Progress report of the Oak Ridge National Laboratory Metallurgy Division providing updates on various projects, experiments, and other work. This report includes a summary of nondestructive testing, physical chemistry of corrosion, fundamental physico-metallurgical research, HRP metallurgy, process metallurgy, metallurgical materials and processing, metallography, and ceramics research.

Continued work on the adsorbability of metal complexes from concentrated LiCl solutions and LiCl-HCl mixtures on a strong-base anion-exchange resin further demonstrated the much higher adsorbability of these complexes from LiCl solutions than from HCl solutions. The effect is believed to be due to the formation of less strongly adsorbed undissociated chloro-complex acids in the case of the HCl solutions.

The ORNL 86-in. cyclotron is being modified to provide for deflection of the proton beam. It is expected that operation will be resumed late in the spring. Nuclear physics work was limited, for the most part, to interpretation of previously collected data and to making preparations for utilizing the deflected beam. It was found that for certain isotopes the production rates could be almost doubled by operating at a slightly reduced energy and a much larger current. With the use of the ORNL 63-in. cyclotron, the absolute values of the electron capture and loss cross sections for 26-Mev nitrogen ions were obtained. The angular distribution of the cross sections for elastic scattering of nitrogen by nitrogen was measured at energies from 13 to 22 Mev. A double-focusing 90-deg magnet is being planned for use in identifying stable reaction products from nitrogen-induced reactions. The major components of the revised 44-in. test cyclotron were assembled and are being tested. Consideration is being given to the use of these components, along with a new 20,000-oersted magnet and a shielded cyclotron room, and if the tests are satisfactory the Laboratory will have available a machine which will accelerate N5+ ions to 81 Mev.

Changes made in the Thorex process flowsheet were a decrease in the extraction column acidity to decrease thorium losses and the addition of a second thorium solvent-extraction cycle to provide the increased decontamination required when thorium irradiated to 2000-4000 g of U233 per ton is processed. Bonded slugs could not be dissolved by the Thorex flowsheet procedure. Various laboratory scale studies on feed preparation, first-cycle variables, and radiation damage to the solvent are reported.

This quarterly progress report of the Aircraft Nuclear Propulsion Project at ORNL records the technical progress of the research on circulating-fuel reactors and ether ANP research at the Laboratory under its Contract W-7405-eng-26. The report is divided into three major parts: I. Reactor Theory, Component Development, and Construction, II. Materials Research, and III. Shielding Research.

In some recent experiments the ion density in a plasma was measured as a function of radial distance from a d-c arc source of ions for the magnetic field intensities from 2500 to 14000 oersted. The diffusion coefficient appeared to very inversely as the square of the magnetic field strength, D~1/H2. The absolute value of D was shown to be approximately that which would be predicted by the collision diffusion theory when account is taken of the shorting effect of the end walls. The purpose of this report is to continue the examination of ion diffusion in a plasma and field experimentally the relation between the diffusion coefficient and the neutral gas pressure for a constant magnetic field.

The general Wigner-Eisenbud theory is used to develop a method of analysis for the cross sections of fissionable nuclei. The method is employed in giving a reasonable description of the low energy cross sections in U/sup 235/. The single level fit for U/sup 235/ is known to be unreasonable. Many level expressions for the cross sections are derived--the only approximation to the general theory being the neglect of all but a small group of resonances. It is shown that regardless of the number or definition of the fission channels the many-level expressions require few level parameters: the E/sub lambda /, GAMMA / sub lambda n/, GAMMA /sub lambda gamma / and GAMMA /sub lambda F/ of the single level theory for each resonance and a few additional parameters pertinent to the interference between levels. The interference terms are described and shown to be important. The shape and size of the U/sup 235/ cross sections below 2 ev are fitied to within one per cent using (a) only one negative energy resonance of smaller size than in the single level fits (b) no additional levels to fit the shape other than the observed levels at positive energies (c) three interference parameters …

Measurements of flow rate through the fuel high-pressure system sampler indicate that the average flow rates is about 0.29 gpm (145 lb/hr) plus or minus 50%, which affords an adequate purge of from 12 to 36 volumes through the sample line if the full fifteen minutes of purging is allowed before isolating the sample. The fuel sample cooler was fund to have adequate capacity to reduce the temperature of the fuel solution form about 275 to 70 C, using pre-heated cooling water at 70 C. Uncertainties in temperature measurements make it impossible to estimate an observed over-all heat transfer coefficient.

An estimate has been obtained of the heat that should be generated in the HRT core in order to hold the system at operating temperature under no-load conditions. This estimate was made by measuring the feed-water rate to the package boiler during an oxygenated water rung. Results are summarized.

The expected performance of the HRT carbon beds was calculated for various reactor operating conditions. the calculations indicated that the flow rate of sweep gas will have to be limited to prevent excessive activity discharge. Data on activity discharge are included.

During the pre-startup phase of the HRT operations, moisture was accidentally introduced into the charcoal bed adsorbers in the off-gas system. Tests have been made to determine the effect of wetting upon the adsorptive properties of the charcoal. The work was divided into two phases, testing of fresh charcoal in the laboratory and testing of the HRT charcoal beds in situ. It is recommended that the beds be dried by heating them to about 40 C and purging each with one to two liters/min of dry instrument air.

A 10% phosphoric acid solution contain 0.2% "Rodine 45" inhibitor is recommended to be used for the chemical cleaning of the HRT seam and closed colling water systems. Wet storage is recommended for both of these systems. The steam system is to be stored with steam condensate containing 100 ppm hydrazine, and closed cooling water system is to be stored with steam condensate containing 1000 ppm potassium chromate.

