Abstract: Critical experiment studies were performed, varying the parameters U235, B10 and metal to water ratio, in the SM-2 7 x 7 core configuration with 38 stationary elements and seven control rods of the SM-1 (APPR-1) type. An experimental mock-up of the SM-1 was assembled using the basic SM-2 fuel plates. Excellent agreement between the SM-1 boron loading, determined by chemical analysis, and the SM-1 mock-up boron loading, for equivalent bank positions, was noted. Several SM-2 mock-ups, cold clean and midlife, were assembled and studied with regard to reflector effects, flow divider effects, relative control rod array worths, critical rod configurations, and relative power distributions. The results of these experiments indicate as satisfactory a U235 loading of 36.4 Kg and a B10 loading of 63.4 grams for the SM-2. Attention is drawn to numerous power peaks present in the active core. The open seven control rod array has a slight reactivity advantage over the closed seven array and consequent minor disadvantage with respect to "stuck rod" criteria.

Progress report discussing projects and work completed by the University of Michigan Department of Chemistry 1957-1958.

Abstract: "A general description is given of the permanent zirconium plant at Y-12. Equipment is described and materials of construction are listed. Photographs illustrating principal equipment and reduced construction drawings are also presented. Operating conditions and costs information are listed."

From abstract: "This report contains a summary of the latest improvements in zirconium purification as developed by the Y-12 research, pilot plant, production, and engineering groups, all of whom have been generously cooperating in this project."

Abstract: A re-evaluation of the cost of producing essentially hafnium free zirconium as zirconium oxide at a rate of 150,000-200,000 pounds zirconium per year by solvent extraction of the metal thiocyanates in a permanent plant has been made. Using part of the present temporary facilities, the cost, with five year amortization of the plant, will be $3.15 per pound zirconium. A by-product of the mixed oxides of hafnium and zirconium, having at least fifty percent hafnium and perhaps as high as ninety percent hafnium, can be made available with little additional cost.

Abstract: Use of the mixer-settler apparatus as a rapid means of determining improved conditions for plant operation is described including the experimental details. The preparation of highly purified samples of both zirconium oxide and hafnium oxide is discussed. (This document is concerned almost entirely with explorations of small scale continuous systems. Another document dealing with this general problem using small scale batch operations is being published simultaneously. It should prove of advantage to the reader to study this companion report, Document Y-611, by Barton, Overholser, and Grimes, to obtain a complete picture of the available information.).

A report on using aluminum titanate as a ceramic materiel.

"This document includes papers covering technical problems involved in the design, construction and operation of the APPR-1" (p. 4).

Air filter and rainwater collections of atmospheric fall-out were made at Atlanta, Georgia; Urbana, Illinois; Topeka, Kansas; Fort Worth, Texas; and Nashville, Tennessee. Collections reflect the effects of the radioactive cloud from the Nevada tests.

Report that describes work performed by by the Hanford Laboratories Operation on the Plutonium Recycle Program during the Fiscal Year.

Development of more reliable, lower cost components for high temperature liquid metal-cooled reactor plants.

Analytical methods for the presence of the refractory substances in sodium are described.

Various hazards associated with the APPR-1.

An electromagnetic eddy current instrument is described that is capable of measuring copper and nickel plating 1 to 8 mils thick plated on bismuth mandrils of various sizes and shapes.