These two parts were issued separately, but are cataloged as a unit. The two compounds Na/sub 4/U/sub 3/F/sub 17/ and Na/sub 3/Th/sub 2/F/sub 11/ were found to have a face-centered cubic structure. From parameter dimensions and intensity values these two compounds appear to be isomorphous. Na/sub 5/U/sub 3/F/sub 17/ has an identical cell size with alpha -Na/sub 2//UF/sub 6/. A group of three compounds (Rb/sub 2/ThF/sub Rb/sub 2/ZrF/sub 6/, and CsZrF/sub 6/) were reliably identified as being uniaxial by use of their optical properties. These compounds were tentatively indexed on the basis of data obtained from powder x-ray spectrometer patterns found to best fit a hexagonal unit cell. (W.L.H.)

The reactivities of several U--Nb-- Zr alloys in the Sodium Reactcr Experiment are compared with that of 2.8% enriched U fuel. The alloys considered have the following compositions: 15% Nb--70% U--15% Zr; 12% Nb--82% U--6% Zr; and 6% Nb--82% U-- 12% Zr. Each alloy is studied at U enrichments of 3, 7, and 11%, and the alloy enrichments necessary to give the same reactivity as the 2.8% enriched U fuel are found by interpolation. (T.F.H.)

In order to facilitate reactor design studies a compilation of calculated two-group constants averaged over the infinite-medium flux produced by a fission source was made for approximately 80 materials of interest to reactor engineers. A comparison with available experimental age measurements is included. (auth)

The recent Windscale incident has emphasized the need for available light aircraft and proper instrumentation for aerial surveys following a release of large quantities of airborne radioactive materials. Early tests (1951 and 1955) are reviewed, and the program now in effect at the Oak Ridge National Laboratory is presented. (auth)

The combined attack of HNO/sub 3/ and HNO/sub 2/ on TBP-kerosene solvents used in the Purex Process produces degradation products that cause abnormal quantities of zirconium to be extracted along with the plutonium and uranium and thus limits the decontamination. (auth)

This report describes the development of work that began as an investigation of photosynthesis and that continues in this direction, but which has as a new product some entirely strngly results. Photosynthesis, the process upon which all life on earth today is ultimately dependent, achieves the conversion of electromagnetic energy from the sun into chemical energy in the form of plant material by the reduction of CO{sub 2} from the atmosphere with the liberation of O{sub 2} to the atmosphere. It has been possible to describe in some detail the way in which the plant accomplishes the reduction of carbon dioxide, using radioactive carbon as a tracer. The status of the present knowledge, and how they attained it, together with some prospectus of the future and what we can look forward to, is the principal theme of this discussion.

A compilation of available data on the spectra of thorium is presented, including energy levels and classified lines with Zeeman effects and isotope shifts, as well as certain data on unclassified lines. The present status of knowledge of these spectra is discussed. (auth)

Fission products, which may leak from the fuel and activated corrosion products from stainless steel surfaces, influence the design of several systems which support the main coolant system. Since the radioactivity in the main coolant resulting from these impurities must be limited to reasonable levels during operation, a purification system becomes important. Air conditioning of the vapor container as a result of possible main coolant leakage may be necessary during and after operation to remove airborne activity. After shutdown, treatment and disposal of active effluents becomes the function of a waste disposal system. Activities are tabulated, by individual isotopes, for 10,000 hours of full power operation. (auth)

The results of laboratory studies on sodium carbonate ion exchange are shown. The effect of salt concentration, uranium concentration, and possible interference with ion exchange from vanadium, molybdenum, sulfate and chloride are discussed. Various elution systems and the effect of residual uranium are described. A short discussion of ammonium carbonate ion exchange is also presented. (auth)

ABS>A series of seven flowsheet demonstrations of the Volatility Process was performed using nonirradiated material. In this series (a) the Pilot Pland was proven to be operable but not sufficiently reliable for remote operation; (b) the feasibility of a bed of NaF pellets as a trap for Cr aad Zr fluorides was demonstrated; and (c) the most desirable fluorine flow rate for fluorination of molten salt in the existing equipment was determined to be in the range 10 to 30 std. liters per min. (auth)

The steady-state energy distribution is obtained for a group of initially monoenergetic charged particles slowing down in a filly ionized gas. The distribution function is obtained analytically by solving the FokkerPlanck equation in energy space. With reference to thermonuclear reactions, the results obtained suggest that in some situations the contribution of the slowingdown distribution to the reaction rate may be significant. (auth)

The head-end system for the ARE salt was tested with barren salt and shown to be operable. Transfer of the final batch of salt by gravity flow from the bold tank was shown to be feasible with a redesigned feed salt freeze valve. The CRP trap was also redesigned but the remote dumping mechanism did not function properly. (auth)

The study of the toxicity of radium and radium decay products was continued. Special emphasis was placed on the acquisition of data on patients selected by record of exposure. Data are tabulated on the radium body burden of about 40 individuals. About half the measurements were made on living persons and about half on tooth or bone specimens. Case history summaries and all available medical data are summarized for persons under study. An investigation of the gamma shielding properties of dunite was continued. Design modifications and calibration of radiation detection instruments are discussed. (For preceding period see AECU-3504.) (C.H.)

