The radiolytic decomposition of tributyl phosphate has been show by burr to product gases, acids, and polymers. the acids that are formed can limit the usefulness of tributyl phosphate for the processing of radioactive materials. The study of acid formation on radiolysis therefor becomes important to us for the understanding of the mechanism of acid formation, the influence of added materials and the effect of the structure of organo- phosphorous compounds. Samples of purified esters have been irradiated in the ORNL cobalt source. Conclusions: (1) The formation of acid from tributyl phosphate during irradiation with cobalt gamma rays involves a mechanism that is not a primary step. Evidence has been obtained for a secondary reaction that is minimized by the presence of certain compounds. (2) Toluene acting as an inhibitor for radiolytic formation of acid may indicate the usefulness of an aromatic hydrocarbon diluent in processing. (3) The aromatic hydrocarbon, when phenyl, was not effective when it was part of the molecule. (4) First tests revealed that dibutyl butyl-phosphonate produced less acid the TBP and may warrant further consideration for process application.

The method is based on caustic precipitation and centrifugation (which removes the Cs and small amounts of Sr, rare earths, Zr, Nb, and Ru). These are removed in the supernatant and run through a cation exchange column. This separates Zr-NB and Ru. The effluent is precipitated and the Zr-Nb is stored in an asphalt pit. The Ru then may be recovered from the precipitate. The precipitate from the original centrifugation is calcined, pressed and transported to a deep well.

In an elastic collision the neutron loses part of its kinetic energy to the nucleus with both the kinetic and momentum of the system being conserved. However, for many elements the scattering is not isotropic in the center-of-mass system at the higher neutron energies. Many of the present reactor multigroup codes include anisotropic scattering at the high neutron energies, while many others assume isotropic scattering at all energies. In order to consider some of the effects of including anisotropic scatting, reference is made t the multigroup equation generally assumed for the slowing-down density.

This semi-annual report of the Applied Health Physics Section of the Health Physics Division provides both narrative and quantitative descriptions of area air monitoring activities, fallout activity, rain water analyses, Clinch River and White Oak Creek analyses, background radiation monitoring, and monitoring of the work and protective garments laundry. Measurements for gamma and beta activity are reported in millicuries/cubic centimeter. The report does not provide information on specific radionuclides.

In order to evaluate the behavior of an APPR type absorber rod, an irradiation test program has been established. Approximately 21 more samples are planned for testing under this request. The request proposes testing a full size APPR-1 type control rod in the MTR. The objective of the test is to better evaluate the neutron absorbing material proposed for the APPR-1 control rod.

The failure of the valve bellows would appear to be due to a combination of stress corrosion and crevice corrosion. Stress corrosion occurred as evidenced by the transgranular branched cracking found in the bellows and in the base which which was joined to the bellows. It seems probable that chlorides were present, which, along with the residual stresses present in the bellows assembly, created the necessary conditions for stress corrosion to occur. Crevice corrosion occurred probably due to heavy deposits of solids at the base of the bellows, which created a condition of oxygen impoverishment. While the crater in the base may have been related to a galvanic effect created by the gold gasket, the contour of the crater would suggest that the cause of the crater was due more to crevice corrosion.

The information concerning beryllium assembled herein has been selected primarily to provide information that might be pertinent to the design of the ART. The creep-rupture data in the literature have been obtained from vacuum cast and extruded beryllium, rather than from the hot-pressed beryllium which will be used in the ART. A research program is being conducted by the Brush Beryllium Company, under contract to the Oak Ridge National Laboratory, which will eventually provide the design engineers with data on the high temperature strength properties of hot-pressed beryllium. In the interim, it will be necessary for the metallurgists and design engineers to make judicious estimates and extrapolations from the data available.

The fact that material transport does occur under conditions of finite temperature difference in a flowing molten metal system was established. The rate mass transfer was thought to be either diffusion limited or solution rate limited. It is believed that the mass transfer of structural materials in Na or NaK systems is solution rate limited. The limiting process has not been qualitatively or quantitatively confirmed for the Inconel-Na or Inconel-NaK system. Increasing the maximum system wall temperature increases the amount of mass transfer, at least above 1300 deg F. The effect of the total temperature difference across the system on the amount of mass transfer was determined.

A method was developed for calculating shield induced gamma radiation escaping through openings in a biological shield. The method was applied to the HRT and the results indicated that the contribution to the dose from induced activity in the HRT shield was around 0.1 r/hr and was insignificant in comparison to to other mechanisms contributing to the escape of gamma rays through shield openings.

A simplified method was developed for calculating wall-scatter gamma radiation escaping through a shield opening. The method was applied to the HRT and the results showed that next to the line of sight contribution, scattering of the wall of the shield opening was the main contribution to the dose at the rear edge of the shield. Design charts were prepared that give the dose as a function of the gamma source location with the reactor cell.

The HRT leak detector system consists of four headers each of which are connected on one side to a common supply of pressurized water and on the other side by individual tubing to the ring grooves of approximately twenty flanges. There are two methods of detecting the loss of water that are particularly applicable to the HRT: (1) By the loss of pressure in a constant volume system; (2) By the measurement of flow from a constant pressure system. It was determined to investigate the second method which requires a flowmeter capable of measuring flows of .5 cc or less of water per hour. The experiment flowmeter constructed performed almost exactly as the design calculations predicted.

