The attenuation of electro-statically and electro-magnetically shielded rooms in the ``E,`` ``R,`` ``I,`` and ``T`` Buildings was measured so that corrective measure could be taken if the attenuation was found to be low. If remedial measures could not be taken, the shortcomings of the rooms would be known. Also, the men making the measurements should oversee construction and correct errors at the time. The work was performed by measuring the attenuation at spot frequencies over the range of from 150 kilocycles to 1280 megacycles with suitable equipment mounted in small rubber-tried trucks. The attenuation was determined by ``before and after`` shielding and/or ``door open and door closed`` measurements after installation of copper shielding. In general, attenuation in the frequency range of approximately 10 to 150 mc. was good and was of the order expected. At frequencies in the range of 150 mc. to 1280 mc., the attenuation curve was more erratic; that is, at certain frequencies a severe loss of attenuation was noted, while at others, the attenuation was very good. This was mainly due to poor or faulty seals around doors and pass windows. These poor seals existed in the ``T,`` ``E,`` and ``I`` Buildings because the doors were …

The Purpose of this manual is to describe preparation of bismuth powder for use in process operations. Bismuth powder is to be prepared in Room 232 of ``T`` Building where all necessary apparatus is installed.

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On February 4 at a conference in T.C. Gary`s office attended by Messrs. Wood, Gary, H.T. Daniels, Burns and C.R. Johnson, the design of the strap plates on the front and rear shields of the pile was discussed from the standpoint of welding technique in the field. Discussion of the design centered about the plug welding of the plates to the Laminated blocks and the ability of the field to perform this work properly. It was decided that welding specialists should be consulted prior to the beginning of the actual field erection in order that the best technique could be employed to guarantee good workmanship. It was agreed that a conference with such specialists should embrace both the features of the design as well as the practical phases of welding itself. This report provides details of this conference.

Experiments were carried out for the purpose of increasing production, efficiency, and purity of uranium metal. The electrolytic method as described by Driggs and Lilliendahl for the preparation of uranium metal was followed with but little deviation. The yield of metal at the very best was only 50%. The metal powder produced, at times, was very pyrophoric. Methods were found whereby the metal, at least in part, can be made from the oxides with an average yield of about 90%. The small amounts of sludge and slag accumulated in this modified process can readily be re-used in the electrolysis pot and, therefore, an overall yield of 96% can be obtained. Information accumulated from these experiments has been compiled in such a manner as to be readily available for factory use, for patent purposes and for future publication.

The Site B Foundry is equipped for the melting and casting of tuballoy and its alloys. Castings weighing up to 750 pounds and as long as 40 inches can be made. Melting can be carried out in the vacuum, in inert gases or under fluxes. Heating is by high frequency induction. A description of the generally foundry layout, the furnace construction and operation, and of the auxiliary equipment is given in this report. The casting technique used in the Site B Foundry is designed to minimize piping and cold shuts in the billets. The top of the mold is kept hot and freezing of the billet takes place from the bottom. This hot topping minimizes piping. Controlled pouring into warm molds minimized cold shuts.

In the ether extraction process, as originally developed, purified uranium dioxide was obtained by evaporation and calcination of the uranyl nitrate solution, followed by calcination of the resultant UO{sub 3}. It was suggested that an alternate procedure might be developed, involving the precipitation of uranium from the nitrate solution as ammonium diuranate. This material could then be calcined to uranosic acid, or reduced directly to the dioxide. It had already been established that ammonium diuranate could be precipitated completely from uranyl nitrate solutions. Experiments were carried out to determine whether a basic nitrate, analogous to a known sulfate salt, would be formed in the process. Both direct reduction of the diuranate to UO{sub 2} and calcination to uranosic acid were investigated to determine the physical characteristics and residual nitrogen of the resultant brown oxide.

In the treatment of carnotite concentrates, sodium diuranate was prepared by acidifying tricarbonate liquors to eliminate carbon dioxide, and then precipitating the sodium salt by the addition of caustic. Direct precipitation of uranium by the addition of caustic to tricarbonate liquors was used when pitchblende ores were processed, because this procedure was more effective in giving a product with a low molybdenum content. Tests of this method in the laboratory and Pilot Plant indicated that low uranium losses (0.2 to 0.3%) would be encountered with typical liquors if 1.7 to 2.0 lbs of caustic were added for every pound of uranosic oxide in solution. Since losses as high as 3% were incurred in plant operations, further work was undertaken, in an effort to reduce the uranium concentration in the waste liquors.

