A preliminary hybrid 1A flowsheet in which the extraction section operates substantially acid while the scrub section is acid deficient is presented. The effects of added nitric acid on the performance of the acid deficient 1A flowsheet are considered, and the need for control of the entering stream acidities in such flowsheets is evaluated. Data on batch-countercurrent decontamination and plutonium recovery are included. (J.R.D.)

Measurements of the proton-proton differential scattering cross section using 340 Mev protons show a cross section approximately constant between 41{sup o} and 90{sup o} in the center of mass system. Two methods of counting the scattered protons have been used. The first method uses a counter telescope to count the scattered protons. The second method utilizes coincidences between counters which record the two protons involved in a single scattering process. The first method gives slightly higher cross sections; the average value of the differential cross section is (5.5 {+-} 1.0) x 10{sup -27} cm{sup 2} steradian{sup -1} in the center of mass system. Although the scattering appears isotropic it is larger than can be accounted for with pure S-scattering. There is a strong suggestion, but no positive proof, that n-p and p-p forces are different.

The extraction of radium from uranium residues was proposed either by the use of the old (Curie) process or by the development and use of a new process. Qualitative procedures for the extraction of radium from pitch-blende are found recorded in the literature but little quantitative data are available. In order to become acquainted with the process and techniques involved, an attempt was made to use the method developed by the Curies, which essentially is being used by the Eldorado Gold Mines, Limited, Port Hope, Ontario.

BS>The preparation of niobium was attempted by a number of chemical and electrochemical routes. Chemical reduction of oxides and halides such as Nb/sub 2/O/sub 5/, K/sub 2/NbOF/sub 5/, K/sub 2/NbF/sub 7/, and NbCl/sub 5/ was conducted with varying degrees of success. Aqueous electrochemical reduction has not yet yielded a metallic deposit. The electrolysis of molten baths containing K/sub 2/NbOF/sub 5/ or K/sub 2/NbF/sub 7/ produced niobium metal. The more promising methods of preparation for Nb metal at the present time include the reaction of Nb/sub 2/O/sub 5/ with C, the H/sub 2/ and active metal reduction of NbC1/sub 5/, and electrolysis of K/sub 2/NbF/sub 7/- NaC1 melts. (auth)

Some of the properties of rare earth hydrides are reviewed. Information on the hydrides of Tm, Lu, Tb, and Ho is not included because no work has been done on these elements. Eu and Yb are different from other rare earths in that MH/sub 2/ is their highest hydride and the crystal structures of EuH/sub 2/ and YbH/sub 2/ are orthorhombic. ra, Ce, Pr, and Nd form a dihydride which will take hydrogen into solid solution up to MH/sub 3/ without a change in crystal structure. The heavy rare earths form the same type of dihydride as the light, but as the hydrogen content increases from MH/sub 2/ the cubic structure becomes unstable and is replaced by a hexagonal structare. With increasing atomic number, thermal stability and hydrogen deusity increase. (J.R.D.)

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Since the end of the war when the long-lived isotope of carbon, C{sup 14} became available a new tool has been applied in the study of photosynthesis. Because of the interest evoked by the tracer method, research in all areas of photosynthesis has expanded. There have been reviews on various aspects of photosynthesis such as the primary photochemical reaction, quantum efficiency products, and comparative biochemistry, many discussions of which were included in the monograph of The American Society of Plant Physiologists, ''Photosynthesis in Plants''.

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Neutron density at the end of the slug is increased appreciably and therefore the heat production in the end of the slug is also increased. The end result is increased heat flow into the cap with correspondingly higher temperatures. The combined results and conclusions of documents CP-1580, CP-1989, and CP-2871 afford a means of calculating the aluminum end cap temperatures with consideration being give to the above mentioned {open_quotes}Wilkins effect,{close_quotes} i.e., that the heat production near the end of a slug with an aluminum end cap is greater than the heat production at the middle (axially) of a slug. The maximum temperature in the aluminum end cap is calculated to be about 278{degrees}F. for the {open_quotes}G{close_quotes} Pile. This temperature occurs at the center of the maximum performance process tube.

This document is an index of classified reports from The University of Rochester Atomic Energy Project for the period, January 1948 to December 1949. Work was in the general area of health and biology.

This document is the progress report for the design and development of Pile Area {open_quotes}G{close_quotes}, to cover the period June 1, 1949 to December 31, 1949. This project represents the major effort of the Reactor Division of the Design and Construction Divisions. It is being pursued with the aim of being able to incorporate the major project objectives in a finished pile design if that design is begun about January, 1951.

Regarding heat transfer studies of annular spaces around the process tube, there is general agreement among all concerned, that high graphite temperatures are essential at the initial startup. Pile Technology, in studying graphite damage, has developed information that shows little or no expansion occurring when temperatures are maintained at 275{degrees}C. Stored energy levels are less than 5% and K/Ko has saturated in the region of 3.5 to 4. Badly expanded samples (1% increase in length) have recovered 75%. This, of course, is in the pile, since nonlinear annealing is necessary, temperature alone not being sufficient. You may refer to HW-14522, HW-14310 and HW-13117 for further discussion of these points. Based on this assumption we should select some minimum startup temperature, for the edge of the active zone, say 200{degrees}C as a starting point.

