The Experimental Power Breeder Reactor (EBR-II) is a heterogeneous, unmoderated, Na-cooled reactor developed to provide engineering and operational information on fullscale central-station power plants. The enriched U-fissium alloy fuel is blanketed with depleted unalloyed U in type 304 stainless steel tubes. Details of fabrication and loading of these rods are given. (J.R.D.)

Progress is reported on the following studies: the possible relationship between environmental Ra/sup 226/ and incidence of bone tumors in human populations; the incidence of tumors in mice exposed to chronic gamma irradiation; the effects of chronic gamma irradiation on histology of testes cells; the effects of periodic exposure to gamma radiation on the mortality of guinea pigs; determinations of the density of various mouse tissues; the synthesis of dimethyl formarmide (DMF) and uranyl nitrate-DMF; an investigation of the role of the small intestine in acute radiation death in mice following exposure to fast neutrons or gamma radiation; the effect of neutron dose on the incidence of mammary tumors and fertility of female rats and mice; measurements of Cs/sup 137/ in samples of tea and human milk made with a gamma spectrometer; the latency and growth of bone tumors induced by injected Sr/sup 90/ in two strains of mice; histopathologic changes in the skeleton of mice following injection of various doses of Ra/sup 226/ the development of mathematical models of cellular populations; reaction mechanisms in the response of chicks to radiation injuries; cell generation times in E. coli; the demonstration of infective organisms living in the cytoplasm of A. proteus; …

The chemical problems largely involve gas- and solidphase chemistry where chemical reactions and physicochemical processes occur at elevated temperatures ( approximately 4000 deg F). The high temperatures require that the fuel bodies and moderator be made of refractory materials and may preclude the use of metal cladding. Areas of concern include reactor materials and primary coolant systems, where most of the problems involve mass transfer. Reactions are discussed which can lead to carbon transfer in a gas-cooled graphite reactor. Substantial mass transfer can be expected from gas-phase diffusion across a gap caused by equilibrium concentration shifts when the gap boundaries are at different temperatures. Reactions are discussed which show how coolant impurities can lead to fuel migration. Activated charcoal appears to be a most useful agent for removing volatile-fission-product activities from-the reactor coolant. In regard to the minimization of hightemperature vaporization processes, the carbide-- graphite systems appear better than the oxide systems because the fuel material carbides are less volatile than the oxides in the presence of graphite. The vapor pressures are tabulated for gas-cooled-reactor fuel materials. (B.O.G.)

"The grafting of methacrylic acid, styrene (2: 1 mole ratio) co-monomer mixture on polypropylene film and fabric, was studied to compare electron accelerators and isotopes as sources of radiation. An aluminum block that contalns i/8-in.-deep pockets covered with Mylar film for holding sample and monomer during mutual irradiatlon was developed. A preliminary comparison was made in post grafting polypropylene film and fabric preirradiated with Cow and with an electron accelerator source. It was found that post grafting was rapid at 80 ts C but slow at room temperature. Monomer equilibration before irradiation increased the grafting rate. Higher grafts were obtained when samples were irradiated in sparged and sealed containers. The grafting rate increased as dose rate decreased."

>A study was made of the energy levels of Pu/sup 238/ which are populated by Np/sup 238/ beta decay, by an examination of the Np/sup 238/ conversion electron spectrum in high-resolution beta spectrographs. The general features of the level scheme as previously given were unchanged but several new transitions were observed, with energies of 119.8, 871, 943, 989, and 1034 kev. Two new levels are postulated at 915 and 1034 kev which accommodate all but the 943-kev transition. A possible assignment of the 943-kev transition to the (0+.0) state of the beta vibrational band is discussed. In addition, the weak 885-kev transition from the 2+ state of the gamma -vibrational band to the 4+ state of the ground band was seen and its relative intensity determined. Comparisons were made of the experimental relative transition intensities of the three photons depopulating this band with those predicted from the rules of Alaga et al.; only fair agreement was noted. A discussion is given of the beta decay branchings and log ft values of Np/sup 238/ decay in terms of the postulated characters of the Pu/sup 238/ states and the measured spin of Np/sup 238/. (auth)

A preliminary design enabling the downward transport of solids in multistage fluidization reactors is discussed, and a program to improve the preliminary plate design is reported. A three-stage 6-in. dia. column was constructed to obtain and correlate design and mass-transfer data. The preliminary plate design was improved by incorporation of a cover screen as a part of each plate which sandwiched the large nonfluidized beads, resulting in improved stability, and the use of internal vibration which permitted control of the fluidized solids bed depth on an individual stage basis. All of the design data were correlated into a set of five equations. From the equations it is possible to calculate the amount and size of nonfluidized beads that are necessary to achieve a given throughput rate of any material under any operating conditions. The experimental work is reported in the areas of development of a design correlation using a glass bead-air system, and investigation of coluum efficiency from mass-transfer runs involving the adsorption of water vapor from air by silica gel. (J.R.D.)

