 3019 and 3503 is 90% complete. The building structure for the ORNL Waste Metal Recovery plant had been completed, and 15% of the process equipment had been installed. The first hot runs for this plant were scheduled for June, 1951. [From Abstract; Introduction]

Abstract: "The potential of the Np(IV)-Np(V) couple is not directly measurement since the couple does not establish reversible equilibrium at an inert electrode. Reproducible potential measurements were obtainable, however, in solutions containing Np(IV), Np(V), Pe(II), and Pe(III) ions in oxidation-reduction equilibrium. The expected fourth power hydrogen ion dependence of the Np(IV)-Np(V) couple was confirmed over the range 0.25-1.0 molar perchloric acid concentration. The heat of the reaction NpO2+ + 1/2 H2 + 3H+ = Np-(+4) + 2 H2O in 1 molar perchloric acid solution was determined from the electromotive force temperature coefficient to be -36.3 +/- 0.3 kg.-cal. The formal potential of the Np(IV)-Np(V) couple is -0.746 v. at 25 degrees in 1 molar perchloric acid solution."

Discussing a reconnaissance carried out for uranium in parts of the San Juan Basin in New Mexico and Colorado

A report summarizing the geology of Crooks Gap, Fremont County, Wyoming, as related to Uranium Resources