Unclassified Engineering Materials List, TM-4100(lst Rev.), is a catalog of available U. S. Atomic Energy Commission unclassified engineering drawing materials on the peaceful applications of atomic energy. The engineering literature described in this publication includes drawing, specifications, photographs, bill of materials, cost analysis, design criteria, psrts lists, and supporting textual data. This consolidated list m- cludes all materials originally announced in TM-4100, January 1957, and TID-4100, Supplement 1, July 1957, and additional engineering data received and cataloged by TlSE after the original issuances. The entire publication, TID-4100 lst Revision Supplement 1, is devoted to the Shippingport Pressurized Water Reactor. (W.L.H.)

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A new method of introducing predetermined quantities of hydrogen into zirconium was developed and evaluated. The procedure is simple, effective, and inherently good in preverting oxygen and nitrogen contamination. Zirconium samples containing four levels of dissolved hydrogenated to 100, 300, 3500, and 7700 ppm hydrogen. Dissolved oxygen was found to decrease hydrogen absorption in both the alpha and beta modifications of zirconium. The effect of hydrogen on density, hardness, and microstructure was determined. X-ray-diffraction measurements were also obtained. (auth)

The compound RbU/sub 6/F/sub 25/ has a hexagonal crystal structure with the parameters a/sub o/ = 8.195 plus or minus 0.002 A and c/sub o/ = 16.437 plus or minus 0.002 A. This compound is believed to be isomorphous to KU/sub 6/F/sub 25/ and KTh/sub 6/F/sub 25/. (auth) uranium hexafluoride -chlorine trifluoride -hydrogen fluoride from a knowledge of the behavior of the three binary systems. The conditions under which chlorine trifluoride and hydrogen fluoride could be removed from uranium hexafluoride by fractional distillation are discussed. (auth)

The thenoyltrifluoroacetone (TTA) extraction method has been investigated for the determination of microgram concentrations of thorium in uranium ores and concertrates. The tolerance limits for eighteen elements commonly found in uranium ore concentrates were established. The effect of phosphate on estraction of thorium was studied. Cobalt, copper, tin, and bismuth were found to seriously interfere with the Thoron method for the determination of thorium after a TTA extraction. A TTA extraction method is described for the separation of thorium and uranium from the interfering ions, employing preliminary acid sulfide and ammonium hydroxide separations. The method is rapid, and results obtained compare favorably with results obtained with other procedures. (auth)

The objectives of the conference were to accomplish an interchange of information and study the determination of contact resistance. The effect of contacts on AEC production problems is discussed. Otber discussions are presented one applications of contact devices, present testing criteria, materials and process variables, process controls, and future development plans. (T.R.H.

Originally issued as S and P 1963A, Parts I and II. A design and feasibility study of a pebble bed reactorsteam power plant is presented, The reactor design which evolved from this study is a 125 Mwe heliumcooled two-region thermal breeder, operating on the uranium-thorium cycle, in which all core structural materials are graphite. Fuel is in the form of unclad spherical elements of graphite, containing fissile and fertile material. The primary loop consists of the reactor plus three steam generators and blowers in parallel. Nuclear characteristics, costs, etc., are given. (W.D.M.)

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The theory of energy transfer between charged particles in a fully ionized gas is reviewed, and calculations are made of the rate at which energy is transferred from electrons at a temperature T to cooler ions. The interaction between ion and electron is assumed to be of the Debye form (Ze/r) exp (-r/ lambda ), where lambda is the Debye shielding length. It is suggested that future improvements of the theory of Coulomb interaclions in ionized gases are likely to be made in two ways: through employing an effective potential derived on the basis of quantum statistics for the electrons and through improvements in the two-body approximation to the many-body problem. (auth)

For presentation at the American Chemical Society's Nuclear Technology Symposium, Boston, Apr. 5-10, Information is presented from studies with materials and conditions simulating those expected in anm aqueous homogeneous reactor for the formation of insoluble corrosion and fission products in aqueous UO/sub 2/ SO/sub 4/ solutions used as a reactor fuel. Sulfate salts which become insoluble as the temperature inereases deposited preferentially and reversibly on hot walls. Oxides from hydrolysis of sulfate salts deposit on any surfaces while insoluble corrosion products released into the solution show variable degrees of circulation. (auth)