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A Po/sup 210/ source was used to furnish a reliab1e ground for both electron and positron sources. This was done to prevent the electron and positron sources from charging during BETA spectral studies in magnetic lens spectrometers. An approximately 20- mu c Po/sup 210/ source was placed 1.2 in. behind a 4- mu c Na/sup 2 / 2>s positron emitter backed by 20- mu g/cm/sup 2/ Formvar in the spectrometer; this arrangement resulted in a charging rate decrease of approximately 80%. When the source was placed 0.5 in. away, no charging was detectable over a period of more than one week. The discharge is attributed mainly to the loss of electrons from the source and backing caused by ionization of alpha particles since few alpha particles are stopped near the source. (B.O.G.)

This monthly report details activities of the Hanford Operations Office during the month of December 1960. (FI)

The results of preliminary design and evaluation studies of various concepts of a power reactor that is moderated by heavy water and fueled with natural uranium are presented. Twenty-nine conceptal designs were developed for reactors ranging in capacity from 100 Mwe to 460 Mwe. Resigns were prepared for hot- and cold-moderator reac tors of the pressure vessel type, with liquid D/sub 2/O, boiling D/sub 2/O, E/sub 2/O steam, and helium as coolants. Also studied were cold-moderator pressure tube reactors cooled with liquid D/sub 2/O and boiling D/sub 2/O. The repont includes the results of engineering studies of the reactor systems, electrical generation facilities, and auxiliary equipment. (auth)

A helium coolant purification system was designed for the proposed 800 Mwt Pebble Bed Reactor. The purification system will operate on a coolant side steam with a flow rate 1% of the total coolant flow, and there are provisions for radioactive and nonradioactive contamination removal. Primary equipment components are dual oxidizers, an economizer heat exchanger, a gas cooler, dual absorbers, a fission-product gas-delay trap, and dual filters. The fission- product trap is sized to provide a hold-up of 30 min for krypton and 6 hr for xenon and for 99.9% retention of iodine. Nonradioactive decontamination is sufficient to maintain oxygen bearing contamination at < 30 ppm in the coolant. Total cost of the system excluding auxiliary equipment and containment was estimated to be 6,360. (auth)

The results of instability studies suggest that the operational characteristics of the fully ribbed and rigid Mark III loading are governed by feedback processes that guarantee safe and stable operation under normal operating condiiions. No evidence of positive reactivity effects was noted for the fully-ribbed rigid core. Logical extrapolations of full-power full-flow test data indicate that the reactor could be brought into a resonant condition for power levels exceeding 1000 Mw. Strong nonlinearities were observed in power coefficients and were considered to pose no serious operational problems above 200 kw in the power range associated with the tests. An application of the Nyquist stability criterion to the extrapolated fully sheared data results in the conclusion that the reactor would attain resonance instability at full flow at - 11 Mw. Logical extrapolations of test data for one-third flow results in resonance instability at -10 Mw, a power level -20 times that designed for onethird flow. Rib shearing was shown to result in an unexpected and unexplained increase in the magnitude of the delayed structural power coefficient component. An empirical fit of feedback data to a model describing the dynamic and static behavior of the partially sheared core resulted in ihe values …

A brief review of the theoretical water-boiler reactor-power transfer function is presented as background for the experimental determination of the ratio of effective prompt neutron lifetime to the effective fraction of delayed neutrons, 1/beta. The preparation and performance ot the experiment are discussed with special emphasis on equipment procedures, and measurement errors. The results, which strongly support a seven-delay-group model of the reactor, are presented and compared with theoretical six-and seven-group models. The experiment indicates qualitative values of the seventh-group constants, and it also indicates an 1/beta = 7.7 plus or minus 0.3 msec valid for all but short- period transients. (auth)

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A concept of a nuclear power plant to be assembled on earth and operated on the moon is presented. The two principal design objectives are reliability and high specific power. Wherever there is an incompatibility between these two objectives, the decision favors reliability. The design is based on the premise that the power plant must be designed on the basis of current technology and with a minimum amount of research and development. The principal components consist of a fast reactor in a direct cycle with a mercury-vapor turbine. The high- frequency generator, hydrogen compressor for the generator cooling system, mercury-recirculating pump, and condensate pump are on an extension of the turbine shaft. Ths mercury vapor is condensed and the hydrogen cooled in wing radiators. The reactor is of a construction quite similar to EBR-I Mark IlI for which there is a large amount of operating experience. The radiator is a vertical tube-and-fin type built in concentric cylindrical sections of increseing diameter. The curved headers are connected by swivel joints so that, upon arrival, the radiator can be quickly unfolded from the compact cylindrical package it formed during transportation. (auth)

In a program directed toward the optimization of the process chemistry of the STR hydrofluoric acid method of reprocessing zirconium-uranium alloy fuels, it was shown that the process can be modified to dissolve homogeneously fuels of higher uranium content by either hydrogen peroxide oxidation or dilution of the dissolver solution. Rate of corrosion of Monel was acceptable with both methods of dissolution. Phase and stability studies of the solvent extraction feed and waste solutions indicated that higher concentrations of zirconium and uranium could be used in the process streams. Metastable solutions were obtained when the currently used STR raffinate solutions were evaporated. This operation was not favored for flowsheet use. The batch and continuous dissolution and solvent extraction flowsheets are given embodying the principal results of this study. (auth)

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No abstract.<><DSN>15:017244<ABS>Discussions are presented of the metallurgical properties and fabrication processes for molybdenum and its alloys of titanium, tungsten, and zirconium. (B.O.G.)

