This report for March 1961, from the Chemical Processing Department at HAPO, discusses the following: Production operation; Purex and Redox operation; Finished products operation; maintenance: Financial operations; facilities engineering; research; and employee relations.

Report presenting a table of corrected optical pyrometer readings which enables optical pyrometer users to convert observed temperature immediately to the true temperature, if the effective emissivity of the material being observed is known. The table gives observed temperatures from 1,000 to 3,000ºK in increments of 5 degrees, from 3,000 to 5,000ºK in increments of 10 degrees, from 5,000 to 10,000ºK in increments of 50 degrees, and from 10,000 to 39,900ºK in increments of 100 degrees. For these, true temperatures are tabulated for 49 emissivities ranging from 0.02 to 0.98 in increments of 0.02.

Three Pu preparations were made and partially characterized. These preparations were one pure PuO/sub 2/ preparation via the batch-oxalate route and two PuO/sub 2/-UO/sub 2/ preparations containing 0.5 and 20 at.% PuO/sub 2/ via the continuous coprecipitation route. The PuO/sub 2/ preparation, which had the largest surface area of the preparations (29 m/sup 2//g), tended to pick up weight when exposed to the box atmosphere. Dry pressing and sintering studies were conducted on the PuO/sub 2/ preparation. The results indicate that the sintered density of PuO/sub 2/ pellets is independent of green density above 5.6 and 6.0 g/cm/sup 3/ for pellets sintered at 1600 and 1400 deg C, respectively. Preliminary reactor physics calculations for near-thermal reactors indicate that extremely long core lives can be attained with a fuel of initial composition 78 at.% Pu/sup 239/, 12 at.% Pu/sup 240/, and 10 at.% Pu/sup 24 / 1>s, and that the reactivity variation during core life is nominal. (D.L.C.)

A system for measuring depths of cryogenic liquids is described. The indicating device is a modified differential pressure gage. The level sensing probes are of various types, either permanent or removable. The heat leak to cryogenic liquids may be made negligibly small.