Results of type II UF/sub 6/ centrifuge operation are presented. Data from this type operation in a single unit are useful in predicting the operation of a number of centrifuges in cascade. (J.R.D.)

This is a monthly progress report on the following programs: (1) 184-inch Cyclotron; (2) 60-inch Cyclotron; (3) Synchrotron; (4) Linear Accelerator; (5) Experimental Physics; (6) Theoretical Physics; (7) Isotope Research; (8) Chemistry; (9) Medical Physics; and (10) Health Physics and Chemistry.

A scheme of glucose degradation has been validated by the use of intermediates of known isotopic composition. In this scheme: glucose {yields} lactic acid {yields} CO{sub 2} (C-3,4) + acetic acid {yields} CO{sub 2} (C-2,5) + acetone {yields} iodoform (C-1,6) + acetate (C-1,6; 2,5), it was found that (a) in the oxidation of lactic acid, approximately 4.7% of the acetic acid was oxidized to CO{sub 2}; and (b) under the conditions prescribed, BaCO{sub 3} from the degradation of Ba acetate contained approximately 1.5% of the activity of the methyl group.

The procedure for estimation of heats of formation of compounds is illustrated by discussion of compounds of several of the elements of the actinide series. The procedure is particularly suited for lanthanide and actinide elements because of the similarity of the ionic radii and types of bonding.

This quarterly report discusses the following topics: (1) the metabolic properties of plutonium and allied materials; (2) biological studies of radiation effects; (3) biological effects of radiation from external and internal zones; and (4) health chemistry.

Much of the cloud chamber work has been directed toward obtaining the angular distribution of protons bombarded by deuterons from the 184-inch cyclotron. The observations have been restricted to those protons arising from neutrons of energy greater than 65 Mev. The cloud chamber used for this work is of 16-inch diruneter and employs a magnetic field of 14000 gauss. The chamber is filled with hydrogen at a pressure of 1/2 atmosphere; the vapor used is water and alchohol. Nearly 800 proton tracks were measured and calculated before analysis of the data indicated that the measuring procedure should be revised. They gave the angular and energy distributions shown in Figures 1 and 2. The discrepencies between the theoretical and experimental energy distribution of the neutrons shows that serious errors were being made. As a first check of possible sources of error, random parts of the data were remeasured. They indicated that errors in the measurements of the angles were being made that gave a mean deviation of about {+-} 2{sup o} in the beam angle and {+-} 4{sup o} in the dip angle. These errors were largest at large scatter angles. In addition, a more serious error occured in the measurements …

It has been suggested in the past that special numbers of neutrons or protons in the nucleus form a particularly stable configuration.{sup1} The complete evidence for this has never been summarized, nor is it generally recognized how convincing this evidence is. That 20 neutrons or protons (Ca{sup40}) form a closed shell is predicted by the Hartree model. A number of calculations support this fact.{sup2} These considerations will not be repeated here. In this paper, the experimental facts indicating a particular stability of shells of 50 and 82 protons and of 50, 82, and 126 neutrons will be listed.

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A detailed description of the processing of pitchblende ores used at the Port Hope, Canada, refinery is given including both the recovery and purification of U and Fu. The health hazards present in the processing are discussed, and recommendations are made which will insure adequate health protection. (L.T.W.)

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The bomb reaction slag produced at the ElectroMetallurgical X metal plant is at present divided into rich C-1 slag and lean C-2 slag by merely screening through a 4 mesh wire screen, the "on 4 mesh" material becomes the C-1 slag and the "thru 4 mesh" material becomes the C-2 slag. In the experiments covered by this report it was found that the concentration of the lean C-2 slag could be facilitated by the use of a 20 mesh screen for the slang separation in place of the 4 mesh screen, as the 20 mesh screen removed troublesome, small, hard lumps which passed the 4 mesh screen. Furthermore, it was found that the additional small lumps removed by the 20 mesh screen were just as rich in X metal as the larger lumps which make up the bulk of C-1 slag.