Resistance of carbon steel to corrosion in oxygenated high-temperature (250C) water was unexpectedly good at high oxygen concentration. Pertinent literature, critically examined, and toroid experiments indicted that at low oxygen concentration attack did increase with concentration, but as oxygen concentration was sufficiently increased, more protective films were formed on the metal. Some corrosion factors in the application of carbon steel to nuclear reactors systems are discussed.

Catalysts for use in recombining the gases produced by the radiolytic decomposition of water in thorium oxide slurries under neutron irradiation were investigated in out-of-pile tests using stoichiometric mixtures of hydrogen and oxygen. Most favorable results were obtained with a molybdenum oxide catalyst. Satisfactory rate also were attained with palladium and silver oxides. Copper, nickel, vanadium and chromium compounds were less effective.

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.

A promising scheme for the chemical processing of a thorium breeder reactor of the two-region aqueous homogeneous type consists of the following operations: concentration of insoluble fission and corrosion products from the core system into a small volume of fuel solution, combining this slurry with irradiated thorium oxide slurry taken from the blanket, recovery of D2O by evaporation, dissolution of the thorium and uranium in HNO3, and, after a suitable cooling period, recovery of the uranium and thorium by solvent extraction for return to the reactor. The use of a hydroclone and underflow container arrangement for concentrating insoluble fission and corrosion products under simulated reactor conditions has been successfully demonstrated on dynamic loops. Solids concentration factors greater than 103 were demonstrated, and equilibrium solids concentration in the circulating solution less than 1 ppm was attained in these tests. Present data indicate that proper design and operation will minimize solids deposition in the reactor system and that the insoluble impurities can be effectively removed by the hydroclone. An alternate method of processing the slurry removed from the core system by the hydroclone consists of removing the room temperature insolubles by centrifugation, recovering the uranium from the supernatant by peroxide precipitation, thermal …

A qualitative theory for cake formation in ThO2 slurries is presented. The sphere formation which occurs in "Standard" slurry can be explained on the same basis. The irregular and unpredictable yield strength is easily fitted into the theory. On the basis of this theory, the writer has been led to the conclusion that only colloidally stable slurries, or slurries with crystallites or comminution-resistant particles which are large enough to overcome colloidal effects (probably larger than 0.1u) can be used with assurance in the ThO2 reactor system. This conclusion holds for 300 gm/kg slurries as well as for more concentrated mixtures.

Factors affecting the results of thoria particle size distribution measurements by sedimentation procedures currently and recently employed are considered. The effects of thoria concentration, solvent, dispersant, thoria properties, and other factors are discussed.

General considerations involving the transportation of irradiated fuel and radioactive wastes are reviewed. It is assumed that many reactors will supply feed to a few large multipurpose chemical plants which ultimately send radioactive waste to a few disposal sites. General economic considerations of irradiated fuel reprocessing, economic aspects of the nuclear economy complex, growth predictions of the nuclear power economy in the U.S., general requirements for the shipment of fuel and waste, regulations applicable to fuel shipment, and permissible radiation levels are discussed.

Several compatibility test of various materials in contact in sodium under 500 psi pressure were conducted for 716 hr at 1500 F. Of the diffusion couples studies, the Inconel-beryllium system showed the largest amount al alloying. The reaction between molybdenum and beryllium resulted in the formation of two compounds, both of which were severely cracked in several areas. The molybdenum-INOR #8, and the INOR #8p type 316 stainless steel interfaces showed little if any alloying.

Data are presented for all toroid runs which circulated aqueous thorium oxide slurries between Aug, 1054, and October, 1956. In addition, a tabulation of the properties of numerous thoria preparations is presented.

This compilation includes the following subjects: (1) Spectroscopic studies, (2) Neutral carbon in the vacuum carbon arc, (3) Anode effects, doppler blast effects, and stark broadening, (4) Neutrals in the high-current carbon arc; (5) Photon breakup of N2 in the high-current carbon arc, (6) Ion density in the high current carbon arc, and (7) Recombination cross-section for fast hydrogen ions and slow electrons. Minor revisions have been made in the subject memoranda in incorporating them in the compilation.

The circuits described herein and shown functionally in Fig. 1 are to be added to the HRT control circuit to provide control and protection for the revised HRT cooling water system. The circuitry will provide protection against excess pressure in the demineralized cooling water loop and cooling water activity, will initiate action to insure containment of activity in event of an explosion and will provide emergency cooling water from the tower basin when required.

When it was discovered that two HRT flange bolts of a lot of 16 spares contained serious cracks, a program was launched to (1) determine the cause for the cracking, and (2) find methods for non-destructive testing the remainder of the 672 bolts shipment, a large portion of which had been installed in the HRT. Concurrently, inspection of 8 ferrules removed from an HRT flange revealed hairline cracking in 4 of them. Magnaglo, a magnetic particle inspection method using a fluorescent dye, proved to be the only definitive method for inspecting the bolts. The evidence gathered on the bolts pointed to quench cracking as the cause for the defects. Nothing abnormal was disclosed in regard to the bolt material. The alloy and heat treatment at present prescribed for the HRT bolts and ferrules are considered suitable. However, recommendations are made for plating with zinc, instead of formerly prescribed cadmium, to a thickness of 0.0002 inch, followed by a hydrogen relief treatment and a final bichromate chemical dip.

Short reports to the members of the Nuclear Cross Section Advisory Group from three groups: (1) High voltage group; (2) Fast chopper time-of flight spectrometer; and (3) Electronuclear research division.