Figures have and can be generated that indicate a higher charge-discharge rate if required before 105-N will be comparable with existing reactors. Also, these figures show an apparent operating cost incentive to increase the charge-discharge rates proposed for 105-N. Although these figures may be true by themselves, other figures developed from the same information and stated on a basis that affords a true comparison, show that the proposed rates for 105-N are compatible with those in existing reactors. However, the accomplishments of existing reactors should be considered as a guide only and not as Criteria since the design basis has already been established for Project CAI-816. An average charge-discharge rate has been proposed for 105-N that is compatible with the two main ground rules of the Project. Namely, the capital cost limitation and the plant factor. This rate of 8 tubes/hr. is one that appears to be reasonable from the charge-discharge design aspects and there is a good possibility that it can be increased with operational experience.

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Presented at the 1958 Winter Meeting of the American Nuclear Society, December 9, 1958. Experimental and theoretical work on the selflimiting response of reactors to step and ramp insertions of reactivity is discussed along with the general characteristics of self-limiting power bursts. The static characteristics of the cores investigated are presented and the techniques of measurement are discussed. Data from step and ramp tests are presented and compared with the predictions of a theoretical formulation of reactor self- shutdown in terms of energy release. The discussion includes an evaluation of some postulated shutdown mechanisms in the light of experimental results. Some results of detailed calculations of shutdown effects due to specific mechanisms which are believed to contribute significantly to reactor self-shutdown are presented. (auth)

The national laboratory concept, laboratory objectives, the staff, research facilities. research activities, and administration are discussed in general terms and a financial statement is given. Fairly detailed accounts are given for the research programs in the fields of physics, accelerator development, instrumentation, applied mathematics, chemistry, nuclear engineering, biology, and medicine. (W.D.M.)

Given the moments of a function it is often desirable to obtain a numerical approximation of the function. A method for estimating the solutions of the Stieltjes and Hamburger moment problems is developed. Calculations indicate that the method is both feasible and accurate. (auth)

Centrifugal-casting techniques were investigated as a method of producing hollow cylindrical extrusion billets of aluminum-35 wt.% uranium. Among the variables evaluated were melt temperature, mold and pouring-spout configurations, mold speed, and method of pouring. With the equipment employed it was found that the best castings were produced utilizing a pouring temperature of 2400 ction prod- , a heavy-walled steel cylinder rotating between 700 and 900 rpm for the mold and a bottom-pouring technique employing a retractable pouring spout. Sound, nonporous billets 26 in. long and 5 in. in diameter were produced with a yield after machining of over 75% of the original charge. The major losses occurred in the pouring spout-and-cup asserably. This loss is relatively unaffected by the casting length; and, therefore, castings of greater length than 26 in. should result in even greater recoveries. (auth)

Several decisions regarding basic project philosophy must be made in order to proceed with scope design and the preparation of equipment procurement specifcations. The purpose of this document is to present as much pertinent data as possible to allow the project representatives to become familiar with the problems involved. A meeting of Representatives is planned for the near future after receipt of project authorization to discuss the scope of this project and its relationship to CG-775. Emergency flow requirements of the K reactors for planned future power levels is approximately 32,000 gpm within 68 sec. A detailed study of the existing high-pressure cross-tie line reveals that a duplicate cross-tie line and five low lift pump operation would be required to provide this flow. The existing emergency generation capacity is not adequate to supply five low lift pumps and all other necessary emergency electrical loads. A possible solution to adequate emergency flows is to connect the proposed steam turbine pump directly to the risers and to consider the turbine pump as the last ditch system. If it is determined that this does not meet the criteria of separate systems, then an alternate solution must be found.