Pile Engineering reports on: metal deformation studies, status of group I metal, flow laboratory activities, boroscope inspection details, pile control details, elimination of silica feed, controlled exposure temperature for graphite samples, naval fuel test channel, strength of masonite at elevated temperatures, carbon dioxide pile temperature, H pile graphite temperature, sampling of pile graphite, special pile motion measurements, pile expansion, far side restraining clamps, vortical thimble thermocouples, and boiling studies. The Physical Chemistry Group reports on: pile annealing studies, thermal annealing studies, empty process tube temperature, X- ray line broadening, X-ray diffraction studies, the CSF program, the WSF program, and higher temperature exposures.

A low temperature adiabatic cryostat for determining precise calorimetric data has been described. The accuracy of the data produced by this apparatus has been established by measuring the thermal properties of n-hexane up to 300 deg K. These data agree with available precise data, in general, to within 0.2%. The precision of the heat capacity measurements is, for the most part, better than 0.1%. (auth)

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This HAPO report discusses the toxic effects of methyl isobutyl ketone, known commercially as hexone. Explosive limits are discussed, in addition to animal experimentation results.

Malonate has been found to inhibit the formation of malic acid during short periods of photosynthesis with radioactive carbon dioxide. This result, together with studies which show the photosynthetic cycle to be operating normally at the same time, indicates that malic acid is not an intermediate in photosynthesis but is probably closely related to some intermediate of the cycle. Absence of labeled succinic and fumaric acids in these experiments, in addition to the failure of malonate to inhibit photosynthesis, precludes the participation of these acids as intermediates in photosynthesis.

When it became apparent that particles were emanating from the stacks of the separations plants, it become important that the source, size, activity and composition of the particles be determined in order to evaluate the hazard to persons working in and neer the stack areas. The present report will give the results of radiochemical analysis of particles collected by electrostatic precipitation from ``B`` plant canyon ventilation air, not from the off-gas ventilation line. Of importance is the fact the particles analyzed consist not only of particles from the ventilation air but also, unavoidably, of rust from the iron manifold used to conduct the gases to the precipitator. This makes a determination of the activity versus weight ratio impossible, but should not invalidate the radiochemical data.

Recent attempts to separate fission products from urine salts in a form suitable for measurement by beta counting have involved the use of ion exchange resins to remove the ions present in macro quantities leaving the trace elements behind as a {open_quotes}thin{close_quotes} sample for counting techniques. The separation of Cs from Na and K was chosen as the starting point because of the relative difficulty of separating these elements with ordinary chemical techniques. This report describes the testing of a method for the separation of cesium from macro quantities of sodium and potassium using the ion exchange resin Dowex 50. The results obtained on the preliminary work with solutions containing only the elements in question were deemed of sufficient interest to warrant reporting separately. Other difficulties from interfering ions in urine are now being studied.

As part of the program for obtaining data to extend the scope of the systematics of alpha-radioactivity and to obtain more data pertaining to the energy surface in the heavy region of elements, they have made some pertinent new measurements on protactinium isotopes. The heaviest isotope of protactinium hitherto reported is that of mass 234 and hence it would be of interest to know the beta-emission properties of heavier isotopes in order to tie them in with the known radioactive data in this general region. Since low-energy deuteron bombardment of U{sup 238} might be expected to lead to Pa{sup 235} and Pa{sup 236} by (d,{alpha}n) and (d,{alpha}) reactions and proton bombardment to Pa{sup 235} by the (p,{alpha}) reaction, these irradiations were made in the 60-inch cyclotron at energies of 19 and 9.5 Mev, respectively. The protactinium was chemically separated following the bombardment of natural uranium by a procedure which involved a number of manganese dioxide cycles coupled with extractions of protactinium from aqueous into organic solvents. The manganese dioxide cycles consisted of precipitating this compound from the solution of uranium in nitric acid, followed by centrifugation, dissolution of the solid with hydroxylamine solution, dilution, and reprecipitation. The dissolved precipitate from …

The maximum nuclear accident which could occur in a Na-cooled, Be moderated, Pu and power producing reactor is estimated theoretically. (T.R.H.) 2O82 Results of nuclear calculations for a variety of compositions of fast, heterogeneous, sodium-cooled, U-235-fueled, plutonium- and power-producing reactors are reported. Core compositions typical of plate-, pin-, or wire-type fuel elements and with uranium as metal, alloy, and oxide were considered. These compositions included atom ratios in the following range: U-23B to U-235 from 2 to 8; sodium to U-235 from 1.5 to 12; iron to U-235 from 5 to 18; and vanadium to U-235 from 11 to 33. Calculations were performed to determine the effect of lead and iron reflectors between the core and blanket. Both natural and depleted uranium were evaluated as the blanket fertile material. Reactors were compared on a basis of conversion ratio, specific power, and the product of both. The calculated results are in general agreement with the experimental results from fast reactor assemblies. An analysis of the effect of new cross-section values as they became available is included. (auth)

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