One of the major factors restricting reactor power levels is the incidence of ruptured slugs. The primary purpose in studying ruptures is to determine how reactor operating variables affect rupture rates. With this knowledge reactor operating conditions may be adjusted or controlled in the manner that will optimize reactor production. In addition, knowledge of rupture rate relationships are useful in fuel element development and in overall economic studies of existing and proposed reactors and reactor processes. This report is a compendium of various types of rupture information largely developed during the past eighteen months. Plant rupture experience for CY-1957 is reviewed; rupture rate correlations with reactor variables for solid natural uranium material are presented; a comparison between solid and cored natural uranium material rupture rates is made; the basis for current discharging practice of rupture-prone metal lots is discussed. 11 figs., 2 tabs.

Corrosion tests were made on nickel-base brazing alloys containing boron snd silicon in fused fluoride fuels, liquid metals, nnd oxidizing atmospheres. Impoverished regions, after the tests, contained, approximately one third the original amount of boron and silicon that was present before the tests. (A.C.)

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)

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In accordance with the agreement in a meeting with Aerojet-General Nucleonics representatives, certain information is presented for use in planning the first DR Gas Loop test run. Included are the following: estimates of test section power prediction uncertainty and variation during run; estimates of limiting test section design powers and {Delta}P`s, presented as variables versus maximum loop flow as a parameter; spatial relation between in-pile tube and reactor surroundings; and a representative relative flux traverse in the sample space. The user of this information is cautioned to study the discussion to fully understand the significance of what is presented.

An endurance test was made to determine the reliability of the Mark ll control rod drive. The control rod drive unit completed 1300 scrams and the results are presented. (W.L.H.)

The basic information about the path of carbon in photosynthesis is reviewed together with the methods that were used to discover it. This has led to the knowledge of what is required of the photochemical reaction in the form of chemical species. Attention is then directed to the structure of the photochemical apparatus itself insofar as it is viewable by electron microscopy, and some principoles of ordered structure are devised for the types of molecules to be found in the chloroplasts. From the combination of these, a structure for the grana lamella is suggested and a mode of function proposed. Experimental test for this mode of function is underway; one method is to examine photoproduced unpaired electrons. This is discussed.

This report describes the operation of the fuels preparation department for the month of August 1958. Manufacturing employee relations, process development, plant improvements and financial operations are described.

This report describes the operation of the fuels preparation department for the month of September, 1958. Manufacturing employee relations, process development, plant improvements and financial operations are described.

Information available from HRP-CP development studies was summarized amd used as a basis for predicting the probable behavior of corrosion and fission product solids in the HRT and its associated chemical processing plant. Operation of the chemical plant will probably limit the HRT circulating solids concentration to between 10 and 100 ppm; quantitative predictions are uncertain due to uncertainties concerning the charaeteristics of reactor solids and the effects of rcactor geometries. (auth)

The JOFIT code fits, by a least squares technique, the curve y = A J/sub o/STAB(x-C)! from 4 to 500 points of observed data, computing the parameters A, B, C and the standard deviation of the final values of A, B, C, i.e., S/sub A/, S/ sub B/, S/sub C/. It is also possible to investigate the error in a region about the final values of A, B, C by computing the sums of the squares of the residuals at a series of points in this neighborhood. Typical computing and editing time for a 50 point problem is 2 minutes. Any size IBM-704 computer is adequate, and drums and tapes are not used. (auth)

Various mechanical-property measurements on several grades of manufactured (polycrystalline) graphite stock include tensile-strength determinatftons at temperatures from 20 to 2400 deg C (plus a few at 2500 deg C), tensile stress-strain and creep tests in the range 2000 to 2400 deg C, torsional strength and stress-strain measurements from 20 to 2600 deg C, torsional creep and stress-relaxation tests in the range from 2000 to 2500 deg C, dynamic Young's- modulus determinations from 20 to 2450 deg C, and evaluation of average coefficients of linear thermal expansion for the ranges 20 to 1050 deg C and 1300 to 2400 deg C. The materials studied include a Grade H4LM) molded in 36-in.-diam pieces, both as the standard stock with a nominal density of 1.74 g/cc and as stock re-impregnated to a nominal density of 1.80 to 1.85 g/cc, and four grades of graphite manufactured by the Los Alamos Scientific Laboratory containing normal uranium (added as UO/sub 2/ during the manufacture) in varying concentrations. The tensile-strength and creep data obtained are compared with the results of Los Alamos measurements upon similar materials. (auth)

A discriminator circuit for use with millimicrosecond counting equipment is described. The main characteristics of this unit are its good response to pulses as short as 3 millimicroscconds and the fast recovery time which is less than 0.15 microsec. (auth)

In the course of trying to predict the shape of NPR horizontal rod and process tube channels after several years of operation, data from 105-K were referred to. While looking at the 105-K data the following possible explanation of the ``K`` reactor distortion phenomenon occurred to me. It is written up in this document as a possible aid to those responsible for evaluating the stack distortion problem in the ``K`` reactors. Data and references to data are presented first and then an analysis of the data is presented. The author does not purport to be an expert on the ``K`` stack distortion or graphite technology but has written this analysis because it appears to be a plausible explanation of existing conditions.