Production of Pu from separations plants and output of unfabricated Pu exceeded commitments. Purex plant set a new record high for U processed. Production and shipments of UO{sub 3} met schedules. Purex solvent extraction battery performed below normal, probably because of poor solvent quality. NaOH addition to Redox coating removal waste is being reduced. A 3fold improvement in Recuplex product Al impurity was achieved by means of a specific gravity difference > 0.15 between dilute aqueous feed and extractant. Sintered, high-silica crucibles are being tested in RMA production line in Finished Products Operation. Scope design of a fission product shipping cask was completed; powder temperature should be below 440 F for 1 MCi cerium-144 + impurities. Feasibility of using one outside Purex canyon entrance (stairwell opening) for relief damper opening was tested and found to be insufficient. A drawing of the 6-inch continuous centrifuge being evaluated as a vacuum drum filter on RMA button line was reviewed. Casks were designed for the NPR project. (DLC)

A concentration cell electrode was installed in a fritted glass surface and was used to measure the surface KCl concentration while water was being transpired through the surface into a mixed tank of 0.1 M KCl. The results from the first Fluorox run made with crude UF/sub 4/ showed that 85.3% of the theoretical amount of UF/sub 6/ was accounted for, with 17.9% being collected in cold traps and the remainder being consumed in various side reactions. Installation was completed of apparatus to study the electrolytic removal of nickel on an engineering scale from concentrated HRT fuel solution. An extremely low yield stress of 0.02 lb/sq ft was measured for a thoria-urania slurry containing 2.5 wt.% Al/sub 2/O/sub 3/ and spherical particles of 1.7 micron mean diameter. Preliminary data on the rate of uranium sorption on Dowex 21K from sulfate solutions were correlated with a simple spherical diffusion model. Laboratory scale studies to determine the effect of reflux time, HNO/sub 3/ concentration, and air sparge on chloride removal from APPR-type Darex dissolver product showed that an air sparge is definitely beneficial in chloride removal. Preliminary cyclic cleaning tests showed that boiling 25% caustic solution was adequate for cleaning type F …

The stability of unclad zirconium hydride was investigated as a reactor moderator in carbon dioxide coolant. Two ranges of hydride were tested, an alpha- plus deltaphase hydride (ZrH/sub 0.9 plus or minus 0.2/) and a delta-phase hydride (ZrH/sub 1.5/). The delta-phase hydride exhibited excellent dimensional stability, but suffered as great as 20% hydrogen loss at 1200 deg F, together with severe corrosion. The alphaplus delta-phase hydride swelled and warped in a temperature gradient but did not lose much hydrogen and did not corrode severely even at 1200 deg F. The results indicate that zirconium hydride could not be used as unclad moderator in a carbon dioxide atmosphere in the temperature range desired for the Maritime Gas Cooled Reactor. (auth)

The toxicological properties of beryllium and compounds of beryllium are briefly reviewed, together with the historical developmert of the recommendations for maximum permissible beryllium air concentrations. The application of the enclosure technique for the control of beryllium hazards is described. Emphasis is placed on the design objectives of partial and total enclosures and the related function of auxiliary components. Monitoring procedures used to evaluate the performance of enclosures are discussed. (auth)

An evaluation of the temperature excursion and its possible consequences arising from loss of coolant from the Plutonium Recycle Test Reactor (PRTR) was made for four different postulated ruptures in the primary heavy water coolant system. As a basis for the evaluation, a series of computations was made. These were based on incremental heat and mass balances for sections of Zircaloy-clad UO/ sub 2/and Pu- Al fuel elements. Solutions to each problem defined by the postulated break size and its location were defined by finitedifference approximatioms performed by an IBM 653 machine digital computer. The four postulated ruptures were: (1) a complete parting of the 14-in.-diameter outlet pipe near the upper ring header so that coolant would be lost from both broken ends; (2) a rapture equivalent to a 14-in.-diameter hole in the primaryloop piping adjacent to the upper ring header; (1) a complete parting of a 1 3/4-in. upper jumper; and (4) a complete parting of a 1 3/4-in. bottom jumper. The Pu-Al elements represent the most critical component; melting of these elements would begin about 219 seconds after the rapture occurred if emergency backup light water coolant were not available to the system. It was found that the …

