The following report is a study of the separating qualities of a loop-type separator that can obtain separation with a smaller pressure drop.

"Changes, corrections and additions to the original report are included in this addendum. These are brought about by further development of the design by Blaw-Knox, ANL and ORNL. The changes are listed in accordance with the main headings, pages and paragraphs to which they apply."

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."

"The most hasardous conditions relating to the storage and handling of the SRE fuel are those in which water and fuel form a possible critical assembly. Therefore, this memorandum is primarily devoted to an analysis of the conditions necessary for a critical mixture of water and SRE fuel. Certain special geometries are then analyzed for their safeness."

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.).