The design criteria, description, flow diagrams, and some drawings of a pressurized water loop in which reactor operation conditions can be simulated are presented. The prirnary purpose of this test facility is irradiation testing of various versions of fuel elements for use in the Merchant Ship Reactor Program. The loop proper is designed for operation at 625 deg F and 2250 psi with a water flow rate of 90 gpm. Heat exchanger capacity is 150 kw at 300-F system water temperature. Loop construction is of 300 series stainless steels throughout. A by-pass purification system provides for continuous water chemistry control. Fuel pin specimens are to be irradiated in the space provided by two tubes, 1.5 II) x 24 in. long, of the "hairpin" type in positions A1 and A2 of the OHR core. The average unpertarbed neutron flux at this point in the reactor is estimated to be 5 x 10/sup 13/ thermal. (auth)

The results of an experimental investigation of heat transfer to a high velocity, vortex air flow are presented. Heat-transfer coefficients have been observed for vortex flow in tubes which are larger thaa those for linear turbulent flow at a given flow power dlssipation per unit surface area. Comparisons are drawn between air in free- and forced-vortec flow within tubes having length-to-diameter ratios of 11.7 and 20.0, respectively. and linear turbulent flow in identical tubes. For the observed range of flow power disslpation, the freevortex flow system is characterized by a heat-transfer coefficieut one to two hundred per cent larger than that calculated for linear turbuleut flow at the same pumping power. The forced-vortex flow system exhibits a superiority over linear flow only at high flow powers. (auth)

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The swelling behavior of unalloyed clad uranium operating with a cladding surface temperature of 250--350 C and fuel temperatures from 450--750 C is of importance for Hanford`s fuel element development work. To obtain information on the effect of cladding restraint, exposure, and the above temperatures, on uranium swelling rates, a series of experiments is proposed for irradiation in Hanford reactors. The experimental assemblies consist of uranium fuel rods supported concentrically in an aluminum capsule. Surrounding the fuel rod is an annulus of liquid NaK to serve as a heat transfer agent.

The information presented is an experimentally determined evaluation of standard remote handling equipment applied to the problems associated with remote maintenance of a typical reactor system component. (auth)

Weight data on the following liquid metal to air radiators is requested. This information is to be used in a comparison of the performance attainable with different nuclear reactors and liquid metal systems in a ram-jet powered airplane. The radiator dimensions are based on estimates using the performance curves presented in CNLM-338.

A nitrogen-cooled graphite-moderated nuclear reactor experiment is proposed to drive a closed-cycle gas turbine power plant at 1300 deg F. The annular core of the reactor can be rotated inside the reflector to permit fuel loading and discharge while operating at full power. Small cylindrical fuel elements of graphite are solutionimpregnated with partially enriched uranium. The fuel is recycled by incineration of the elements, chemical fresh graphite tn a small batch process. The unclad, uncoated fuel should permit high burn-up and simple fuel processing, but allows fission product diffusion into the gas stream. While methods are proposed for the removal of these from the gas, the Song-term consequences on turbine operation are unknown. The compatibility of nitrogen gas with the fuel has been studied experimentally. The radial movement of fuel gives a reactor with a constant power profile and no excess reactivity. The temperature is regulated by the fuel charging rate. (auth)

The ternary system uranium- nitrogen- carbon has been studied at 1800 deg C under vacuum and under a 1atm. nitrogen pressure. There is complete solid solubility between UN and UC, and essentially no solid solubility of nitrogen in UC/sub 2/ or U/sub 2/C/sub 3/ or of carbon in U/sub 2/N/su b 3/. At 1800 deg C the two-phase field, U(C,N) and UC/sub 2/, and the three-phase field, U(C,N), UC/ sub 2/, and C, exist in vacuum or argon. At 1 atm. of nitrogen, the uranium nitrides are more stable than the uranium carbides up to 1800 deg C, but at 2000 deg C, the uranium carbides UC/sub 2/ + U(C,N) become more stable. At 1 atm. of nitrogen, U/sub 2/N/sub 3/ is the stable phase up to 1550 deg C, and U(N,C) solid solution is stable at 1800 deg C. (auth)

The explosives group of the Chemistry Division has spent considerable time on the high explosives portion of the Woodcock program. The preliminary results obtained in the course of this investigation as well as data accumulated at other laboratories throughout the country are presented in this memorandum. Part I is concerned with the preparation and properties of the most promising `wooden` explosives (shock insensitive and high-temperature stable) explosives. Part II deals with several substitute explosives which could be used immediately in a hydrodynamic program. Part III presents a tentative schedule and indicates the role various groups at UCRL have agreed to play in the Woodcock explosives program for the next few weeks.