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On the basis of screening tests and favorable mechanical propenties, AISI Type 318 stainless steel was selected as a fuel-element cladding material to operate in c coolant comprised essentially of gaseous nitrogen modified by the addition of oxygen and water vapor. Tests at atmospheric pressure confirmed calculations which indicated that small additions of oxygen to nitrogen would inhibit nitriding by the process of preferential oxidation. The tests at atmospheric pressure determined that the rate of oxidation of Type 318 stainless was generally at a minimum when 0.5 volume per cent oxygen was added to the nitrogen gas. Oxidation of this steel was more severe when additions of 0.1 and 5.0 volume per cent oxygen were made to the nitrogen The rate of oxidation was primarily temperature dependent, but was also influenced by time. Oxidation during exposure periods of less than 1000 hr appeared to proceed at a parabolic rate. On longer exposures, however, there wcre indications of more rapid attack. A maximum depth of attack of 2.9 mils was observed on Type 318 stainless which had been exposed at 1650 F for 3658 hr. Stress-corrosion studies indicated that unstressed and stressed specimens were attacked at about the same rate. Stresses …

The Turco 4501 process is recommended for the decontamination of the PRFR pilot leaching plant equipment. The caustic-tartrate-nitric acid process is recommended for the decontamination of the cell and the equipment exterior. (auth)

A method for determining the concentration of Li/sup 6/ in aqueous solution was tested using the nuclear reactions Li/sup 6/(n, alpha )H and O/sup 16/(H/sup 3/,n)F/sup 18/. Annihilation gamma radiation of induced 1.87-hr F/ sup 18/ radioactivity was counted with a welltype scintillation counter, and the radioactivity per millimole of lithium was found to be independent of lithium concentration below about 0.2 moles/liter. The sensitivity limit for detecting lithium is less than 0.1 micromole (0.0075 micromole Li/sup 6/). (auth)

Preliminary experiments were conducted to evaluate the use of the nuclear reactions Li/sup 6/ (n, alpha )H/sup 3/ and O/sup 16/(H/sup 3/,n) F/sup 18/ to determine the thickness of oxide films on metals. Sheets of thin paper and of aluminum, imbedded in powdered LiF, were irradiated with pile neutrons at a flux of 6 x 10/sup 11/ n/cm/sup 2//sec and counted with an end-window proportional counter. A saturation activity of 1.87 hr F/sup 18/ of 150 dis/min per microgram of oxygen was observed in the paper, but radioactivity due to impurities masked F/sup 18/ in the aluminum. It is concluded that a 1 A (0.01 mu gm/cm/sup 2/) oxide film thickness may be measured by a neutron irradiation at a flux of 10/sup 14/ n/cm/sup 2//sec but chemical separation of induced radioactivity from the bulk metal is essential. (auth)

The nil-ductility-transitaion (NDT) temperature, as defined by the Naval Research Laboratory drop-weight test, was determined on the A212B carbon-silicon steel used in the pressure vessel of the N. S. Savannah reactor. Correlations were made with the Charpy-V-notch impact energy at NDT. Specimens taken at two different thickness locations from material used in the ipper closure head of the reactor vessel yielded NDT temperatures of 0 to 20 deg F which correspond to Charpy-V-notch impact energies of 11 to 19 ft-lb. Testing of as-received material used in the lower closure head indicated that the NDT temperature was 50 deg F which was equivalent to an average CharpyV-notch impact energy of 12 ft-lb. After normalizing and stress-relieving thin material, in order to more closely approximate the final ccndition of the reactor vessel, NDT was reduced to less than 10 deg F. (auth)

Progress is reponted on lifetime tests of rotors and determination of power loss of the scoop system. (T.R.H.)