A decision was made to begin fabrication for the initial core loading of LAMPRE-1 with capsules from the tantalum on hand. Fuel for the first loading will be the cast Fe--Pu alloy from LCX III capsules and will contain carbon and stabilizer. Certification and melt-freeze tests are continuing on LAMPRE type capsules. The filling of the reactor sodium system is described. The cover gas system operated satisfactorily during the sodium shakedown phase. Four of the 15 core thermocouples have operated improperly since the sodium system was filled. The capsule charges were operated to remove dummy capsules and insert tantalum capsules containing test coupons. The 2000-kw Sodium Test Facility, including test steam generator, was operated continuously from Aug. 20 to Nov. 20, except for l59 hr of shutdown required for maintenance of auxiliary steam system equipment. Mercury-water flow systems were set up and are being operated to study both lift and jet pumping. A second fuel pumping experiment using Co --Ce - -Pu fuel was set up and tried without success. The effects of various additives on the properties of Fe-Pu fuels are being studied. The fabrication of LAMPRE-1 capsules by impact-extruding a rod-slug into a starting cup followed by six …

System Design. A chem-milled outer skin, an improved thermoelectric element adjustment and access plug, a flexible stainless steel-aluminum joint welded via ultrasoric techniques, a flexible hot shoe assembly, and thermal hydrauilc heat dump system were incorporated into the design of the environmental and ground test generators. Materials Analysis. Burnup studies on fuel forms were continued with CeF/sub 3/ and CeO/sub 2/. SiC/sub 2/ appeared to be the most promising addition to CeO/sub 2/. Tests showed that the Allegheny Ludlum alloy S-818 alloy is resistant to attack by CeO/sub 2/ and CeF/sub 3/, but is attacked by Ce metal. Hazards Analysis Analyses of launch abort impact zones for the open core and of aerodynamic burnup for near orbital injection on two types of Mo fuel cores continued. Manufacturing. Fabrication and assembly of the first electrically heated generator was completed. System and Component Test. It was found that lead telluride couples increased in resistivitg after heating to l000 deg F and masked resistivity changes because of radiation. Inconel X cores were heated to approximately 15O0 deg and impacted on either granite or water tatgets. All of thr cerium-metal loaded cores ruptured. Cores loaded with lavite pellets were recovered intact. Heat transfer mockup …

Critical mass, spectrum, breeding ratio, and coolant removal coefficients were calculated for a series of large Pu- U/sup 238/-fueled sodium- cooled fast-breeder power reactors, using a new 16-group cross-section set based in pant on recent miscroscopic cross-section measurements. The parameters studied include reactor size, plutonium isotopic content, and type of structural material. Reactors cooled with Pb - Bi eutectic and those contaiing U/sup 233/- Th fuel were examined. (auath)

Specifications for the fuel assemblies Experimental Gas Cooled Reactor (EGCR) Core-I were developed for use in procuring the first core loading. A fuel assembly for the EGCR consists of a cluster of seven cylindrical fuel elements spaced and supported within a graphite sleeve. Each fuel element consists of a stainless-steel tube containing a column of hollow UO/sub 2/ pellets and having a spacer brazed at the midsection to control the spacing between fuel elements in a cluster. A master specification for the fuel assembly, a supplementary specification for each of the components, and a specification on record keeping daring manufacture are included. (auth)

The absorption spectra of Np(IV), Np(V), and Np(VI) were measured in 1M HNO/sub 3/ and a spectrophotometric method of analysis was devised for mixtures of Np(IV) and Np(V) in nitric acid solution. In the analysis, the absorption of Np(IV) was measured at the sharp absorption band at about 715 m mu and the absorption of Np(V) was measured at 617 m mu . A novel adaptation of a Beckman DU spectrophotometer permitted the neptunium solutions to be confined in a gloved box so that the instrument was not exposed to possible contamination by the alpha activity of Np/sup 237/. (auth)

Tests were carried out to determine the action of a static sodium environment on a special high-temperature ball bearing while operating at the specified speed and loading. The test bearing was operated at 85 rpm and 870 pounds axial load for 385 hr at 1000 deg F. Visual inspection of the test bearing showed a very marked increase in roughness of both the balls and the ball races. Details of the measurements and a photograph of the bearing parts after test are given. On the basis of this test it did not appear that this bearing will be satisfactory for the service intended. (M.C.G.)