To supply information about the several letdown valves which have been in HRT service, a typical valve plug examined by the Metallurgy Section confirms the belief that chemical attack on the Stellite #6 was occurring. It appears that most of the corrosion was due to rinse solutions, since this phenomenon has not been noted on letdown valves in the HRT Mockup where over 90% of the operating time has been with UO2SO4 solutions.

The Eyewash program, written by James H. Alexander and Nancy D. Given, provides solutions of reactor criticality problems in spherical geometry by means of the group diffusion method. It employs thirty lethargy groups (plus one thermal group) in nine regions. The input consists principally of specifying the geometrical scaling factor, boundaries and compositions of the various regions, and temperature level. The output includes the value of vc that would render the system critical, the relative fission density distribution, fissions, absorptions, and leakages in each lethargy group in each region, and, if desired, an edit of the flux at each space point, each lethargy, and an edit of the macroscopic cross sections for each lethargy, each region. OCUSOL-A is a minor modification and extension of Eyewash. It provides for the computation and editing, on the supervisory control typewriter, of the total absorptions in selected nuclides in the various regions. This information is useful in the computation of breeding ratios and the preparation of detailed neutron balances, and in the estimation of flux-averaged cross sections for use in estimating the rate of change of concentration of the various nuclides with burn-up. The program also provides for saving and transferring the final fission …

Radiation level measurements of various HRE fuel system components, made in September, 1956, after 27 moths of storage, are compared with the June, 1954, readings before storage. Measurements were made with a standard cutie pie and results tabulated.

Specifications are presented for cleanliness during installation of piping and equipment in the High Level Volatility Laboratory, Bldg. 4507.

Design calculations were made for a system consisting of a pump, one hundred feet of pipe, and a heat exchanger to remove 1 Mw of heat from various aqueous thorium oxide slurries. The rheological properties of the slurries were varied over a range of yield stresses from 0 to 1.5 lb/sq ft and of coefficients of rigidity from 1/2 to 2 centipoise. Two different cases were studied: a heat exchanger having fixed axial and radial delta T in which the tube length was allowed to vary and a heat exchanger having fixed tube length in which the axial and radial delta T were allowed to vary. It was shown that the pump power must be increased by a factor of 15 to 30 in order to maintain satisfactory operation of the heat exchanger as the slurry yield stress is increased form 0 to 1.5 lb/sq ft. However the pump power is essentially independent of heat exchanger tube diameter for any given slurry. The rated capacity of a slurry heat exchange is essentially independent of slurry yield stress and coefficient of rigidity, provided that the tube velocity can be suitably increased as the slurry yield stress in increased.

The OCUSOL-A program (ORNL-CF-57-6-4) for Univac is a modification of the Eyewash (ORNL-1925) multi-group, multi-region reactor code. The group=energy-lethargy-temperature relationship are given in Table A. The element code numbers are given in Table B. The cross sections now on the sigma-tape are given in tables in the Appendix numbered with the element code number. This technical report explains the bases for choosing the cross sections.

An investigation of the causes of observed explosive reaction of zirconium-coated uranium dioxide on dissolution in nitric acid was conducted. It was concluded that such a reaction is to be expected. Possible but unconfirmed methods of alleviating the problem are suggested.

For various reasons it is not possible to leave the uranium or other nuclear fuel in a power reactor until all of it has been "burned up" by fission. In the case of liquid fuel (homogeneous) reactors a small part is continuously bled out, purified and returned. In the case of solid fuel reactors, fuel elements are periodically removed, reprocessed and the "unburned" fuel put back into service. In both cases the purification produces wastes which contain radioactive fission products and transuranic elements, and it is with the disposal of these wastes that we are concerned. For technical reasons, we will limit our consideration to the wastes from the processing of solid fuel elements, and from the processing of the very similar solid "blanket" elements in which fissionable fuel is made from non-fissionable isotopes of uranium and thorium by interaction with neutrons in the outer regions of the nuclear reactor.

A slurry addition system, a venturi in the circulation loop, and two types of sampling systems were tested with 500 and 800 g Th/kg H2O slurries in the 200 gpm loop at 250 C and 1000 psig. The addition system worked satisfactorily while the venturi gave erratic readings during part of the run. Both the capillary and in-line sampling systems proved satisfactory with the capillary sampler being much easier and more convenient to operate. The addition of uranium to the slurry had no appreciable effect on the handling characteristics, the attack rate on 347 SS, the particle size and crystallite size of the thorium oxide. The attack rate was found to be 1 mpy during the first 100 hours of circulation and decreased to 0.4 mpy at the end of the run.

This technical report summarizes some preliminary calculations of fuel exposures attainable in heterogeneous reactors, fueled with a mixture of thorium and U233, moderated with D2O and operated with no net loss in fissionable fuel.

Loop L-2-10 was the eighth completed in-pile loop experiment and the first in the HB-2 beam hole at the LITR. The loop was inserted on July 2, 1956 and removed on September 3, 1956. The installation, operation, removal, and general performance of the HRP in-pile solution corrosion loop in the HB-2 beam hole at the LITR are described.

A spectrophotometric method for the determination of cerium with Tiron (disodium-1,2-dihydroxybenzene-3,5disulfonate) was applied to the determination of cerium in samples which contain uranium and zirconium. The cerium-Tiron complex in solutions of pH 8 or greater exhibits an absorption maximum of 500 mu . This reagent does not react with any other lanthanide element. The interference of iron, uranium, and zirconium was eliminated by extracting these interfering elements with a solution of trioctylphosphine oxide in cyclohexane. (auth)