In research in support of the GCRE, procedures for the fabrication of stainless steel-clad flat-plate fuel elements having a core of 28 w/o UN dispersed in an iron-18 w/o chromium--14 w/o nickel--2.5 w/o molybdenum matrix were developed. The preparation of UN and its compatibility with the components of the matrix alloy were studied. The UN for the program was prepared by nitriding uranium metal at 850 C and then dissociating the U/sub 2/N/sub 3/ produced to UN in a vacuum at 1300 C. In compatibility studies, UN reacted with nickel alone at 1800 F, but no reaction with nickel was observed when the other matrix components were also present. The effects of fabricational variables were evaluated by metallographic examination, longitudinal and transverse tensile tests, bend tests, and corrosion tests. Studies indicated that minus 200 plus 325-mesh UN dispersed in a minus 325-mesh elemental-powder matrix rolled green vith a 30 per cent initial reduction at 2100 F and then annealed 3 hr at 2300 F produced the best fuel core. (auth)

Techniques involving the use of high-intensity short-duration light pulses have been applied t o the study of the kinetics of photoconductivity in films of metal-free phthalocyanine. These experiments, in conjunction with measurements of steady-state photoconductivity, are consistent with the following scheme. The principal route for the formation of charge carriers is via the first excited singlet state, although the lowest triplet state can, t o some extent, contribute to charge - carrier production. The mobility of the carriers is low and is concentration-dependent, being lower at higher carrier concentration. The decay of the photocurrent is the result of a diffusion-limited bimolecular recombination, with a capture radius of approximately one molecular diameter. The experiments indicate that carriers produced thermally in the dark do not interact with light-produced carriers.

The addition of ortho-chloranil to the surface of films of metal-free phthalocyanine has been found (a) to increase the dark conductivity of such films by as much as 10{sup 7}, (b) to increase the steady-state photoconductivity by as much as 10{sup 5}, and (c) to result in the formation of unpaired electrons whose concentration decreases reversibly as a result of illumination. These systems exhibit a light-induced polarization, the phthalocyanine layer becoming more positive with respect t o the ortho-chloranil layer. Kinetic studies demonstrate that, upon illumination, a single process (time constant = 40 seconds) results in the increase in conductivity, the decrease in unpaired spins, and the increase in polarization. The results are consistent with the following scheme. An electron transfer from phthalocyanine to ortho-chloranil occurs in the dark at room temperature, producing holes in the phthalocyanine layer and ortho-chloranil negative ion radicals (high conductivity, ESR signal). Illumination results in the transfer of an electron from an excited phthalocyanine molecule to the ortho-chloranil negative ion, producing further phthalocyanine holes and ortho-chloranil double-negative ion (increase in conductivity, increase in polarization, decrease in ESR signal). By equating spin concentration with charge - carrier concentration (phthalocyanine holes) it is possible to calculate a …

Electron microscopy was used to supplement metallographic studies of bonds between Zircaloy-2 interfaces. Treated surfaces before bonding, and bonded sections made by a variety of techniques were examined. Electron micrographs of belt-abraded surfaces exhibited a consistent fine-scale roughness. Chemically pickled surfaces were nearly smooth regardless of prior treatment. Chemically pickled samples and a zirconium oxide-coated sample pressure bonded at 1500 F and 10,000 psi had pitting at bond lines that could have been due to voids or to contaminant at the interface which etchod out. The pitting was almost completely eliminated in one sample by pressing one hour at 500 F and 350,000 psi. This indicated that the bond-line pitting in these samples was due to voids at the interface. Zircaloy-2 samples pressure bonded after coating with carbon chromium, iron nickel, or tin etched in relief along the bond line, indicating the presence of contaminant at the interface. On the basis of the present investigation, it is proposed that grain growth across the interface in chemically pickled samples may have been inhibited by the presence of a thin contaminant film originally present on the Zircaloy surfaces. However, the poor grain-growth characteristics of chemically pickled samples may also be due in …

Detailed consideration is given to some properties of the first excited electronic state. Following the analysis proposed by Mulliken, SCF LCAO-MO coefficients are used to obtain qualitative information about the electron distribution. Comparison is made with earlier work with respect to the description of the excited state in terms of the interacting configurations. In addition to the excited-state dipole moment, the effective electric moment between the ground and excited states is also calculated. From this, the oscillator strength for the first allowed transition is computed as a function of the internuclear distance. (auth)